Columbia Bond Fund

Summary of the Fund

Columbia Bond Fund

Summary of the Fund (continued)

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example illustrates the hypothetical expenses that you would incur over the time periods indicated, and assumes that:

■	you invest $10,000 in the applicable class of Fund shares for the periods indicated,
■	your investment has a 5% return each year, and
■	the Fund’s total annual operating expenses remain the same as shown in the Annual Fund Operating Expenses table above.

Since the waivers and/or reimbursements shown in the Annual Fund Operating Expenses table above expire as indicated in the preceding table, they are only reflected in the 1 year example and the first year of the other examples. Although your actual costs may be higher or lower, based on the assumptions listed above, your costs would be:

    

Portfolio Turnover

The Fund may pay transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 257% of the average value of its portfolio.

Principal Investment Strategies

Under normal circumstances, the Fund invests at least 80% of its net assets (including the amount of any borrowings for investment purposes) in bonds and other debt securities. The Fund generally invests at least 65% of its assets in debt securities issued by the U.S. Government and its agencies and instrumentalities, debt securities issued by corporations, and mortgage- and other asset-backed securities that, at the time of purchase, are rated in at least one of the three highest rating categories or are unrated but determined to be of comparable quality. The Fund may invest up to 25% of its net assets in debt instruments that, at the time of purchase, are rated below investment grade or are unrated but determined to be of comparable quality (commonly referred to as “high yield” investments or “junk” bonds).

The Fund may invest up to 25% of its assets in U.S. dollar-denominated foreign debt securities and instruments, including those of foreign governments, non-governmental issuers or other entities, and up to 20% of its assets in preferred stock. The Fund’s dollar-weighted average maturity and duration will vary over time depending on expectations for market and economic conditions.

4	Prospectus 2018

Columbia Bond Fund

Summary of the Fund (continued)

The Fund may invest in derivatives, such as futures (including interest rate futures) and swaps (including credit default swaps, credit default swap indexes, and interest rate swaps) for hedging and investment purposes, and to manage interest rate and/or credit exposure of the Fund.

The Fund may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis. Such securities may include mortgage-backed securities acquired or sold in the “to be announced” (TBA) market and those in a dollar roll transaction.

The Fund may invest in privately placed and other securities or instruments that are purchased and sold pursuant to Rule 144A or other exemptions under the Securities Act of 1933, as amended, subject to liquidity determinations and certain regulatory restrictions.

The Fund’s investment strategy may involve the frequent trading of portfolio securities.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Active Management Risk. Due to its active management, the Fund could underperform its benchmark index and/or other funds with similar investment objectives and/or strategies.

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The amount of the distributions the Fund pays will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains from its investments may reduce its distribution level.

Counterparty Risk. Counterparty risk is the risk that a counterparty to a transaction in a financial instrument held by the Fund or by a special purpose or structured vehicle invested in by the Fund may become insolvent or otherwise fail to perform its obligations. As a result, the Fund may obtain no or limited recovery of its investment, and any recovery may be significantly delayed.

Credit Risk. Credit risk is the risk that the value of debt instruments may decline if the issuer thereof defaults or otherwise becomes unable or unwilling, or is perceived to be unable or unwilling, to honor its financial obligations, such as making payments to the Fund when due. Rating agencies assign credit ratings to certain debt instruments to indicate their credit risk. Unless otherwise provided in the Fund’s Principal Investment Strategies, investment grade debt instruments are those rated at or above BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. Conversely, below investment grade (commonly called “high-yield” or “junk”) debt instruments are those rated below BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. A rating downgrade by such agencies can negatively impact the value of such instruments. Lower quality or unrated instruments held by the Fund may present increased credit risk as compared to higher-rated instruments. Non-investment grade debt instruments may be subject to greater price fluctuations and are more likely to experience a default than investment grade debt instruments and therefore may expose the Fund to increased credit risk. If the Fund purchases unrated instruments, or if the ratings of instruments held by the Fund are lowered after purchase, the Fund will depend on analysis of credit risk more heavily than usual.

Derivatives Risk. Derivatives may involve significant risks. Derivatives are financial instruments with a value in relation to, or derived from, the value of an underlying asset(s) or other reference, such as an index, rate or other economic indicator (each an underlying reference). Derivatives may include those that are privately placed or otherwise exempt from SEC registration, including certain Rule 144A eligible securities. Derivatives could result in Fund losses if the underlying reference does not perform as anticipated. Use of derivatives is a highly specialized activity that can involve investment techniques, risks, and tax planning different from those associated with more

Prospectus 2018

5

Columbia Bond Fund

Summary of the Fund (continued)

traditional investment instruments. The Fund’s derivatives strategy may not be successful and use of certain derivatives could result in substantial, potentially unlimited, losses to the Fund regardless of the Fund’s actual investment. A relatively small movement in the price, rate or other economic indicator associated with the underlying reference may result in substantial loss for the Fund. Derivatives may be more volatile than other types of investments. The value of derivatives may be influenced by a variety of factors, including national and international political and economic developments. Potential changes to the regulation of the derivatives markets may make derivatives more costly, may limit the market for derivatives, or may otherwise adversely affect the value or performance of derivatives. Derivatives can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk, foreign currency risk and interest rate risk, while exposing the Fund to correlation risk, counterparty risk, hedging risk, leverage risk, liquidity risk, pricing risk and volatility risk.

Derivatives Risk – Futures Contracts Risk. A futures contract is an exchange-traded derivative transaction between two parties in which a buyer (holding the “long” position) agrees to pay a fixed price (or rate) at a specified future date for delivery of an underlying reference from a seller (holding the “short” position). The seller hopes that the market price on the delivery date is less than the agreed upon price, while the buyer hopes for the contrary. Certain futures contract markets are highly volatile, and futures contracts may be illiquid. Futures exchanges may limit fluctuations in futures contract prices by imposing a maximum permissible daily price movement. The Fund may be disadvantaged if it is prohibited from executing a trade outside the daily permissible price movement. At or prior to maturity of a futures contract, the Fund may enter into an offsetting contract and may incur a loss to the extent there has been adverse movement in futures contract prices. The liquidity of the futures markets depends on participants entering into offsetting transactions rather than making or taking delivery. To the extent participants make or take delivery, liquidity in the futures market could be reduced. Because of the low margin deposits normally required in futures trading, it is possible that the Fund may employ a high degree of leverage in the portfolio. As a result, a relatively small price movement in a futures contract may result in substantial losses to the Fund, exceeding the amount of the margin paid. For certain types of futures contracts, losses are potentially unlimited. Futures markets are highly volatile and the use of futures may increase the volatility of the Fund’s NAV. Futures contracts executed (if any) on foreign exchanges may not provide the same protection as U.S. exchanges. Futures contracts can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk, foreign currency risk and interest rate risk, while also exposing the Fund to correlation risk, counterparty risk, hedging risk, leverage risk, liquidity risk, pricing risk and volatility risk.

Derivatives Risk – Swaps Risk. In a typical swap transaction, two parties agree to exchange the return earned on a specified underlying reference for a fixed return or the return from another underlying reference during a specified period of time. Swaps may be difficult to value and may be illiquid. Swaps could result in Fund losses if the underlying asset or reference does not perform as anticipated. Swaps create significant investment leverage such that a relatively small price movement in a swap may result in immediate and substantial losses to the Fund. The Fund may only close out a swap with its particular counterparty, and may only transfer a position with the consent of that counterparty. Certain swaps, such as short swap transactions and total return swaps, have the potential for unlimited losses, regardless of the size of the initial investment. Swaps can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk, foreign currency risk and interest rate risk, while also exposing the Fund to correlation risk, counterparty risk, hedging risk, inflation risk, leverage risk, liquidity risk, pricing risk and volatility risk.

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. Foreign securities subject the Fund to the risks associated with investing in the particular country of an issuer, including political, regulatory, economic, social, diplomatic and other conditions or events (including, for example, military confrontations, war and terrorism), occurring in the country or region, as well as risks associated with less developed custody and settlement practices. Foreign securities may be more volatile and less liquid than securities of U.S. companies, and are subject to the risks associated with potential imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities.

6	Prospectus 2018

Columbia Bond Fund

Summary of the Fund (continued)

Forward Commitments on Mortgage-Backed Securities (including Dollar Rolls) Risk. When purchasing mortgage-backed securities in the “to be announced” (TBA) market (MBS TBAs), the seller agrees to deliver mortgage-backed securities for an agreed upon price on an agreed upon date, but may make no guarantee as to the specific securities to be delivered. In lieu of taking delivery of mortgage-backed securities, the Fund could enter into dollar rolls, which are transactions in which the Fund sells securities to a counterparty and simultaneously agrees to purchase those or similar securities in the future at a predetermined price. Dollar rolls involve the risk that the market value of the securities the Fund is obligated to repurchase may decline below the repurchase price, or that the counterparty may default on its obligations. These transactions may also increase the Fund’s portfolio turnover rate. If the Fund reinvests the proceeds of the security sold, the Fund will also be subject to the risk that the investments purchased with such proceeds will decline in value (a form of leverage risk). MBS TBAs and dollar rolls are subject to the risk that the counterparty to the transaction may not perform or be unable to perform in accordance with the terms of the instrument.

Frequent Trading Risk.  The portfolio managers may actively and frequently trade investments in the Fund's portfolio to carry out its investment strategies. Frequent trading of investments increases the possibility that the Fund, as relevant, will realize taxable capital gains (including short-term capital gains, which are generally taxable to shareholders at higher rates than long-term capital gains for U.S. federal income tax purposes), which could reduce the Fund's after-tax return. Frequent trading can also mean higher brokerage and other transaction costs, which could reduce the Fund's return. The trading costs and tax effects associated with portfolio turnover may adversely affect the Fund’s performance.

High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality expose the Fund to a greater risk of loss of principal and income than a fund that invests solely or primarily in investment grade debt instruments. In addition, these investments have greater price fluctuations, are less liquid and are more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal.

Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if prevailing interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk. Similarly, a period of rising interest rates may negatively impact the Fund’s performance. Actions by governments and central banking authorities can result in increases in interest rates. Such actions may negatively affect the value of debt instruments held by the Fund, resulting in a negative impact on the Fund's performance and NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Decreases in the number of financial institutions, including banks and broker-dealers, willing to make markets (match up sellers and buyers) in the Fund’s investments or decreases in their capacity or willingness to trade such investments may increase the Fund’s exposure to this risk.

Prospectus 2018

7

Columbia Bond Fund

Summary of the Fund (continued)

The debt market has experienced considerable growth, and financial institutions making markets in instruments purchased and sold by the Fund (e.g., bond dealers) have been subject to increased regulation. The impact of that growth and regulation on the ability and willingness of financial institutions to engage in trading or “making a market” in such instruments remains unsettled. Certain types of investments, such as lower-rated securities or those that are purchased and sold in over-the-counter markets, may be especially subject to liquidity risk. Securities or other assets in which the Fund invests may be traded in the over-the-counter market rather than on an exchange and therefore may be more difficult to purchase or sell at a fair price, which may have a negative impact on the Fund’s performance. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. An investment in the Fund could lose money over short or long periods.

Mortgage- and Other Asset-Backed Securities Risk. The value of any mortgage-backed and other asset-backed securities held by the Fund may be affected by, among other things, changes or perceived changes in: interest rates; factors concerning the interests in and structure of the issuer or the originator of the mortgages or other assets; the creditworthiness of the entities that provide any supporting letters of credit, surety bonds or other credit enhancements; or the market's assessment of the quality of underlying assets. Payment of principal and interest on some mortgage-backed securities (but not the market value of the securities themselves) may be guaranteed by the full faith and credit of a particular U.S. Government agency, authority, enterprise or instrumentality, and some, but not all, are also insured or guaranteed by the U.S. Government. Mortgage-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) may entail greater risk than obligations guaranteed by the U.S. Government. Mortgage- and other asset-backed securities are subject to prepayment risk, which is the possibility that the underlying mortgage or other asset may be refinanced or prepaid prior to maturity during periods of declining or low interest rates, causing the Fund to have to reinvest the money received in securities that have lower yields. Rising or high interest rates tend to extend the duration of mortgage- and other asset-backed securities, making their prices more volatile and more sensitive to changes in interest rates.

Preferred Stock Risk. Preferred stock is a type of stock that generally pays dividends at a specified rate and that has preference over common stock in the payment of dividends and the liquidation of assets. Preferred stock does not ordinarily carry voting rights. The price of a preferred stock is generally determined by earnings, type of products or services, projected growth rates, experience of management, liquidity, and general market conditions of the markets on which the stock trades. The most significant risks associated with investments in preferred stock include issuer risk, market risk and interest rate risk ( i.e. , the risk of losses attributable to changes in interest rates).

Prepayment and Extension Risk. Prepayment and extension risk is the risk that a bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. In the case of mortgage- or other asset-backed securities, as interest rates decrease or spreads

8	Prospectus 2018

Columbia Bond Fund

Summary of the Fund (continued)

narrow, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in interest rates will extend the life of a mortgage- or asset-backed security beyond the prepayment time. If the Fund’s investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on securities with higher interest rates or wider spreads.

Reinvestment Risk. Reinvestment risk is the risk that the Fund will not be able to reinvest income or principal at the same return it is currently earning.

Rule 144A and Other Exempted Securities Risk. The Fund may invest in privately placed and other securities or instruments exempt from SEC registration (collectively “private placements”), subject to liquidity and other regulatory restrictions. In the U.S. market, private placements are typically sold only to qualified institutional buyers, or qualified purchasers, as applicable. An insufficient number of buyers interested in purchasing private placements at a particular time could adversely affect the marketability of such investments and the Fund might be unable to dispose of them promptly or at reasonable prices, subjecting the Fund to liquidity risk. The Fund may invest in private placements determined to be liquid as well as those determined to be illiquid. Even if determined to be liquid, the Fund’s holdings of private placements may increase the level of Fund illiquidity if eligible buyers are unable or unwilling to purchase them at a particular time. Issuers of Rule 144A eligible securities are required to furnish information to potential investors upon request. However, the required disclosure is much less extensive than that required of public companies and is not publicly available since the offering is not filed with the SEC. Further, issuers of Rule 144A eligible securities can require recipients of the offering information (such as the Fund) to agree contractually to keep the information confidential, which could also adversely affect the Fund’s ability to dispose of the security.

U.S. Government Obligations Risk. While U.S. Treasury obligations are backed by the “full faith and credit” of the U.S. Government, such securities are nonetheless subject to credit risk (i.e., the risk that the U.S. Government may be, or be perceived to be, unable or unwilling to honor its financial obligations, such as making payments). Securities issued or guaranteed by federal agencies or authorities and U.S. Government-sponsored instrumentalities or enterprises may or may not be backed by the full faith and credit of the U.S. Government.

Performance Information

The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s Class Inst share performance has varied for each full calendar year shown. The table below the bar chart compares the Fund’s returns (after applicable sales charges shown in the Shareholder Fees table in this prospectus) for the periods shown with a broad measure of market performance.

The performance of one or more share classes shown in the table below begins before the indicated inception date for such share class. The returns shown for each such share class include the returns of the Fund’s Class Inst shares (adjusted to reflect the higher class-related operating expenses of such classes, where applicable) for periods prior to its inception date. Except for differences in annual returns resulting from differences in expenses and sales charges (where applicable), the share classes of the Fund would have substantially similar annual returns because all share classes of the Fund invest in the same portfolio of securities.

The returns shown for the Fund include the returns of Core Bond Fund, the predecessor to the Fund and a series of Excelsior Funds, Inc., for periods prior to March 31, 2008.

The after-tax returns shown in the Average Annual Total Returns table below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the table and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the table. In addition, the after-tax returns shown in the table do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs). The after-tax returns are shown only for Class Inst shares and will vary for other share classes.

Prospectus 2018

9

Columbia Bond Fund

Summary of the Fund (continued)

The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 800.345.6611 or visiting columbiathreadneedleus.com.

    

Year by Year Total Return (%) as of December 31 Each Year*	Best and Worst Quarterly Returns During the Period Shown in the Bar Chart
	Best	3rd Quarter 2009	4.55%
	Worst	4th Quarter 2016	-2.79%

*	Year to Date return as of June 30, 2018: -1.75%

  

10	Prospectus 2018

Columbia Bond Fund

Summary of the Fund (continued)

Tax Information

The Fund normally distributes net investment income and net realized capital gains, if any, to shareholders. These distributions are generally taxable to you as ordinary income or capital gains, unless you are investing through a tax-advantaged account, such as a 401(k) plan or an IRA. If you are investing through a tax-advantaged account, you may be taxed upon withdrawals from that account.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies — including Columbia Management Investment Advisers, LLC (the Investment Manager), Columbia Management Investment Distributors, Inc. (the Distributor) and Columbia Management Investment Services Corp. (the Transfer Agent) — may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary’s website for more information.

12	Prospectus 2018

Columbia Bond Fund

More Information About the Fund

Columbia Bond Fund

More Information About the Fund (continued)

The Fund’s investment policy with respect to 80% of its net assets may be changed by the Fund’s Board of Trustees without shareholder approval as long as shareholders are given 60 days’ advance written notice of the change. Additionally, shareholders will be given 60 days’ notice of any change to the Fund’s investment objective made to comply with the SEC rule governing investment company names.

Principal Risks

An investment in the Fund involves risks, including those described below. There is no assurance that the Fund will achieve its investment objective and you may lose money . The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Active Management Risk. The Fund is actively managed and its performance therefore will reflect, in part, the ability of the portfolio managers to make investment decisions that seek to achieve the Fund’s investment objective. Due to its active management, the Fund could underperform its benchmark index and/or other funds with similar investment objectives and/or strategies.

Changing Distribution Level Risk. The Fund will normally receive income which may include interest, dividends and/or capital gains, depending upon its investments. The amount of the distributions the Fund pays will vary and generally depends on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains from its investments may reduce its distribution level.

Counterparty Risk. The risk exists that a counterparty to a transaction in a financial instrument held by the Fund or by a special purpose or structured vehicle in which the Fund invests may become insolvent or otherwise fail to perform its obligations due to financial difficulties, including making payments to the Fund. The Fund may obtain no or limited recovery in a bankruptcy or other reorganizational proceedings, and any recovery may be significantly delayed. Transactions that the Fund enters into may involve counterparties in the financial services sector and, as a result, events affecting the financial services sector may cause the Fund’s share value to fluctuate.

Credit Risk. Credit risk is the risk that the value of debt instruments may decline if the issuer thereof defaults or otherwise becomes unable or unwilling, or is perceived to be unable or unwilling, to honor its financial obligations, such as making payments to the Fund when due. Various factors could affect the actual or perceived willingness or ability of the issuer to make timely interest or principal payments, including changes in the financial condition of the issuer or in general economic conditions. Rating agencies assign credit ratings to certain debt instruments to indicate their credit risk. Unless otherwise provided in the Fund’s Principal Investment Strategies, investment grade debt instruments are those rated at or above BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. Conversely, below investment grade (commonly called “high-yield” or “junk”) debt instruments are those rated below BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. A rating downgrade by such agencies can negatively impact the value of such instruments. Lower quality or unrated instruments held by the Fund may present increased credit risk as compared to higher-rated instruments. Non-investment grade debt instruments may be subject to greater price fluctuations and are more likely to experience a default than investment grade debt instruments and therefore may expose the Fund to increased credit risk. If the Fund purchases unrated instruments, or if the ratings of instruments held by the Fund are lowered after purchase, the Fund will depend on analysis of credit risk more heavily than usual.

Derivatives Risk. Derivatives may involve significant risks. Derivatives are financial instruments, traded on an exchange or in the over-the-counter (OTC) markets, with a value in relation to, or derived from, the value of an underlying asset(s) (such as a security, commodity or currency) or other reference, such as an index, rate or other economic indicator (each an underlying reference). Derivatives may include those that are privately placed or otherwise exempt from SEC registration, including certain Rule 144A eligible securities. Derivatives could result in Fund losses if the underlying reference does not perform as anticipated. Use of derivatives is a highly specialized activity that can involve investment techniques, risks, and tax planning different from those associated with more

14	Prospectus 2018

Columbia Bond Fund

More Information About the Fund (continued)

traditional investment instruments. The Fund’s derivatives strategy may not be successful and use of certain derivatives could result in substantial, potentially unlimited, losses to the Fund regardless of the Fund’s actual investment. A relatively small movement in the price, rate or other economic indicator associated with the underlying reference may result in substantial loss for the Fund. Derivatives may be more volatile than other types of investments. Derivatives can increase the Fund’s risk exposure to underlying references and their attendant risks, including the risk of an adverse credit event associated with the underlying reference (credit risk), the risk of an adverse movement in the value, price or rate of the underlying reference (market risk), the risk of an adverse movement in the value of underlying currencies (foreign currency risk) and the risk of an adverse movement in underlying interest rates (interest rate risk). Derivatives may expose the Fund to additional risks, including the risk of loss due to a derivative position that is imperfectly correlated with the underlying reference it is intended to hedge or replicate (correlation risk), the risk that a counterparty will fail to perform as agreed (counterparty risk), the risk that a hedging strategy may fail to mitigate losses, and may offset gains (hedging risk), the risk that losses may be greater than the amount invested (leverage risk), the risk that the Fund may be unable to sell an investment at an advantageous time or price (liquidity risk), the risk that the investment may be difficult to value (pricing risk), and the risk that the price or value of the investment fluctuates significantly over short periods of time (volatility risk). The value of derivatives may be influenced by a variety of factors, including national and international political and economic developments. Potential changes to the regulation of the derivatives markets may make derivatives more costly, may limit the market for derivatives, or may otherwise adversely affect the value or performance of derivatives.

Derivatives Risk – Futures Contracts Risk. A futures contract is an exchange-traded derivative transaction between two parties in which a buyer (holding the “long” position) agrees to pay a fixed price (or rate) at a specified future date for delivery of an underlying reference from a seller (holding the “short” position). The seller hopes that the market price on the delivery date is less than the agreed upon price, while the buyer hopes for the contrary. Certain futures contract markets are highly volatile, and futures contracts may be illiquid. Futures exchanges may limit fluctuations in futures contract prices by imposing a maximum permissible daily price movement. The Fund may be disadvantaged if it is prohibited from executing a trade outside the daily permissible price movement. At or prior to maturity of a futures contract, the Fund may enter into an offsetting contract and may incur a loss to the extent there has been adverse movement in futures contract prices. The liquidity of the futures markets depends on participants entering into offsetting transactions rather than making or taking delivery. To the extent participants make or take delivery, liquidity in the futures market could be reduced. Positions in futures contracts may be closed out only on the exchange on which they were entered into or through a linked exchange, and no secondary market exists for such contracts. Futures positions are marked to market each day and variation margin payment must be paid to or by the Fund. Because of the low margin deposits normally required in futures trading, it is possible that the Fund may employ a high degree of leverage in the portfolio. As a result, a relatively small price movement in a futures contract may result in substantial losses to the Fund, exceeding the amount of the margin paid. For certain types of futures contracts, losses are potentially unlimited. Futures markets are highly volatile and the use of futures may increase the volatility of the Fund’s NAV. Futures contracts executed (if any) on foreign exchanges may not provide the same protection as U.S. exchanges. Futures contracts can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk, foreign currency risk and interest rate risk, while also exposing the Fund to correlation risk, counterparty risk, hedging risk, leverage risk, liquidity risk, pricing risk and volatility risk.

■	An interest rate future is a derivative that is an agreement whereby the buyer and seller agree to the future delivery of an interest-bearing instrument on a specific date at a pre-determined price. Examples include Treasury-bill futures, Treasury-bond futures and Eurodollar futures.

Derivatives Risk – Swaps Risk. In a typical swap transaction, two parties agree to exchange the return earned on a specified underlying reference for a fixed return or the return from another underlying reference during a specified period of time. Swaps may be difficult to value and may be illiquid. Swaps could result in Fund losses if the underlying asset or reference does not perform as anticipated. Swaps create significant investment leverage such that a relatively small price movement in a swap may result in immediate and substantial losses to the Fund. The Fund may only close out a swap with its particular counterparty, and may only transfer a position with the consent of that counterparty. Certain swaps, such as short swap transactions and total return swaps, have the potential for

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unlimited losses, regardless of the size of the initial investment. Swaps can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk, foreign currency risk and interest rate risk, while also exposing the Fund to correlation risk, counterparty risk, hedging risk, inflation risk, leverage risk, liquidity risk, pricing risk and volatility risk.

■

A credit default swap (including a swap on a credit default index, sometimes referred to as a credit default swap index) is a derivative and special type of swap where one party pays, in effect, an insurance premium through a stream of payments to another party in exchange for the right to receive a specified return upon the occurrence of a particular credit event by one or more third parties, such as bankruptcy, default or a similar event. A credit default swap may be embedded within a structured note or other derivative instrument. Credit default swaps enable an investor to buy or sell protection against such a credit event (such as an issuer’s bankruptcy, restructuring or failure to make timely payments of interest or principal). Credit default swap indices are indices that reflect the performance of a basket of credit default swaps and are subject to the same risks as credit default swaps. If such a default were to occur, any contractual remedies that the Fund may have may be subject to bankruptcy and insolvency laws, which could delay or limit the Fund's recovery. Thus, if the counterparty under a credit default swap defaults on its obligation to make payments thereunder, as a result of its bankruptcy or otherwise, the Fund may lose such payments altogether, or collect only a portion thereof, which collection could involve costs or delays. The Fund’s return from investment in a credit default swap index may not match the return of the referenced index. Further, investment in a credit default swap index could result in losses if the referenced index does not perform as expected. Unexpected changes in the composition of the index may also affect performance of the credit default swap index. If a referenced index has a dramatic intraday move that causes a material decline in the Fund’s net assets, the terms of the Fund’s credit default swap index may permit the counterparty to immediately close out the transaction. In that event, the Fund may be unable to enter into another credit default swap index or otherwise achieve desired exposure, even if the referenced index reverses all or a portion of its intraday move.

■

An interest rate swap is a derivative in which two parties agree to exchange interest rate cash flows, based on a specified notional amount from a fixed rate to a floating rate (or vice versa) or from one floating rate to another. Interest rate swaps can be based on various measures of interest rates, including LIBOR, swap rates, treasury rates and foreign interest rates.

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. For example, foreign markets can be extremely volatile. Foreign securities may also be less liquid than securities of U.S. companies so that the Fund may, at times, be unable to sell foreign securities at desirable times or prices. Brokerage commissions, custodial costs and other fees are also generally higher for foreign securities. The Fund may have limited or no legal recourse in the event of default with respect to certain foreign securities, including those issued by foreign governments. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities. In some cases, such withholding or other taxes could potentially be confiscatory. Other risks include: possible delays in the settlement of transactions or in the payment of income; generally less publicly available information about foreign companies; the impact of economic, political, social, diplomatic or other conditions or events (including, for example, military confrontations, war and terrorism), possible seizure, expropriation or nationalization of a company or its assets or the assets of a particular investor or category of investors; accounting, auditing and financial reporting standards that may be less comprehensive and stringent than those applicable to domestic companies; the imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country; and the generally less stringent standard of care to which local agents may be held in the local markets. In addition, it may be difficult to obtain reliable information about the securities and business operations of certain foreign issuers. Governments or trade groups may compel local agents to hold securities in designated depositories that are not subject to independent evaluation. The less developed a country’s securities market is, the greater the level of risks. The risks posed by sanctions against a particular foreign country, its nationals or industries or businesses within the country may be heightened to the extent the Fund invests significantly in the affected country or region or in issuers from the affected country that depend on global markets. Additionally, investments in certain countries

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may subject the Fund to a number of tax rules, the application of which may be uncertain. Countries may amend or revise their existing tax laws, regulations and/or procedures in the future, possibly with retroactive effect. Changes in or uncertainties regarding the laws, regulations or procedures of a country could reduce the after-tax profits of the Fund, directly or indirectly, including by reducing the after-tax profits of companies located in such countries in which the Fund invests, or result in unexpected tax liabilities for the Fund.

Forward Commitments on Mortgage-Backed Securities (including Dollar Rolls) Risk. When purchasing mortgage-backed securities in the “to be announced” (TBA) market (MBS TBAs), the seller agrees to deliver mortgage-backed securities for an agreed upon price on an agreed upon date, but may make no guarantee as to the specific securities to be delivered. In lieu of taking delivery of mortgage-backed securities, the Fund could enter into dollar rolls, which are transactions in which the Fund sells securities to a counterparty and simultaneously agrees to purchase those or similar securities in the future at a predetermined price. Dollar rolls involve the risk that the market value of the securities the Fund is obligated to repurchase may decline below the repurchase price, or that the counterparty may default on its obligations. These transactions may also increase the Fund’s portfolio turnover rate. If the Fund reinvests the proceeds of the security sold, the Fund will also be subject to the risk that the investments purchased with such proceeds will decline in value (a form of leverage risk). MBS TBAs and dollar rolls are subject to the risk that the counterparty to the transaction may not perform or be unable to perform in accordance with the terms of the instrument.

Frequent Trading Risk.  The portfolio managers may actively and frequently trade investments in the Fund's portfolio to carry out its investment strategies. Frequent trading of investments increases the possibility that the Fund, as relevant, will realize taxable capital gains (including short-term capital gains, which are generally taxable to shareholders at higher rates than long-term capital gains for U.S. federal income tax purposes), which could reduce the Fund's after-tax return. Frequent trading can also mean higher brokerage and other transaction costs, which could reduce the Fund's return. The trading costs and tax effects associated with portfolio turnover may adversely affect the Fund’s performance.

High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality tend to be more sensitive to credit risk than higher-rated debt instruments and may experience greater price fluctuations in response to perceived changes in the ability of the issuing entity or obligor to pay interest and principal when due than to changes in interest rates. These investments are generally more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal. These debt instruments typically pay a premium – a higher interest rate or yield – because of the increased risk of loss, including default. High-yield debt instruments may require a greater degree of judgment to establish a price, may be difficult to sell at the time and price the Fund desires, may carry high transaction costs, and also are generally less liquid than higher-rated debt instruments. The ratings provided by third party rating agencies are based on analyses by these ratings agencies of the credit quality of the debt instruments and may not take into account every risk related to whether interest or principal will be timely repaid. In adverse economic and other circumstances, issuers of lower-rated debt instruments are more likely to have difficulty making principal and interest payments than issuers of higher-rated debt instruments.

Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if prevailing interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk. Similarly, a period of rising interest rates may negatively impact the Fund’s performance. Actions by governments and central banking authorities can result in increases in interest rates. Such actions may negatively affect the value of debt instruments held by the

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Fund, resulting in a negative impact on the Fund's performance and NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Decreases in the number of financial institutions, including banks and broker-dealers, willing to make markets (match up sellers and buyers) in the Fund’s investments or decreases in their capacity or willingness to trade such investments may increase the Fund’s exposure to this risk. The debt market has experienced considerable growth, and financial institutions making markets in instruments purchased and sold by the Fund (e.g., bond dealers) have been subject to increased regulation. The impact of that growth and regulation on the ability and willingness of financial institutions to engage in trading or “making a market” in such instruments remains unsettled. Certain types of investments, such as lower-rated securities or those that are purchased and sold in over-the-counter markets, may be especially subject to liquidity risk. Securities or other assets in which the Fund invests may be traded in the over-the-counter market rather than on an exchange and therefore may be more difficult to purchase or sell at a fair price, which may have a negative impact on the Fund’s performance. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. The value of Fund investments may fall or fail to rise because of a variety of actual or perceived factors affecting an issuer (e.g., unfavorable news), the industry or sector in which it operates, or the market as a whole, which may reduce the value of an investment in the Fund. Accordingly, an investment in the Fund could lose money over short or long periods. The market values of the investments the Fund holds can be affected by changes or potential or perceived changes in U.S. or foreign economies, financial markets, interest rates and the liquidity of these investments, among other factors.

Mortgage- and Other Asset-Backed Securities Risk. The value of any mortgage-backed and other asset-backed securities held by the Fund may be affected by, among other things, changes or perceived changes in: interest rates; factors concerning the interests in and structure of the issuer or the originator of the mortgages or other assets; the creditworthiness of the entities that provide any supporting letters of credit, surety bonds or other credit enhancements; or the market's assessment of the quality of underlying assets. Mortgage-backed securities represent interests in, or are backed by, pools of mortgages from which payments of interest and principal (net of fees paid to the issuer or guarantor of the securities) are distributed to the holders of the mortgage-backed

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securities. Other types of asset-backed securities typically represent interests in, or are backed by, pools of receivables such as credit, automobile, student and home equity loans. Mortgage- and other asset-backed securities can have a fixed or an adjustable rate. Mortgage- and other asset-backed securities are subject to prepayment risk, which is the possibility that the underlying mortgage or other asset may be refinanced or prepaid prior to maturity during periods of declining or low interest rates, causing the Fund to have to reinvest the money received in securities that have lower yields. In addition, the impact of prepayments on the value of mortgage- and other asset-backed securities may be difficult to predict and may result in greater volatility. Rising or high interest rates tend to extend the duration of mortgage- and other asset-backed securities, making them more volatile and more sensitive to changes in interest rates. Payment of principal and interest on some mortgage-backed securities (but not the market value of the securities themselves) may be guaranteed (i) by the full faith and credit of the U.S. Government (in the case of securities guaranteed by the Government National Mortgage Association) or (ii) by its agencies, authorities, enterprises or instrumentalities (in the case of securities guaranteed by the Federal National Mortgage Association (FNMA) or the Federal Home Loan Mortgage Corporation (FHLMC)), which are not insured or guaranteed by the U.S. Government (although FNMA and FHLMC may be able to access capital from the U.S. Treasury to meet their obligations under such securities). Mortgage-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) may be supported by various credit enhancements, such as pool insurance, guarantees issued by governmental entities, letters of credit from a bank or senior/subordinated structures, and may entail greater risk than obligations guaranteed by the U.S. Government, whether or not such obligations are guaranteed by the private issuer.

Preferred Stock Risk. Preferred stock is a type of stock that generally pays dividends at a specified rate and that has preference over common stock in the payment of dividends and the liquidation of assets. Preferred stock does not ordinarily carry voting rights. The price of a preferred stock is generally determined by earnings, type of products or services, projected growth rates, experience of management, liquidity, and general market conditions of the markets on which the stock trades. The most significant risks associated with investments in preferred stock include issuer risk, market risk and interest rate risk ( i.e. , the risk of losses attributable to changes in interest rates).

Prepayment and Extension Risk. Prepayment and extension risk is the risk that a bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. In the case of mortgage- or other asset-backed securities, as interest rates decrease or spreads narrow, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in interest rates will extend the life of a mortgage- or asset-backed security beyond the prepayment time. If the Fund's investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on securities with higher interest rates or wider spreads.

Reinvestment Risk. Reinvestment risk is the risk that the Fund will not be able to reinvest income or principal at the same return it is currently earning.

Rule 144A and Other Exempted Securities Risk. The Fund may invest in privately placed and other securities or instruments exempt from SEC registration (collectively “private placements”), subject to liquidity and other regulatory restrictions. In the U.S. market, private placements are typically sold only to qualified institutional buyers, or qualified purchasers, as applicable. An insufficient number of buyers interested in purchasing private placements at a particular time could adversely affect the marketability of such investments and the Fund might be unable to dispose of them promptly or at reasonable prices, subjecting the Fund to liquidity risk. The Fund may invest in private placements determined to be liquid as well as those determined to be illiquid. Even if determined to be liquid, the Fund’s holdings of private placements may increase the level of Fund illiquidity if eligible buyers are unable or unwilling to purchase them at a particular time. The Fund may also have to bear the expense of registering the securities for resale and the risk of substantial delays in effecting the registration. Additionally, the purchase price and subsequent valuation of private placements typically reflect a discount, which may be significant, from the market price of comparable securities for which a more liquid market exists. Issuers of Rule 144A eligible securities

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are required to furnish information to potential investors upon request. However, the required disclosure is much less extensive than that required of public companies and is not publicly available since the offering is not filed with the SEC. Further, issuers of Rule 144A eligible securities can require recipients of the offering information (such as the Fund) to agree contractually to keep the information confidential, which could also adversely affect the Fund’s ability to dispose of the security.

U.S. Government Obligations Risk. While U.S. Treasury obligations are backed by the “full faith and credit” of the U.S. Government, such securities are nonetheless subject to credit risk ( i.e. , the risk that the U.S. Government may be, or may be perceived to be, unable or unwilling to honor its financial obligations, such as making payments). Securities issued or guaranteed by federal agencies or authorities and U.S. Government-sponsored instrumentalities or enterprises may or may not be backed by the full faith and credit of the U.S. Government. For example, securities issued by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association and the Federal Home Loan Banks are neither insured nor guaranteed by the U.S. Government. These securities may be supported by the ability to borrow from the U.S. Treasury or only by the credit of the issuing agency, authority, instrumentality or enterprise and, as a result, are subject to greater credit risk than securities issued or guaranteed by the U.S. Treasury.

Additional Investment Strategies and Policies

This section describes certain investment strategies and policies that the Fund may utilize in pursuit of its investment objective and some additional factors and risks involved with investing in the Fund.

Investment Guidelines

As a general matter, and except as specifically described in the discussion of the Fund's principal investment strategies in this prospectus or as otherwise required by the Investment Company Act of 1940, as amended (the 1940 Act), the rules and regulations thereunder and any applicable exemptive relief, whenever an investment policy or limitation states a percentage of the Fund's assets that may be invested in any security or other asset or sets forth a policy regarding an investment standard, compliance with that percentage limitation or standard will be determined solely at the time of the Fund's investment in the security or asset.

Holding Other Kinds of Investments

The Fund may hold other investments that are not part of its principal investment strategies. These investments and their risks are described below and/or in the SAI. The Fund may choose not to invest in certain securities described in this prospectus and in the SAI, although it has the ability to do so. Information on the Fund’s holdings can be found in the Fund’s shareholder reports or by visiting columbiathreadneedleus.com.

Transactions in Derivatives

The Fund may enter into derivative transactions or otherwise have exposure to derivative transactions through underlying investments. Derivatives are financial contracts whose values are, for example, based on (or “derived” from) traditional securities (such as a stock or bond), assets (such as a commodity like gold or a foreign currency), reference rates (such as the London Interbank Offered Rate (commonly known as LIBOR)) or market indices (such as the Standard & Poor's (S&P) 500 ^® Index). The use of derivatives is a highly specialized activity which involves investment techniques and risks different from those associated with ordinary portfolio securities transactions. Derivatives involve special risks and may result in losses or may limit the Fund's potential gain from favorable market movements. Derivative strategies often involve leverage, which may exaggerate a loss, potentially causing the Fund to lose more money than it would have lost had it invested in the underlying security or other asset directly. The values of derivatives may move in unexpected ways, especially in unusual market conditions, and may result in increased volatility in the value of the derivative and/or the Fund’s shares, among other consequences. The use of derivatives may also increase the amount of taxes payable by shareholders holding shares in a taxable account. Other risks arise from the Fund's potential inability to terminate or to sell derivative positions. A liquid secondary market may not always exist for the Fund's derivative positions at times when the Fund might wish to terminate or to sell such positions. Over-the-counter instruments (investments not traded on an exchange) may be illiquid, and transactions in derivatives traded in the over-the-counter market are subject to the risk that the other party will not meet its

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obligations. The use of derivatives also involves the risks of mispricing or improper valuation and that changes in the value of the derivative may not correlate perfectly with the underlying security, asset, reference rate or index. The Fund also may not be able to find a suitable derivative transaction counterparty, and thus may be unable to engage in derivative transactions when it is deemed favorable to do so, or at all. U.S. federal legislation has been enacted that provides for new clearing, margin, reporting and registration requirements for participants in the derivatives market. These changes could restrict and/or impose significant costs or other burdens upon the Fund’s participation in derivatives transactions. For more information on the risks of derivative investments and strategies, see the SAI.

Affiliated Fund Investing

The Investment Manager or an affiliate serves as investment adviser to funds using the Columbia brand (Columbia Funds), including those that are structured as “fund-of-funds”, and provides asset-allocation services to (i) shareholders by investing in shares of other Columbia Funds, which may include the Fund (collectively referred to in this section as Underlying Funds), and (ii) discretionary managed accounts (collectively referred to as affiliated products) that invest exclusively in Underlying Funds. These affiliated products, individually or collectively, may own a significant percentage of the outstanding shares of one or more Underlying Funds, and the Investment Manager seeks to balance potential conflicts of interest between the affiliated products and the Underlying Funds in which they invest. The affiliated products’ investment in the Underlying Funds may have the effect of creating economies of scale, possibly resulting in lower expense ratios for the Underlying Funds, because the affiliated products may own substantial portions of the shares of Underlying Funds. However, redemption of Underlying Fund shares by one or more affiliated products could cause the expense ratio of an Underlying Fund to increase, as its fixed costs would be spread over a smaller asset base. Because of large positions of certain affiliated products, the Underlying Funds may experience relatively large inflows and outflows of cash due to affiliated products’ purchases and sales of Underlying Fund shares. Although the Investment Manager or its affiliate may seek to minimize the impact of these transactions where possible, for example, by structuring them over a reasonable period of time or through other measures, Underlying Funds may experience increased expenses as they buy and sell portfolio securities to manage the cash flow effect related to these transactions. Further, when the Investment Manager or its affiliate structures transactions over a reasonable period of time in order to manage the potential impact of the buy and sell decisions for the affiliated products, those affiliated products, including funds-of-funds, may pay more or less (for purchase activity), or receive more or less (for redemption activity), for shares of the Underlying Funds than if the transactions were executed in one transaction. In addition, substantial redemptions by affiliated products within a short period of time could require the Underlying Fund to liquidate positions more rapidly than would otherwise be desirable, which may have the effect of reducing or eliminating potential gain or causing it to realize a loss. In order to meet such redemptions, an Underlying Fund may be forced to sell its liquid (or more liquid) positions, leaving the Underlying Fund holding, post-redemption, a relatively larger position in illiquid securities (securities that are not readily marketable or that cannot be sold or disposed of in the ordinary course of business, within seven days, at approximately the value at which the holder has valued the security) or less liquid securities. Substantial redemptions may also adversely affect the ability of the Underlying Fund to implement its investment strategy. The Investment Manager or its affiliate also has a conflict of interest in determining the allocation of affiliated products’ assets among the Underlying Funds, as it earns different fees from the various Underlying Funds.

Investing in Money Market Funds

The Fund may invest cash in, or hold as collateral for certain investments, shares of registered or unregistered money market funds, including funds advised by the Investment Manager or its affiliates. These funds are not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. The Fund and its shareholders indirectly bear a portion of the expenses of any money market fund or other fund in which the Fund may invest.

Lending of Portfolio Securities

The Fund may lend portfolio securities to broker-dealers or other financial intermediaries on a fully collateralized basis in order to earn additional income. The Fund may lose money from securities lending if, for example, it is delayed in or prevented from selling the collateral after the loan is made or recovering the securities loaned or if it incurs losses on the reinvestment of cash collateral.

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The Fund currently does not participate in the securities lending program but the Board of Trustees (the Board) may determine to renew participation in the future. For more information on lending of portfolio securities and the risks involved, see the SAI and the annual and semiannual reports to shareholders.

Investing Defensively

The Fund may from time to time take temporary defensive investment positions that may be inconsistent with the Fund’s principal investment strategies in attempting to respond to adverse market, economic, political, social or other conditions, including, without limitation, investing some or all of its assets in money market instruments or shares of affiliated or unaffiliated money market funds or holding some or all of its assets in cash or cash equivalents. The Fund may take such defensive investment positions for as long a period as deemed necessary.

The Fund may not achieve its investment objective while it is investing defensively. Investing defensively may adversely affect Fund performance. During these times, the portfolio managers may make frequent portfolio holding changes, which could result in increased trading expenses and taxes, and decreased Fund performance. See also Investing in Money Market Funds above for more information.

Other Strategic and Investment Measures

The Fund may also from time to time take temporary portfolio positions that may or may not be consistent with the Fund’s principal investment strategies in attempting to respond to adverse market, economic, political, social or other conditions, including, without limitation, investing in derivatives, such as forward contracts, futures contracts, options, structured investments and swaps, for various purposes, including among others, investing in particular derivatives in seeking to reduce investment exposures, or in seeking to achieve indirect investment exposures, to a sector, country, region or currency where the Investment Manager believes such positioning is appropriate. The Fund may take such portfolio positions for as long a period as deemed necessary. While the Fund is so positioned, derivatives could comprise a substantial portion of the Fund’s investments and the Fund may not achieve its investment objective. Investing in this manner may adversely affect Fund performance. During these times, the portfolio managers may make frequent portfolio holding changes, which could result in increased trading expenses and taxes, and decreased Fund performance. For information on the risks of investing in derivatives, see Transactions in Derivatives above.

Portfolio Holdings Disclosure

The Board has adopted policies and procedures that govern the timing and circumstances of disclosure to shareholders and third parties of information regarding the securities owned by the Fund. A description of these policies and procedures is included in the SAI. Fund policy generally permits the disclosure of portfolio holdings information on the Fund's website (columbiathreadneedleus.com) only after a certain amount of time has passed, as described in the SAI.

Purchases and sales of portfolio securities can take place at any time, so the portfolio holdings information available on the Fund's website may not always be current.

eDelivery and Mailings to Households

In order to reduce shareholder expenses, the Fund may mail only one copy of the Fund’s prospectus and each annual and semiannual report to those addresses shared by two or more accounts. If you wish to receive separate copies of these documents, call 800.345.6611 or, if your shares are held through a financial intermediary, contact your

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intermediary directly. Additionally, you may elect to enroll in eDelivery to receive electronic versions of these documents, as well as quarterly statements and supplements, by logging into your account at investor.columbiathreadneedleus.com.

Cash Flows

The timing and magnitude of cash inflows from investors buying Fund shares could prevent the Fund from always being fully invested. Conversely, the timing and magnitude of cash outflows to shareholders redeeming Fund shares could require the Fund to sell portfolio securities at less than opportune times or to hold ready reserves of uninvested cash in amounts larger than might otherwise be the case to meet shareholder redemptions. Either situation could adversely impact the Fund’s performance.

Understanding Annual Fund Operating Expenses

The Fund’s annual operating expenses, as presented in the Annual Fund Operating Expenses table in the Fees and Expenses of the Fund section of this prospectus, generally are based on expenses incurred during the Fund’s most recently completed fiscal year, may vary by share class and are expressed as a percentage (expense ratio) of the Fund’s average net assets during that fiscal year. The expense ratios reflect the Fund’s fee arrangements as of the date of this prospectus and, unless indicated otherwise, are based on expenses incurred during the Fund’s most recent fiscal year. The Fund’s assets will fluctuate, but unless indicated otherwise in the Annual Fund Operating Expenses table, no adjustments have been or will be made to the expense ratios to reflect any differences in the Fund’s average net assets between the most recently completed fiscal year and the date of this prospectus or a later date. In general, the Fund’s expense ratios will increase as its net assets decrease, such that the Fund’s actual expense ratios may be higher than the expense ratios presented in the Annual Fund Operating Expenses table if assets fall. As applicable, any commitment by the Investment Manager and/or its affiliates to waive fees and/or cap (reimburse) expenses is expected, in part, to limit the impact of any increase in the Fund’s expense ratios that would otherwise result because of a decrease in the Fund’s assets in the current fiscal year. The Fund’s annual operating expenses are comprised of (i) investment management fees, (ii) distribution and/or service fees, and (iii) other expenses. Management fees do not vary by class, but distribution and/or service fees and other expenses may vary by class.

Fee Waiver/Expense Reimbursement Arrangements and Impact on Past Performance

The Investment Manager and certain of its affiliates have contractually agreed to waive fees and/or reimburse expenses (excluding certain fees and expenses described below) through August 31, 2019, unless sooner terminated at the sole discretion of the Fund's Board, so that the Fund’s net operating expenses, after giving effect to fees waived/expenses reimbursed and any balance credits and/or overdraft charges from the Fund’s custodian, do not exceed the annual rates of:

Prospectus 2018

23

Columbia Bond Fund

More Information About the Fund (continued)

Columbia Bond Fund

More Information About the Fund (continued)

The Distributor

Shares of the Fund are distributed by Columbia Management Investment Distributors, Inc., which is located at 225 Franklin Street, Boston, MA 02110. The Distributor is a registered broker-dealer and an indirect, wholly-owned subsidiary of Ameriprise Financial. The Distributor and its affiliates may pay commissions, distribution and service fees and/or other compensation to entities, including Ameriprise Financial affiliates, for selling shares and providing services to investors.

The Transfer Agent

Columbia Management Investment Services Corp. is a registered transfer agent and wholly-owned subsidiary of Ameriprise Financial. The Transfer Agent is located at 225 Franklin Street, Boston, MA 02110, and its responsibilities include processing purchases, redemptions and exchanges of Fund shares, calculating and paying distributions, maintaining shareholder records, preparing account statements and providing customer service. The Transfer Agent has engaged DST Asset Manager Solutions, Inc. to provide various shareholder or “sub-transfer agency” services. In addition, the Transfer Agent enters into agreements with various financial intermediaries through which you may hold Fund shares, pursuant to which the Transfer Agent pays these financial intermediaries for providing certain shareholder services. Depending on the type of account, the Fund pays the Transfer Agent a per account fee or a fee based on the assets invested through omnibus accounts, and reimburses the Transfer Agent for certain out-of-pocket expenses, including certain payments to financial intermediaries through which shares are held.

Other Roles and Relationships of Ameriprise Financial and its Affiliates — Certain Conflicts of Interest

The Investment Manager, Distributor and Transfer Agent, all affiliates of Ameriprise Financial, provide various services to the Fund and other Columbia Funds for which they are compensated. Ameriprise Financial and its other affiliates may also provide other services to these funds and be compensated for them.

The Investment Manager and its affiliates may provide investment advisory and other services to other clients and customers substantially similar to those provided to the Columbia Funds. These activities, and other financial services activities of Ameriprise Financial and its affiliates, may present actual and potential conflicts of interest and introduce certain investment constraints.

Ameriprise Financial is a major financial services company, engaged in a broad range of financial activities beyond the mutual fund-related activities of the Investment Manager, including, among others, insurance, broker-dealer (sales and trading), asset management, banking and other financial activities. These additional activities may involve multiple advisory, financial, insurance and other interests in securities and other instruments, and in companies that issue securities and other instruments, that may be bought, sold or held by the Columbia Funds.

Conflicts of interest and limitations that could affect a Columbia Fund may arise from, for example, the following:

■	compensation and other benefits received by the Investment Manager and other Ameriprise Financial affiliates related to the management/administration of a Columbia Fund and the sale of its shares;

■	the allocation of, and competition for, investment opportunities among the Fund, other funds and accounts advised/managed by the Investment Manager and other Ameriprise Financial affiliates, or Ameriprise Financial itself and its affiliates;

■	separate and potentially divergent management of a Columbia Fund and other funds and accounts advised/managed by the Investment Manager and other Ameriprise Financial affiliates;

■	regulatory and other investment restrictions on investment activities of the Investment Manager and other Ameriprise Financial affiliates and accounts advised/managed by them;

■	insurance and other relationships of Ameriprise Financial affiliates with companies and other entities in which a Columbia Fund invests; and

■	regulatory and other restrictions relating to the sharing of information between Ameriprise Financial and its affiliates, including the Investment Manager, and a Columbia Fund.

26	Prospectus 2018

Columbia Bond Fund

More Information About the Fund (continued)

The Investment Manager and Ameriprise Financial have adopted various policies and procedures that are intended to identify, monitor and address conflicts of interest. However, there is no assurance that these policies, procedures and disclosures will be effective.

Additional information about Ameriprise Financial and the types of conflicts of interest and other matters referenced above is set forth in the Investment Management and Other Services — Other Roles and Relationships of Ameriprise Financial and its Affiliates — Certain Conflicts of Interest section of the SAI. Investors in the Columbia Funds should carefully review these disclosures and consult with their financial advisor if they have any questions.

Certain Legal Matters

Ameriprise Financial and certain of its affiliates have historically been involved in a number of legal, arbitration and regulatory proceedings, including routine litigation, class actions and governmental actions, concerning matters arising in connection with the conduct of their business activities. Ameriprise Financial believes that the Fund is not currently the subject of, and that neither Ameriprise Financial nor any of its affiliates are the subject of, any pending legal, arbitration or regulatory proceedings that are likely to have a material adverse effect on the Fund or the ability of Ameriprise Financial or its affiliates to perform under their contracts with the Fund. Information regarding certain pending and settled legal proceedings may be found in the Fund’s shareholder reports and in the SAI. Additionally, Ameriprise Financial is required to make quarterly (10-Q), annual (10-K) and, as necessary, 8-K filings with the SEC on legal and regulatory matters that relate to Ameriprise Financial and its affiliates. Copies of these filings may be obtained by accessing the SEC website at sec.gov.

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27

Columbia Bond Fund

Choosing a Share Class

The Funds

The Columbia Funds (referred to as the Funds) generally share the same policies and procedures for investor services, as described below. Each Fund is a series of Columbia Funds Series Trust (CFST), Columbia Funds Series Trust I (CFST I) or Columbia Funds Series Trust II (CFST II), and certain features of distribution and/or service plans may differ among these trusts. The Fund offered by this prospectus is a series of CFST I. Columbia Funds with names that include the words “Tax-Exempt,” “Municipal” or “Muni” (the Tax-Exempt Funds) have certain policies that differ from other Columbia Funds (the Taxable Funds). The Fund offered by this prospectus is treated as a Taxable Fund for these purposes.

Funds Contact Information

Additional information about the Funds, including sales charges and other class features and policies, can be obtained, free of charge, at columbiathreadneedleus.com,* by calling toll-free 800.345.6611, or by writing (regular mail) to Columbia Management Investment Services Corp., P.O. Box 8081, Boston, MA 02266-8081 or (express mail) Columbia Management Investment Services Corp., c/o DST Asset Manager Solutions, Inc., 30 Dan Road, Suite 8081, Canton, MA 02021-2809. Please note, effective November 1, 2018, the Fund’s regular mail address is changed to Columbia Management Investment Services Corp., P.O. Box 219104, Kansas City, MO 64121-9104, and the Fund’s express mail address is changed to Columbia Management Investment Services Corp., c/o DST Asset Manager Solutions, Inc., 430 W 7 ^th Street, Ste 219104, Kansas City, MO 64105-1407.**

*	The website references in this prospectus are inactive links and information contained in or otherwise accessible through the referenced websites does not form a part of this prospectus.

**

Based on the date noted above, mail received at an incorrect address will be forwarded to the correct address, and will not be processed until received, in “good form,” at the correct address. This may affect the trade date you receive for transaction requests, which may negatively impact the value of your purchase or sale.

28	Prospectus 2018

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Choosing a Share Class (continued)

Summary of Share Class Features

Each share class has its own investment eligibility criteria, cost structure and other features. You may not be eligible to invest in every share class. Your financial intermediary may not make every share class available or may cease to make available one or more share classes of the Fund. The share class you select through your financial intermediary may have higher fees and/or sales charges than other classes of shares available through other financial intermediaries. An investor transacting in a class of Fund shares without any front-end sales charge, contingent deferred sales charge (CDSC), or other asset-based fee for sales or distribution, such as a Rule 12b-1 fee, may be required to pay a commission to the financial intermediary for effecting such transactions. Each investor’s personal situation is different and you may wish to discuss with your financial intermediary the share classes the Fund offers, which share classes are available to you and which share class(es) is/are appropriate for you. In all instances, it is your responsibility to notify your financial intermediary or (for Direct-at-Fund Accounts, as defined below) the Fund at the time of purchase of any relationship or other facts that may qualify you for sales charge waivers or discounts. The Fund, the Distributor and the Transfer Agent do not provide investment advice or make recommendations regarding Fund share classes. Your financial intermediary may provide advice and recommendations to you, such as which share class(es) is/are appropriate for you.

When deciding which class of shares to buy, you should consider, among other things:

■	The amount you plan to invest.

■	How long you intend to remain invested in the Fund.

■	The fees (e.g., sales charge or “load”) and expenses for each share class.

■	Whether you may be eligible for a reduction or waiver of sales charges when you buy or sell shares.

■	The net asset value (NAV) per share is the price of a share calculated by the Fund every business day.
■	The offering price per share is the NAV per share plus any front-end sales charge (or load) that applies.

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Columbia Bond Fund

Choosing a Share Class (continued)

Share Class Features

The following summarizes the primary features of Class A, Class Adv, Class C, Class Inst, Class Inst2, Class Inst3, Class R, Class T and Class V shares.

Not all Funds offer every class of shares. The Fund offers the class(es) of shares set forth on the cover of this prospectus and may offer other share classes through a separate prospectus. Although certain share classes are generally closed to new and/or existing investors, information relating to these share classes is included in the table below because certain qualifying purchase orders are permitted, as described below.

The sales charge reductions and waivers available to investors who purchase and hold their Fund shares through different financial intermediaries may vary. Appendix A describes financial intermediary-specific reductions and/or waiver policies. A shareholder transacting in Fund shares through a financial intermediary identified in Appendix A should carefully read the terms and conditions of Appendix A . A reduction and/or waiver that is specific to a particular financial intermediary is not available to Direct-at-Fund Accounts, as defined below, or through another financial intermediary. The information in Appendix A may be provided by, or compiled from or based on information provided by the financial intermediaries identified in Appendix A . The Fund, the Investment Manager and the Distributor do not establish financial intermediary-specific policies and are not responsible for ensuring that you receive any discounts or waivers that may be available to you in this regard. Please consult your financial intermediary with respect to any sales charge reduction and/or waiver described in Appendix A .

A Note About Class T Shares

Class T shares are sold only through financial intermediaries that, by written agreement with the Distributor, are specifically authorized to sell Class T shares (Class T Intermediaries).

Class T shares are capable of being offered by different financial intermediaries with different front-end sales charge structures. Currently, Class T shares are offered with only one sales charge structure, which means that all Class T Intermediaries that are offering Class T shares are doing so with the same pricing. For convenience, these Class T Intermediaries are referred to as Category One Financial Intermediaries . Financial intermediaries may in the future seek to offer Class T shares under a different pricing structure and, as such, other categories of Class T Intermediaries may be added in the future. Note also that, unlike other classes of shares of the Fund with a front-end sales charge (i.e., Class A and Class V shares, as available), the front-end sales charge applicable to Class T shares is a per-transaction charge, meaning that separate orders will not be aggregated for purposes of calculating the rate of the sales charge payable. Discounts are not available for Class T shares (for example, under a right of accumulation, letter of intent or other such programs).

    

30	Prospectus 2018

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Choosing a Share Class (continued)

(g)	If you are eligible to invest in Class A shares without a front-end sales charge, you should discuss your options with your financial intermediary. For more information, see Choosing a Share Class – Reductions/Waivers of Sales Charges.

(h)	There is no CDSC on redemptions from Class C shares of Columbia Government Money Market Fund.

(i)	These share classes are closed to new accounts, or closed to previously eligible investors, subject to certain conditions, as summarized below and described in more detail under Buying, Selling and Exchanging Shares — Buying Shares — Eligible Investors:

•   Class Inst Shares . Financial intermediaries that clear Fund share transactions through designated financial intermediaries and their mutual fund trading platforms that have been given specific written notice from the Transfer Agent, effective March 29, 2013, of the termination of their eligibility for new purchases of Class Inst shares and omnibus retirement plans are not permitted to establish new Class Inst accounts, subject to certain exceptions. Omnibus retirement plans that opened and, subject to exceptions, funded a Class Inst account as of close of business on March 28, 2013, and have continuously held Class Inst shares in such account after such date, may generally continue to make additional purchases of Class Inst shares, open new Class Inst accounts and add new participants. In certain circumstances and in the sole discretion of the Distributor, omnibus retirement plans affiliated with a grandfathered plan may also open new Class Inst accounts. Accounts of financial intermediaries (other than omnibus retirement plans) that clear Fund share transactions for their client or customer accounts through designated financial intermediaries and their mutual fund trading platforms are not permitted to establish new Class Inst accounts or make additional purchases of Class Inst shares (other than through Fund distribution reinvestments).

•   Class Inst2 Shares . Shareholders with Class Inst2 accounts funded before November 8, 2012 who do not satisfy the current eligibility criteria for Class Inst2 shares may not establish new Class Inst2 accounts but may continue to make additional purchases of Class Inst2 shares in existing accounts. In addition, investment advisory programs and similar programs that opened a Class Inst2 account as of May 1, 2010, and continuously hold Class Inst2 shares in such account after such date, may generally not only continue to make additional purchases of Class Inst2 shares but also open new Class Inst2 accounts and add new shareholders in the program.

•   Class Inst3 Shares . Shareholders with Class Inst3 accounts funded before November 8, 2012 who do not satisfy the current eligibility criteria for Class Inst3 shares may not establish new accounts for such share class but may continue to make additional purchases of Class Inst3 shares in existing accounts.

•   Class V Shares. Shareholders   with Class V accounts who received, and have continuously held, Class V shares (formerly named Class T shares, which have no relation to the Fund’s current Class T shares) in connection with the merger of certain Galaxy funds into certain Funds that were then named Liberty funds may continue to make additional purchases of such share class.

Sales Charges and Commissions

Sales charges, commissions, and distribution fees compensate financial intermediaries (typically your financial advisor) for selling shares to you, and service fees compensate financial intermediaries for maintaining and servicing the shares held in your account with them. Distribution and service fees are discussed in a separate sub-section below. Depending on which share class you choose and the financial intermediary through which you purchase your shares, you may pay these charges at potentially different levels at the outset as a front-end sales charge, at the time you sell your shares as a CDSC and/or over time in the form of distribution and/or service fees.

As described in more detail below, Class A, Class T and Class V shares have a front-end sales charge, which is deducted from your purchase price when you buy your shares, and results in a smaller dollar amount being invested in the Fund than the purchase price you pay (unless you qualify for a waiver or (Class A shares and Class V shares only) reduction of the sales charge). The Fund’s other share classes do not have a front-end sales charge, so the full amount of your purchase price is invested in those classes. Class A shares have lower ongoing distribution and/or service fees than Class C and Class R shares of the Fund. Over time, Class C and Class R shares can incur distribution and/or service fees that are equal to or more than the front-end sales charge and the distribution and/or service fees you would pay for Class A shares. Although the full amount of your purchase price of Class C and Class R shares is invested in a Fund, your return on this money will be reduced by the expected higher annual expenses of Class C and Class R shares. In this regard, note that effective July 1, 2018, Class C shares will automatically convert to Class A shares of the same Fund in the month of or the month following the 10-year anniversary of the Class C shares purchase date. No sales charge or other charges will apply in connection with this automatic conversion, and conversions are free from U.S. federal income tax. Once your Class C shares automatically convert to Class A shares, your total returns from an investment in the Fund may increase as a result of the lower operating costs of Class A shares. Class Adv, Class Inst, Class Inst2 and Class Inst3 shares of the Fund do not have distribution and/or service fees.

Whether the ultimate cost is higher for one share class over another depends on the amount you invest, how long you hold your shares, the fees (i.e., sales charges) and expenses of the class and whether you are eligible for reduced or waived sales charges, if available. The differential between classes also will vary depending on the actual investment return for any given investment period. You are responsible for choosing the share class most appropriate for you after taking into account your share class eligibility, class-specific features, and any applicable reductions in, or

36	Prospectus 2018

Columbia Bond Fund

Choosing a Share Class (continued)

waivers of, sales charges. For more information, see Choosing a Share Class – Reductions/Waivers of Sales Charges . We encourage you to consult with a financial advisor who can help you with your investment decisions. Please contact your financial intermediary for more information about services, fees and expenses, and other important information about investing in the Fund, as well as with any questions you may have about your investing options. In all instances, it is your responsibility to notify your financial intermediary or (for Direct-at-Fund Accounts, as defined below) the Fund at the time of purchase of any relationship or other facts that may qualify you for sales charge waivers or discounts.

Class A Shares — Front-End Sales Charge

Unless your purchase qualifies for a waiver (e.g., you buy the shares through reinvested Fund distributions or subject to an applicable financial intermediary-specific waiver), you will pay a front-end sales charge when you buy Class A shares (other than shares of Columbia Government Money Market Fund, Columbia Large Cap Enhanced Core Fund, Columbia Large Cap Index Fund, Columbia Mid Cap Index Fund, Columbia Small Cap Index Fund and Columbia U.S. Treasury Index Fund), resulting in a smaller dollar amount being invested in a Fund than the purchase price you pay. Effective July 1, 2018, Class C shares automatically convert to Class A shares of the same Fund in the month of or the month following the 10-year anniversary of the Class C shares purchase date. Under this policy, the Class A shares sales charge is waived on Class C shares automatically converted to Class A shares. For more information about sales charge waivers and reduction opportunities, see Choosing a Share Class — Reductions/Waivers of Sales Charges and Appendix A.

The Distributor receives the sales charge and re-allows (or pays) a portion of the sales charge to the financial intermediary through which you purchased the shares. The Distributor retains the balance of the sales charge. The Distributor retains the full sales charge you pay when you purchase shares of the Fund directly from the Fund (through the Transfer Agent, rather than through a financial intermediary).

The front-end sales charge you will pay on Class A shares:

■	depends on the amount you are investing (generally, the larger the investment, the smaller the percentage sales charge), and

■	is based on the total amount of your purchase and the value of your account (and any other accounts eligible for aggregation of which you or your financial intermediary notifies the Fund).

The table below presents the front-end sales charge as a percentage of both the offering price and the net amount invested.

    

Class A Shares — Front-End Sales Charge — Breakpoint Schedule*
Breakpoint Schedule For:	Dollar amount of shares bought (a)	Sales charge as a % of the offering price (b)	Sales charge as a % of the net amount invested (b)	Amount retained by or paid to financial intermediaries as a % of the offering price
Equity Funds, Columbia Adaptive Risk Allocation Fund, Columbia Alternative Beta Fund, Columbia Commodity Strategy Fund, Columbia Diversified Absolute Return Fund and Funds-of-Funds (equity)*	$ 0–$49,999	5.75%	6.10%	5.00%
	$ 50,000–$99,999	4.50%	4.71%	3.75%
	$100,000–$249,999	3.50%	3.63%	3.00%
	$250,000–$499,999	2.50%	2.56%	2.15%
	$500,000–$999,999	2.00%	2.04%	1.75%
	$ 1,000,000 or more	0.00%	0.00%	0.00% (c)

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37

Columbia Bond Fund

Choosing a Share Class (continued)

Class A Shares — CDSC

In some cases, you'll pay a CDSC if you sell Class A shares that you purchased without a front-end sales charge.

Tax-Exempt Funds

■

If you purchased Class A shares of any Tax-Exempt Fund (other than Columbia Short Term Municipal Bond Fund and Columbia U.S. Social Bond Fund) without paying a front-end sales charge because your eligible accounts aggregated $500,000 or more at the time of purchase, you will incur a CDSC of 0.75% if you redeem those shares within 12 months after purchase. Subsequent Class A share purchases that bring your aggregate account value to $500,000 or more will also be subject to a CDSC of 0.75% if you redeem those shares within 12 months after purchase.

■

If you purchased Class A shares of Columbia Short Term Municipal Bond Fund without paying a front-end sales charge because your eligible accounts aggregated $500,000 or more at the time of purchase, you will incur a CDSC of 0.50% if you redeem those shares within 12 months after purchase. Subsequent Class A share purchases that bring your aggregate account value to $500,000 or more will also be subject to a CDSC of 0.50% if you redeem those shares within 12 months after purchase.

■

If you purchased Class A shares of Columbia U.S. Social Bond Fund without paying a front-end sales charge because your eligible accounts aggregated $500,000 or more at the time of purchase, you will incur a CDSC of 0.75% if you redeem those shares within 12 months after purchase. Subsequent Class A share purchases that bring your aggregate account value to $500,000 or more will also be subject to a CDSC of 0.75% if you redeem those shares within 12 months after purchase.

Taxable Funds

■

If you purchased Class A shares of any Taxable Fund without paying a front-end sales charge because your eligible accounts aggregated between $1 million and $50 million at the time of purchase, you will incur a CDSC if you redeem those shares within 18 months after purchase, which is charged as follows: 1.00% CDSC if shares are redeemed within 12 months after purchase; and 0.50% CDSC if shares are redeemed more than 12, but less than 18, months after purchase. Subsequent Class A share purchases that bring your aggregate account value to $1 million or more (but less than $50 million) will also be subject to a CDSC if you redeem them within 18 months after purchase as described in the previous sentence.

*	The commission level applies to the applicable asset level; therefore, for example, for a purchase of $5 million, the Distributor would pay a commission of 0.75% on the first $3,999,999 and 0.50% on the balance.

**	The commission level on purchases of Class A shares of Columbia Short Term Municipal Bond Fund is: 0.50% on purchases of $500,000 to $19,999,999 and 0.25% on purchases of $20 million or more.

    

Prospectus 2018

39

Columbia Bond Fund

Choosing a Share Class (continued)

Class C Shares — CDSC

You will pay a CDSC of 1.00% if you redeem Class C shares within 12 months of buying them unless you qualify for a waiver of the CDSC (e.g., the shares you are selling were purchased with reinvested Fund distributions). Redemptions of Class C shares are not subject to a CDSC if redeemed after 12 months. Class C shares of Columbia Government Money Market Fund are not subject to a CDSC. For more information, see Choosing a Share Class — Reductions/Waivers of Sales Charges .

Class C Shares — Commissions

Although there is no front-end sales charge when you buy Class C shares, the Distributor makes an up-front payment (which includes a sales commission and an advance of service fees) directly to your financial intermediary of up to 1.00% of the NAV per share when you buy Class C shares (except on purchases of Class C shares of Columbia Government Money Market Fund). A portion of this payment may be passed along to your financial advisor. The Distributor seeks to recover this payment through fees it receives under the Fund's distribution and/or service plan during the first 12 months following the sale of Class C shares, and any applicable CDSC when you sell your shares. For more information, see Choosing a Share Class — Distribution and Service Fees.

Class T Shares — Front-End Sales Charge

Different financial intermediaries may offer Class T shares with different front-end sales charge structures. This differs from other Fund share classes, which have fixed sales charge structures. As of the date of this prospectus, Class T shares are offered with only one sales charge structure, which means that all financial intermediaries that are offering Class T shares (Class T Intermediaries) are offering the same pricing. For convenience, these Class T Intermediaries are referred to as Category One Financial Intermediaries. Financial intermediaries may seek to offer Class T shares under a different pricing structure and, as a result, other categories of Class T Intermediaries may be added in the future.

The front-end sales charge applicable to Class T shares is a per-transaction charge, meaning that the separate orders will not be aggregated for purposes of calculating the rate of the sales charge payable, which is different from other Fund share classes with a front-end sales charge. Unless your purchase qualifies for a waiver, you will pay a front-end sales charge on each purchase of Class T shares based on the amount of each purchase transaction. As with all front-end sales charges, this will result in a smaller dollar amount being invested in the Fund than the purchase price you pay. No discounts (for example, under a right of accumulation, letter of intent, or other such programs) are available for Class T shares. For information about sales charge waivers, see Choosing a Share Class — Reductions/Waivers — Class T Sales Charge Waivers below.

    

Class T Shares — Front-End Sales Charge (Per Transaction)
Breakpoint Schedule For:	Dollar amount of shares bought	Sales charge as a % of the offering price (a)	Sales charge as a % of the net amount invested (a)	Amount retained by or paid to Financial Intermediaries as a % of the offering price
Class T Shares (Purchasing through a Category One Financial Intermediary)	$ 0–$249,999	2.50%	2.56%	2.50%
	$250,000–$499,999	2.00%	2.04%	2.00%
	$500,000–$999,999	1.50%	1.53%	1.50%
	$ 1,000,000 or more	1.00%	1.01%	1.00%

(a)

Because the offering price is calculated to two decimal places, the dollar amount of the sales charge as a percentage of the offering price and your net amount invested for any particular purchase of Fund shares may be higher or lower depending on whether downward or upward rounding was required during the calculation process. Purchase price includes the sales charge.

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Columbia Bond Fund

Choosing a Share Class (continued)

Class V Shares — Front-End Sales Charge

Unless you qualify for a waiver (e.g., you purchase shares through reinvested Fund distributions), you will pay a front-end sales charge when you buy Class V shares, resulting in a smaller dollar amount being invested in a Fund than the purchase price you pay. For more information about sales charge waivers (as well as sales charge reduction opportunities), see Choosing a Share Class — Reductions/Waivers of Sales Charges.

The front-end sales charge you will pay on Class V shares:

■	depends on the amount you are investing (generally, the larger the investment, the smaller the percentage sales charge), and

■	is based on the total amount of your purchase and the value of your account (and any other accounts eligible for aggregation of which you notify your financial intermediary or, in the case of Direct-at-Fund Accounts (as defined below), you notify the Fund).

    

Class V Shares — Front-End Sales Charge — Breakpoint Schedule
Breakpoint Schedule For:	Dollar amount of shares bought (a)	Sales charge as a % of the offering price (b)	Sales charge as a % of the net amount invested (b)	Amount retained by or paid to Financial Intermediaries as a % of the offering price
Equity Funds	$ 0–$49,999	5.75%	6.10%	5.00%
	$ 50,000–$99,999	4.50%	4.71%	3.75%
	$100,000–$249,999	3.50%	3.63%	2.75%
	$250,000–$499,999	2.50%	2.56%	2.00%
	$500,000–$999,999	2.00%	2.04%	1.75%
	$ 1,000,000 or more	0.00%	0.00%	0.00% (c)
Fixed Income Funds	$ 0–$49,999	4.75%	4.99%	4.25%
	$ 50,000–$99,999	4.50%	4.71%	3.75%
	$100,000–$249,999	3.50%	3.63%	2.75%
	$250,000–$499,999	2.50%	2.56%	2.00%
	$500,000–$999,999	2.00%	2.04%	1.75%
	$ 1,000,000 or more	0.00%	0.00%	0.00% (c)

(a)	Purchase amounts and account values are aggregated among all eligible Fund accounts for the purposes of this table.

(b)

Because the offering price is calculated to two decimal places, the dollar amount of the sales charge as a percentage of the offering price and your net amount invested for any particular purchase of Fund shares may be higher or lower depending on whether downward or upward rounding was required during the calculation process.

(c)	For more information regarding cumulative commissions paid to your financial intermediary when you buy $1 million or more of Class V shares, see Class V Shares — Commissions below.

Class V Shares — CDSC

In some cases, you will pay a CDSC if you sell Class V shares that you bought without a front-end sales charge.

■

If you purchased Class V shares without a front-end sales charge because your eligible accounts aggregated between $1 million and $50 million at the time of purchase, you will incur a CDSC if you redeem those shares within 18 months after purchase, which is charged as follows: 1.00% CDSC if shares are redeemed within 12 months after purchase, and 0.50% CDSC if shares are redeemed more than 12, but less than 18, months after purchase.

■	Subsequent Class V share purchases that bring your aggregate account value to $1 million or more (but less than $50 million) will also be subject to a CDSC if you redeem them within the time periods noted above.

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Choosing a Share Class (continued)

reinstatement privilege do not count as purchases made under an LOI. For purposes of making an LOI to purchase additional shares, you may aggregate eligible shares owned by you or your immediate family members in eligible accounts, valued as of the day immediately before the initiation of your LOI.

You must request the reduced sales charge (whether through ROA or an LOI) when you buy shares. If you do not complete and file an LOI, or do not request the reduced sales charge at the time of purchase, you will not be eligible for the reduced sales charge. To obtain a breakpoint discount, you must notify your financial intermediary in writing at the time you buy your shares of each eligible account maintained by you and members of your immediate family, including accounts maintained through different financial intermediaries. You and your financial intermediary are responsible for ensuring that you receive discounts for which you are eligible. The Fund is not responsible for a financial intermediary's failure to apply the eligible discount to your account. You may be asked by your financial intermediary (or by the Fund if you hold your account directly with the Fund) for account statements or other records to verify your discount eligibility for new and subsequent purchases, including, when applicable, records for accounts opened with a different financial intermediary and records of accounts established by members of your immediate family.

The sales charge reductions available to investors who purchase and hold their Fund shares through different financial intermediaries may vary. For a description of such financial intermediary-specific sales charge reductions, see Appendix A .

Eligible Accounts

The following accounts are eligible for account value aggregation as described above, provided that they are invested in Class A (excluding, in the case of Direct-at-Fund Accounts, Funds that do not assess a front-end sales charge, including Columbia Government Money Market Fund, Columbia Large Cap Enhanced Core Fund, Columbia Large Cap Index Fund, Columbia Mid Cap Index Fund, Columbia Small Cap Index Fund and Columbia U.S. Treasury Index Fund, unless such shares were purchased via an exchange from Class A shares of a Fund on which you paid the Class A share applicable front-end sales charge), Class C, Class E, Class Inst or Class V shares of a Fund, or non-retirement plan accounts invested in Class Adv or Class Inst2 shares of a Fund: individual or joint accounts; Roth and traditional Individual Retirement Accounts (IRAs); Simplified Employee Pension accounts (SEPs), Savings Investment Match Plans for Employees of Small Employers accounts (SIMPLEs) and Tax Sheltered Custodial Accounts (TSCAs); Uniform Gifts to Minors Act (UGMA)/Uniform Transfers to Minors Act (UTMA) accounts for which you, your spouse, or your domestic partner is parent or guardian of the minor child; revocable trust accounts for which you or an immediate family member, individually, is the beneficial owner/grantor; accounts held in the name of your, your spouse’s, or your domestic partner’s sole proprietorship or single owner limited liability company or S corporation; qualified retirement plan assets, provided that you are the sole owner of the business sponsoring the plan, are the sole participant (other than a spouse) in the plan, and have no intention of adding participants to the plan; and investments in wrap accounts.

The following accounts are not eligible for account value aggregation as described above: accounts of pension and retirement plans with multiple participants, such as 401(k) plans (which are combined to reduce the sales charge for the entire pension or retirement plan and therefore are not used to reduce the sales charge for your individual

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Choosing a Share Class (continued)

accounts); investments in 529 plans, donor advised funds, variable annuities, variable insurance products or managed separate accounts; charitable and irrevocable trust accounts; accounts holding shares of money market funds that used the Columbia brand before May 1, 2010; accounts invested in Class Inst3, Class R or Class T shares of a Fund; and retirement plan accounts invested in Class Adv or Class Inst2 shares of a Fund.

Additionally, direct purchases of shares of Columbia Government Money Market Fund may not be aggregated for account value aggregation purposes; however, shares of Columbia Government Money Market Fund acquired by exchange from other Columbia Funds that assess a sales charge may be included in account value aggregation.

Class A and Class V Shares Front-End Sales Charge Waivers

There are no front-end sales charges on reinvested Fund distributions. Effective July 1, 2018, Class C shares automatically convert to Class A shares of the same Fund in the month of or the month following the 10-year anniversary of the Class C shares purchase date. Under this policy, the Class A shares sales charge is waived on Class C shares automatically converted to Class A shares. The Distributor may waive front-end sales charges on purchases of Class A and Class V shares of the Funds by certain categories of investors, including Board members, certain employees of financial intermediaries, Fund portfolio managers, certain partners and employees of outside legal counsel to the funds or the Board, separate accounts of an insurance company exempt from registration as an investment company under Section 3(c)(11) of the 1940 Act, registered broker-dealer firms that have an agreement with the Distributor purchasing fund shares for their investment account only, and qualified employee benefit plan rollovers to Class A shares in the same Fund (see Appendix S to the SAI for details). For a more complete description of categories of investors who may purchase Class A and Class V shares of the Funds at NAV, without payment of any front-end sales charge that would otherwise apply, see Appendix S to the SAI.

In addition, certain types of purchases of Class A and Class V shares may be made at NAV. The Distributor may waive front-end sales charges on (i) purchases (including exchanges) of Class A shares in accounts of financial intermediaries that have entered into agreements with the Distributor to offer Fund shares to self-directed investment brokerage accounts that may or may not charge a transaction fee to customers; (ii) exchanges of Class Inst shares of a Fund for Class A shares of the Fund; (iii) purchases of Class A shares on brokerage mutual fund-only platforms of financial intermediaries that have an agreement with the Distributor that specifically authorizes the offering of Class A shares within such platform; (iv) purchases through certain wrap fee or other products or programs that involve fee-based compensation arrangements that have, or clear trades through a financial intermediary that has, a selling agreement with the Distributor; (v) purchases through state sponsored 529 Plans; (vi) purchases through banks, trust companies, and thrift institutions acting as fiduciaries; and (vii) purchases through certain employee benefit plans and certain qualified deferred compensation plans. For a more complete description of these eligible transactions, see Appendix S to the SAI.

The sales charge waivers available to investors who purchase and hold their Fund shares through different financial intermediaries may vary. For a description of such financial intermediary-specific sales charge waivers, see Appendix A .

Class T Sales Charge Waivers

There is no front-end sales charge on (i) reinvested Fund distributions; (ii) exchanges of Class T shares of the Fund from, at the discretion of Class T Intermediaries, another class of shares of the same Fund held in accounts of Class T Intermediaries, provided that (a) the other share class may only be exchanged for Class T shares if your financial intermediary does not offer that other share class on the financial intermediary’s commission-based platform and (b), unless waived in the Distributor’s discretion, shares of the class to be exchanged are held in a networked or omnibus account with the Fund; and (iii) purchases within fee-based accounts, provided that the Class T Intermediary has an agreement with the Distributor that specifically contemplates offering Class T shares within the designated fee-based platform.

The sales charge waivers available to investors who purchase and hold their Fund shares through different financial intermediaries may vary. For a description of such financial intermediary-specific sales charge waivers, see Appendix A .

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Columbia Bond Fund

Choosing a Share Class (continued)

CDSC Waivers – Class A, Class C and Class V

You may be able to avoid an otherwise applicable CDSC when you sell Class A, Class C or Class V shares of the Fund. This could happen because of the way in which you originally invested in the Fund, because of your relationship with the Funds or for other reasons. For example, the CDSC will be waived on redemptions of shares in the event of the shareholder's death; that result from required minimum distributions taken from retirement accounts when the shareholder reaches age 70½; in connection with the Fund's Small Account Policy (which is described in Buying, Selling and Exchanging Shares — Transaction Rules and Policies ); and by certain other investors and in certain other types of transactions or situations. For a more complete description of the available waivers of the CDSC on redemptions of Class A, Class C or Class V shares, see Appendix S to the SAI.

The sales charge waivers available to investors who purchase and hold their Fund shares through different financial intermediaries may vary. For a description of such financial intermediary-specific sales charge waivers, see Appendix A .

Repurchases (Reinstatements)

As noted in the table below, you can redeem shares of certain classes (see Redeemed Share Class below) and use such redemption proceeds to buy shares of the Corresponding Repurchase Class without paying an otherwise applicable sales charge and/or CDSC (other than, in the case of Direct-at-Fund Accounts, redemptions from Funds that do not assess a front-end sales charge, including Columbia Government Money Market Fund, Columbia Large Cap Enhanced Core Fund, Columbia Large Cap Index Fund, Columbia Mid Cap Index Fund, Columbia Small Cap Index Fund and Columbia U.S. Treasury Index Fund, unless such shares were purchased via an exchange from Class A shares of a Fund on which you paid the Class A share applicable front-end sales charge) within 90 days, up to the amount of the redemption proceeds.

    

Any CDSC paid upon redemption of your Class A, Class C or Class V shares of a Fund will not be reimbursed.

To be eligible for the repurchase (or reinstatement) privilege, the purchase must be made into an account for the same owner, but does not need to be into the same Fund from which the shares were sold. The Transfer Agent, Distributor or their agents must receive a written reinstatement request from you or your financial intermediary within 90 days after the shares are redeemed. The purchase of the Corresponding Repurchase Class (as noted in the table above) through this repurchase (or reinstatement) privilege will be made at the NAV of such shares next calculated after the request is received in “good form.” Systematic withdrawals and purchases are excluded from this policy.

Restrictions and Changes in Terms and Conditions

Restrictions may apply to certain accounts and certain transactions. The Funds and/or the Distributor may change or cancel these terms and conditions at any time. Unless you provide your financial intermediary with information in writing about all of the factors that may count toward available reductions or waivers of an applicable sales charge, there can be no assurance that you will receive all of the reductions and waivers for which you may be eligible. To the extent your Fund account is held directly with the Fund, you should provide this information to the Fund when placing your purchase or redemption order. Please see Appendix A to this prospectus and Appendix S of the SAI for more information about sales charge waivers.

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Columbia Bond Fund

Choosing a Share Class (continued)

Funds	Maximum Class A Distribution Fee	Maximum Class A Service Fee	Maximum Class A Combined Total
Columbia Adaptive Risk Allocation Fund, Columbia Alternative Beta Fund, Columbia AMT-Free Connecticut Intermediate Muni Bond Fund, Columbia AMT-Free Massachusetts Intermediate Muni Bond Fund, Columbia AMT-Free New York Intermediate Muni Bond Fund, Columbia Bond Fund, Columbia Corporate Income Fund, Columbia Diversified Absolute Return Fund, Columbia Diversified Real Return Fund, Columbia Emerging Markets Fund, Columbia Global Dividend Opportunity Fund, Columbia Global Energy and Natural Resources Fund, Columbia Greater China Fund, Columbia Multi-Asset Income Fund, Columbia Pacific/Asia Fund, Columbia Select Large Cap Growth Fund, Columbia Small Cap Value Fund I, Columbia Strategic California Municipal Income Fund, Columbia Strategic Income Fund, Columbia Strategic New York Municipal Income Fund, Columbia U.S. Social Bond Fund, Columbia U.S. Treasury Index Fund	—	0.25%	0.25%
Columbia AMT-Free Intermediate Muni Bond Fund, Columbia High Yield Municipal Fund, Columbia Tax-Exempt Fund	—	0.20%	0.20%

(b)

The service fees for Class A and Class C shares of certain Funds vary. The annual service fee for Class A and Class C shares of Columbia AMT-Free Intermediate Muni Bond Fund, Columbia High Yield Municipal Fund and Columbia Tax-Exempt Fund may equal up to 0.20% of the average daily NAV of all shares of such Fund class. The annual distribution fee for Class C shares for Columbia AMT-Free Intermediate Muni Bond Fund shall be 0.65% of the average daily net assets of the Fund's Class C shares. The Distributor has voluntarily agreed to waive the service fee for Class A and Class C shares of Columbia U.S. Treasury Index Fund so that the service fee does not exceed 0.15% annually. This arrangement may be modified or terminated by the Distributor at any time.

(c)

Fee amounts noted apply to all Funds other than Columbia Government Money Market Fund, which, for each of Class A and Class T shares, pays distribution and service fees of 0.10%, and for Class C shares pays distribution fees of 0.75%. The Distributor has currently agreed not to be reimbursed by the Fund for 0.25% of the 0.50% fee for Class R shares of Columbia Government Money Market Fund. The Distributor has voluntarily agreed to waive the Rule 12b-1 fees it receives from Class A, Class C, Class R and Class T shares of Columbia Government Money Market Fund. This arrangement may be modified or terminated by the Distributor at any time. Compensation paid to financial intermediaries may be suspended to the extent of the Distributor's waiver of the Rule 12b-1 fees on these specific share classes of these Funds.

(d)

The Distributor has voluntarily agreed to waive a portion of the distribution fee for Class C shares of the following Funds so that the distribution fee does not exceed the specified percentage annually: 0.45% for Columbia AMT-Free Connecticut Intermediate Muni Bond Fund, Columbia AMT-Free Massachusetts Intermediate Muni Bond Fund, Columbia AMT-Free New York Intermediate Muni Bond Fund, Columbia AMT-Free Oregon Intermediate Muni Bond Fund, Columbia Strategic California Municipal Income Fund and Columbia Strategic New York Municipal Income Fund; 0.60% for Columbia Corporate Income Fund and Columbia Short Term Bond Fund; 0.65% for Columbia High Yield Municipal Fund and Columbia Tax-Exempt Fund; and 0.70% for Columbia U.S. Treasury Index Fund. These arrangements may be modified or terminated by the Distributor at any time.

(e)

Class R shares of series of CFST and CFST I pay a distribution fee pursuant to a Rule 12b-1 plan for Class R shares. The Funds do not have a shareholder service plan for Class R shares. Series of CFST II have a distribution and shareholder service plan for Class R shares, which, prior to the close of business on September 3, 2010, were known as Class R2 shares. For Class R shares of series of CFST II, the maximum fee under the plan reimbursed for distribution expenses is equal on an annual basis to 0.50% of the average daily net assets of the Fund attributable to Class R shares. Of that amount, up to 0.25% may be reimbursed for shareholder service expenses.

(f)	The combined distribution fee and service fee for Class T shares of series of CFST and CFST I shall not exceed 0.25%. Class T shares of series of CFST II pay a combined distribution and service fee of 0.25%.

(g)

The shareholder servicing fees for Class V shares are up to 0.50% of average daily net assets attributable to Class V shares for equity Funds and 0.40% for fixed income Funds. In general, the Funds currently limit such fees to a maximum of 0.25% for equity Funds and 0.15% for fixed-income Funds. These fees for Class V shares are not paid pursuant to a Rule 12b-1 plan. See Class V Shareholder Service Fees below for more information.

The distribution and/or service fees for Class A, Class C, Class R and Class T shares, as applicable, are subject to the requirements of Rule 12b-1 under the 1940 Act. The Distributor may retain these fees otherwise payable to financial intermediaries if the amounts due are below an amount determined by the Distributor in its sole discretion.

For Class A (with the exception noted in the next sentence), Class R and Class T shares, the Distributor begins to pay these fees immediately after purchase. For Class A shares (if purchased as part of a purchase of shares of $1 million or more for Taxable Funds or $500,000 or more for Tax-Exempt Funds) and for Class C shares (with the exception noted in the next sentence), the Distributor begins to pay these fees 12 months after purchase. For Class C shares, financial intermediaries may opt to decline the up-front payment described in Choosing a Share Class – Sales Charges and Commissions – Class C Shares – Commissions and instead may receive these fees

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immediately after purchase. If the intermediary opts to receive the up-front payment, the Distributor retains the distribution and/or service fee for the first 12 months following the sale of Class C shares in order to recover the up-front payment made to financial intermediaries and to pay for other related expenses.

Series of CFST II. The maximum fee for services under the distribution and/or shareholder servicing plan for series of CFST II is the lesser of the amount of reimbursable expenses and the fee rates in the table above. If a share class of a series of CFST II has no reimbursable distribution or shareholder servicing expenses, it will suspend the payment of any such fee.

If you maintain shares of the Fund directly with the Fund, without working with a financial advisor or other financial intermediary, distribution and service fees may be retained by the Distributor as payment or reimbursement for incurring certain distribution and shareholder service related expenses.

Over time, these distribution and/or service fees will reduce the return on your investment and may cost you more than paying other types of sales charges. The Fund will pay these fees to the Distributor and/or to eligible financial intermediaries for as long as the distribution plan and/or shareholder servicing plans continue in effect, which is expected to be indefinitely. However, the Fund may reduce or discontinue payments at any time. Your financial intermediary may also charge you other additional fees for providing services to your account, which may be different from those described here.

Class V Shareholder Services Fees

The Funds that offer Class V shares have adopted a shareholder services plan that permits them to pay for certain services provided to Class V shareholders by their financial intermediaries. Equity Funds may pay shareholder servicing fees up to an aggregate annual rate of 0.50% of the Fund's average daily net assets attributable to Class V shares (comprised of up to 0.25% for shareholder liaison services and up to 0.25% for administrative support services). Fixed income Funds may pay shareholder servicing fees up to an aggregate annual rate of 0.40% of the Fund's average daily net assets attributable to Class V shares (comprised of up to 0.20% for shareholder liaison services and up to 0.20% for administrative support services). These fees are currently limited to an aggregate annual rate of not more than 0.25% for equity Funds and not more than 0.15% for fixed income Funds. The Distributor begins to pay these fees immediately after purchase for purchases up to $1 million, for purchases of $1 million or more the Distributor will begin to pay these fees 12 months after purchase. These fees for Class V shares are not paid pursuant to a Rule 12b-1 plan. With respect to those Funds that declare dividends on a daily basis, the shareholder servicing fee shall be waived by the financial intermediaries to the extent necessary to prevent net investment income from falling below 0% on a daily basis. If you maintain shares of the Fund directly with the Fund, without working with a financial advisor or other intermediary, shareholder services fees may be retained by the Distributor as payment or reimbursement for incurring certain shareholder service related expenses.

Financial Intermediary Compensation

The Distributor, the Investment Manager and their affiliates make payments, from their own resources, to financial intermediaries, including other Ameriprise Financial affiliates, for marketing/sales support services relating to the Funds (Marketing Support Payments). Such payments are generally based upon one or more of the following factors: average net assets of the Funds attributable to that financial intermediary; gross sales of the Funds attributable to that financial intermediary; reimbursement of ticket charges (fees that a financial intermediary charges its representatives for effecting transactions in Fund shares); or a negotiated lump sum payment. While the financial arrangements may vary for each financial intermediary, Marketing Support Payments to any one financial intermediary are generally between 0.05% and 0.40% on an annual basis for payments based on average net assets of the Fund attributable to the financial intermediary, and between 0.05% and 0.25% on an annual basis for firms receiving a payment based on gross sales of the Funds attributable to the financial intermediary. The Distributor, the Investment Manager and their affiliates may at times make payments with respect to a Fund or the Columbia Funds generally on a basis other than those described above, or in larger amounts, when dealing with certain financial intermediaries. Not all financial intermediaries receive Marketing Support Payments. The Distributor, the Investment Manager and their affiliates do not make Marketing Support Payments with respect to Class Inst3 shares.

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Choosing a Share Class (continued)

In addition, the Transfer Agent has certain arrangements in place to compensate financial intermediaries, including other Ameriprise Financial affiliates, that hold Fund shares through networked and omnibus accounts, including omnibus retirement plans, for services that they provide to beneficial Fund shareholders (Shareholder Services). Shareholder Services and related fees vary by financial intermediary and according to distribution channel and may include sub-accounting, sub-transfer agency, participant recordkeeping, shareholder or participant reporting, shareholder or participant transaction processing, maintenance of shareholder records, preparation of account statements and provision of customer service, and are not intended to include services that are primarily intended to result in the sale of Fund shares. Payments for Shareholder Services generally are not expected, with certain limited exceptions, to exceed 0.40% of the average aggregate value of the Fund’s shares. Generally, each Fund pays the Transfer Agent a per account fee or a percentage of the average aggregate value of shares per annum maintained in omnibus accounts up to the lesser of the amount charged by the financial intermediary or a channel-specific or share class-specific cap established by the Board from time to time. Fee amounts in excess of the amount paid by the Fund are borne by the Transfer Agent, the Investment Manager and/or their affiliates. For Class Inst3 shares, the Transfer Agent does not pay financial intermediaries for Shareholder Services, and the Fund does not compensate the Transfer Agent for any Shareholder Services provided by financial intermediaries.

In addition to the payments described above, the Distributor, the Investment Manager and their affiliates typically make other payments or allow promotional incentives to certain broker-dealers to the extent permitted by the Securities and Exchange Commission (the SEC) and Financial Industry Regulatory Authority (FINRA) rules and by other applicable laws and regulations.

Amounts paid by the Distributor, the Investment Manager and their affiliates are paid out of their own resources and do not increase the amount paid by you or the Fund. You can find further details in the SAI about the payments made by the Distributor, the Investment Manager and their affiliates, as well as a list of the financial intermediaries, including Ameriprise Financial affiliates, to which the Distributor, the Investment Manager or their affiliates have agreed to make Marketing Support Payments and pay Shareholder Services fees.

Your financial intermediary may charge you fees and commissions in addition to those described in this prospectus. You should consult with your financial intermediary and review carefully any disclosure your financial intermediary provides regarding its services and compensation. Depending on the financial arrangement in place at any particular time, a financial intermediary and its financial advisors may have a conflict of interest or financial incentive for recommending the Fund or a particular share class over others.

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Columbia Bond Fund

Buying, Selling and Exchanging Shares (continued)

of the security. To the extent the Fund has significant holdings of small cap stocks, high-yield bonds, floating rate loans, or tax-exempt, foreign or other securities that may trade infrequently, fair valuation may be used more frequently than for other funds.

Fair valuation may have the effect of reducing stale pricing arbitrage opportunities presented by the pricing of Fund shares. However, when the Fund uses fair valuation to price securities, it may value those securities higher or lower than another fund would have priced the security. Also, the use of fair valuation may cause the Fund's performance to diverge to a greater degree from the performance of various benchmarks used to compare the Fund's performance because benchmarks generally do not use fair valuation techniques. Because of the judgment involved in fair valuation decisions, there can be no assurance that the value ascribed to a particular security is accurate. The Fund has retained one or more independent fair valuation pricing services to assist in the fair valuation process for foreign securities.

Transaction Rules and Policies

The Fund, the Distributor or the Transfer Agent may refuse any order to buy or exchange shares. If this happens, the Fund will return any money it received, but no interest will be paid on that money. Your financial intermediary may have rules and policies in place that are in addition to or different than those described below.

Order Processing

Orders to buy, sell or exchange Fund shares are processed on business days. Depending upon the class of shares, orders can be made by mail, by telephone or online. Orders received in “good form” by the Transfer Agent or your financial intermediary before the end of a business day are priced at the NAV per share of the Fund's applicable share class on that day. Orders received after the end of a business day will receive the next business day's NAV per share. When a written order to buy, sell or exchange shares is sent to the Transfer Agent, the share price used to fill the order is the next price calculated by the Fund after the Transfer Agent receives the transaction request in “good form” at its transaction processing center (i.e., the Fund’s express mail address), not the P.O. Box provided for regular mail delivery. Please note the regular and express mailing address changes for the Fund effective November 1, 2018, as described above in the Summary of the Fund – Purchase and Sale of Fund Shares section of the prospectus. The market value of the Fund's investments may change between the time you submit your order and the time the Fund next calculates its NAV per share. The business day that applies to your order is also called the trade date.

“Good Form”

An order is in “good form” if the Transfer Agent or your financial intermediary has all of the information and documentation it deems necessary to effect your order. For example, when you sell shares, “good form” means that your request (i) has complete instructions and written requests include the signatures of all account owners, (ii) is for an amount that is less than or equal to the shares in your account for which payment has been received and collected, (iii) has a Medallion Signature Guarantee for amounts greater than $100,000 and certain other transactions, as described below, and (iv) includes any other required documents completed and attached. For the documents required for sales by corporations, agents, fiduciaries, surviving joint owners and other legal entities, call 800.345.6611.

Medallion Signature Guarantees

The Transfer Agent may require a Medallion Signature Guarantee for your signature in order to process certain transactions, including if: (i) the transaction amount is over $100,000; (ii) you want your check made payable to someone other than the registered account owner(s); (iii) the address of record has changed within the last 30 days; (iv) you want the check mailed to an address other than the address of record; (v) you want proceeds to be sent according to existing bank account instructions not coded for outgoing Automated Clearing House (ACH) or wire, or to a bank account not on file; or (vi) you are changing legal ownership of your account.

A Medallion Signature Guarantee helps assure that a signature is genuine and not a forgery. A Medallion Signature Guarantee must be provided by an eligible guarantor institution including, but not limited to, the following: a bank, credit union, savings association, broker or dealer that participates in the Securities Transfer Association Medallion

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Program (STAMP), the Stock Exchange Medallion Program (SEMP) or the New York Stock Exchange Medallion Signature Program (MSP). For other transactions, the Transfer Agent may require a signature guarantee. Notarization by a notary public is not an acceptable signature guarantee. The Transfer Agent reserves the right to reject a signature guarantee and to request additional documentation for any transaction.

Customer Identification Program

Federal law requires the Fund to obtain and record specific personal information to verify your identity when you open an account. This information may include your name, address, date of birth (for individuals) and taxpayer or other government issued identification (e.g., social security number (SSN) or other taxpayer identification number (TIN)). If you fail to provide the requested information, the Fund may need to delay the date of your purchase or may be unable to open your account, which may result in a return of your investment monies. In addition, if the Fund is unable to verify your identity after your account is open, the Fund reserves the right to close your account or take other steps as deemed reasonable. The Fund will not be liable for any loss resulting from any purchase delay, application rejection or account closure due to a failure to provide proper identifying information.

Small Account Policy — Class A, Class C, Class Inst, Class T and Class V Share Accounts Below the Minimum Account Balance

The Funds generally will automatically sell your shares if the value of your Fund account (treating each account of the Fund you own separately from any other account of the Fund you may own) falls below the applicable minimum account balance. Any otherwise applicable CDSC will not be imposed on such an automatic sale of your shares. Generally, you may avoid such an automatic sale by raising your account balance to at least $250 or consolidating your multiple accounts you may have with the Funds through an exchange (so as to maintain at least $250 in each of your accounts). The minimum account balance varies among share classes and types of accounts, as follows:

    

For shares held directly with the Funds’ Transfer Agent, if your shares are sold, the Transfer Agent will remit the sale proceeds to you. The Transfer Agent will send you written notification in advance of any automatic sale, which will provide details on how you may avoid such an automatic sale. Generally, you may avoid such an automatic sale by raising your account balance to at least $250, consolidating your multiple accounts you may have with the Funds through an exchange (so as to maintain at least $250 in each of your accounts), or setting up a Systematic Investment Plan (described below). For more information, contact the Transfer Agent or your financial intermediary. The Transfer Agent's contact information (toll-free number and mailing addresses) as well as the Funds’ website address can be found at the beginning of the section Choosing a Share Class .

For shares purchased and held for your benefit through a financial intermediary, the Funds may instruct the intermediary to automatically sell your Fund shares if the transaction can be operationally administered by the intermediary.

Small Account Policy — Class A, Class C, Class Inst, Class T and Class V Share Accounts Minimum Balance Fee

If the value of your Fund account (treating each account of the Fund you own separately from any other account of the Fund you may own) falls below the minimum initial investment requirement applicable to you for any reason, including as a result of market decline, your account generally could be subject to a $20 annual fee. The Transfer Agent will reduce the expenses paid by the Fund by any amounts it collects from the assessment of this fee. For Funds that do not have transfer agency expenses against which to offset the amount collected through assessment of this fee, the

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Buying, Selling and Exchanging Shares (continued)

fee will be paid directly to the Fund. The Funds reserve the right to lower the account size trigger point for the minimum balance fee in any year or for any class of shares when we believe it is appropriate to do so in light of declines in the market value of Fund shares or for other reasons.

For shares held directly with the Funds’ Transfer Agent, this fee will be assessed through the automatic sale of Fund shares in your account. Any otherwise applicable CDSC will not be imposed on such an automatic sale of your shares. The Transfer Agent will send you written notification in advance of assessing any fee, which will provide details on how you can avoid the imposition of such fee. Generally, you may avoid the imposition of such fee by raising your Fund account balance, consolidating your multiple accounts you may have with the Funds, or setting up a Systematic Investment Plan that invests at least monthly. For more information, contact the Transfer Agent or your financial intermediary. The Transfer Agent's contact information (toll-free number and mailing addresses) as well as the Funds’ website address can be found at the beginning of the section Choosing a Share Class .

For shares purchased and held for your benefit through a financial intermediary, this fee could be assessed through the automatic sale of Fund shares in your account if instructed by the Fund and the transaction can be operationally administered by the intermediary.

Exceptions to the Small Account Policy (Accounts Below Minimum Account Balance) and Minimum Balance Fee

The automatic sale of Fund shares in accounts under $250 and the annual minimum balance fee described above do not apply to shareholders of Class Adv, Class Inst2, Class Inst3 and Class R shares; shareholders holding their shares through financial intermediary networked accounts; wrap fee and omnibus accounts; accounts with active Systematic Investment Plans; certain qualified retirement plans; and health savings accounts. The automatic sale of Fund shares of accounts under the applicable minimum account balance does not apply to individual retirement plans.

Small Account Policy — Financial Intermediary Networked and Wrap Fee Accounts

The Funds may automatically redeem, at any time, financial intermediary networked accounts and wrap fee accounts that have account balances of $20 or less or have less than one share.

For shares purchased and held for your benefit through a financial intermediary, the Funds may instruct the intermediary to automatically sell your Fund shares if the transaction can be operationally administered by the intermediary.

Information Sharing Agreements

As required by Rule 22c-2 under the 1940 Act, the Funds or certain of their service providers will enter into information sharing agreements with financial intermediaries, including participating life insurance companies and financial intermediaries that sponsor or offer retirement plans through which shares of the Funds are made available for purchase. Pursuant to Rule 22c-2, financial intermediaries are required, upon request, to: (i) provide shareholder account and transaction information; and (ii) execute instructions from the Fund to restrict or prohibit further purchases of Fund shares by shareholders who have been identified by the Fund as having engaged in transactions that violate the Fund's excessive trading policies and procedures.

Excessive Trading Practices Policy of Non-Money Market Funds

Right to Reject or Restrict Share Transaction Orders— The Fund is intended for investors with long-term investment purposes and is not intended as a vehicle for frequent trading activity (market timing) that is excessive. Investors should transact in Fund shares primarily for investment purposes. The Board has adopted excessive trading policies and procedures that are designed to deter excessive trading by investors (the Excessive Trading Policies and Procedures). The Fund discourages and does not accommodate excessive trading.

The Fund reserves the right to reject, without any prior notice, any purchase or exchange order for any reason, and will not be liable for any loss resulting from rejected orders. For example, the Fund may in its sole discretion restrict or reject a purchase or exchange order even if the transaction is not subject to the specific limitation described below if the Fund or its agents determine that accepting the order could interfere with efficient management of the Fund's

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Buying, Selling and Exchanging Shares (continued)

portfolio or is otherwise contrary to the Fund's best interests. The Excessive Trading Policies and Procedures apply equally to purchase or exchange transactions communicated directly to the Transfer Agent and to those received by financial intermediaries.

Specific Buying and Exchanging Limitations — If a Fund detects that an investor has made two “material round trips” in any 28-day period, it will generally reject the investor's future purchase orders, including exchange purchase orders, involving any Fund.

For these purposes, a “round trip” is a purchase or exchange into the Fund followed by a sale or exchange out of the Fund, or a sale or exchange out of the Fund followed by a purchase or exchange into the Fund. A “material” round trip is one that is deemed by the Fund to be material in terms of its amount or its potential detrimental impact on the Fund. Independent of this limit, the Fund may, in its sole discretion, reject future purchase orders by any person, group or account that appears to have engaged in any type of excessive trading activity.

These limits generally do not apply to automated transactions or transactions by registered investment companies in a “fund-of-funds” structure. These limits do not apply to payroll deduction contributions by retirement plan participants, transactions initiated by a retirement plan sponsor or certain other retirement plan transactions consisting of rollover transactions, loan repayments and disbursements, and required minimum distribution redemptions. They may be modified or rescinded for accounts held by certain retirement plans to conform to plan limits, for considerations relating to the Employee Retirement Income Security Act of 1974 or regulations of the Department of Labor, and for certain asset allocation or wrap programs. Accounts known to be under common ownership or control generally will be counted together, but accounts maintained or managed by a common intermediary generally will not be considered to be under common ownership or control. The Fund retains the right to modify these restrictions at any time without prior notice to shareholders. In addition, the Fund may, in its sole discretion, reinstate trading privileges that have been revoked under the Fund's Excessive Trading Policies and Procedures.

Limitations on the Ability to Detect and Prevent Excessive Trading Practices— The Fund takes various steps designed to detect and prevent excessive trading, including daily review of available shareholder transaction information. However, the Fund receives buy, sell or exchange orders through financial intermediaries, and cannot always know of or reasonably detect excessive trading that may be facilitated by financial intermediaries or by the use of the omnibus account arrangements they offer. Omnibus account arrangements are common forms of holding shares of mutual funds, particularly among certain financial intermediaries such as broker-dealers, retirement plans and variable insurance products. These arrangements often permit financial intermediaries to aggregate their clients' transactions and accounts, and in these circumstances, the identities of the financial intermediary clients that beneficially own Fund shares are often not known to the Fund.

Some financial intermediaries apply their own restrictions or policies to their clients’ transactions and accounts, which may be more or less restrictive than those described here. This may impact the Fund's ability to curtail excessive trading, even where it is identified. For these and other reasons, it is possible that excessive trading may occur despite the Fund's efforts to detect and prevent it.

Although these restrictions and policies involve judgments that are inherently subjective and may involve some selectivity in their application, the Fund seeks to act in a manner that it believes is consistent with the best interests of Fund shareholders in making any such judgments.

Risks of Excessive Trading — Excessive trading creates certain risks to the Fund's long-term shareholders and may create the following adverse effects:

■	negative impact on the Fund's performance;

■	potential dilution of the value of the Fund's shares;

■	interference with the efficient management of the Fund's portfolio, such as the need to maintain undesirably large cash positions, the need to use its line of credit or the need to buy or sell securities it otherwise would not have bought or sold;

■	losses on the sale of investments resulting from the need to sell securities at less favorable prices;

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■	increased taxable gains to the Fund's remaining shareholders resulting from the need to sell securities to meet sell orders; and

■	increased brokerage and administrative costs.

To the extent that the Fund invests significantly in foreign securities traded on markets that close before the Fund's valuation time, it may be particularly susceptible to dilution as a result of excessive trading. Because events may occur after the close of foreign markets and before the Fund's valuation time that influence the value of foreign securities, investors may seek to trade Fund shares in an effort to benefit from their understanding of the value of foreign securities as of the Fund's valuation time. This is often referred to as price arbitrage. The Fund has adopted procedures designed to adjust closing market prices of foreign securities under certain circumstances to reflect what the Fund believes to be the fair value of those securities as of its valuation time. To the extent the adjustments do not work fully, investors engaging in price arbitrage may cause dilution in the value of the Fund's shares held by other shareholders.

Similarly, to the extent that the Fund invests significantly in thinly traded securities and other debt instruments that are rated below investment grade (commonly called “high-yield” or “junk” bonds), equity securities of small-capitalization companies, floating rate loans, or tax-exempt or other securities that may trade infrequently, because

these securities are often traded infrequently, investors may seek to trade Fund shares in an effort to benefit from their understanding of the value of these securities as of the Fund's valuation time. This is also a type of price arbitrage. Any such frequent trading strategies may interfere with efficient management of the Fund's portfolio to a greater degree than would be the case for mutual funds that invest only, or significantly, in highly liquid securities, in part because the Fund may have difficulty selling these particular investments at advantageous times or prices to satisfy large and/or frequent sell orders. Any successful price arbitrage may also cause dilution in the value of Fund shares held by non-redeeming shareholders.

Excessive Trading Practices Policy of Columbia Government Money Market Fund

A money market fund is designed to offer investors a liquid cash option that they may buy and sell as often as they wish. Accordingly, the Board has not adopted policies and procedures designed to discourage excessive or short-term trading of Columbia Government Money Market Fund shares. However, since frequent purchases and sales of Columbia Government Money Market Fund shares could in certain instances harm shareholders in various ways, including reducing the returns to long-term shareholders by increasing costs (such as spreads paid to dealers who trade money market instruments with Columbia Government Money Market Fund) and disrupting portfolio management strategies, Columbia Government Money Market Fund reserves the right, but has no obligation, to reject any purchase or exchange transaction at any time. Except as expressly described in this prospectus (such as minimum purchase amounts), Columbia Government Money Market Fund has no limits on purchase or exchange transactions. In addition, Columbia Government Money Market Fund reserves the right to impose or modify restrictions on purchases, exchanges or trading of Fund shares at any time.

Opening an Account and Placing Orders

We encourage you to consult with a financial advisor who can help you with your investment decisions and who can help you open an account. Once you have an account, you can buy, sell or exchange shares by contacting your financial advisor who will send your order to the Transfer Agent or your financial intermediary. As described below, once you have an account you can also communicate your orders directly to the Transfer Agent by mail, by telephone or online (except that purchases of Class T shares must be made through a Class T Intermediary).

The Funds are generally available directly (except for Class T shares) and through broker-dealers, banks and other financial intermediaries or institutions, and through certain qualified and non-qualified plans, wrap fee products or other investment products sponsored by financial intermediaries. You may sell or exchange shares through your financial intermediary. If you maintain your account directly with your financial intermediary, you must contact that agent to process your transaction.

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Not all financial intermediaries offer the Funds (or all classes of Fund shares) and certain financial intermediaries that offer the Funds may not offer all Funds on all investment platforms or programs. Please consult with your financial intermediary to determine the availability of the Funds. If you set up an account at a financial intermediary that does not have, and is unable to obtain, a selling agreement with the Distributor, you will not be able to transfer Fund holdings to that account. In that event, you must either maintain your Fund holdings with your current financial intermediary or find another financial intermediary with a selling agreement.

Financial intermediaries that offer the Funds may charge you additional fees for the services they provide and they may have different policies that are not described in this prospectus. An investor transacting in a class of Fund shares without any front-end sales charge, CDSC, or other asset-based fee for sales or distribution, such as a Rule 12b-1 fee, may be required to pay a commission to the financial intermediary for effecting such transactions. The Funds are offered in a number of different share classes that have different fees and expenses and other features. Some differences in the policies of different financial intermediaries may include different minimum investment amounts, exchange privileges, Fund/class choices and cutoff times for investments. Additionally, recordkeeping, transaction processing and payments of distributions relating to your account may be performed by the financial intermediaries through which your shares of the Fund are held. Since the Fund (and its service providers) may not have a record of your account transactions, you should always contact the financial intermediary through which you purchased or at which you maintain your shares of the Fund to make changes to your account, to give instructions concerning your account, or to obtain information about your account. The Fund and its service providers, including the Distributor and the Transfer Agent, are not responsible for the failure of any financial intermediary to carry out its obligations to its customers.

The Fund may engage financial intermediaries to receive purchase, exchange and sell orders on its behalf. Accounts established directly with the Fund will be serviced by the Transfer Agent. The Funds, the Transfer Agent and the Distributor do not provide investment advice.

Direct-At-Fund Accounts (Accounts Established Directly with the Fund)

You can hold Fund shares through an account established and held through the financial intermediary through which you purchased Fund shares or, with the exception of Class T shares, you or your financial intermediary may establish an account directly with the Fund, in which case you will receive Fund account transaction confirmations and statements from the Transfer Agent, and not your financial intermediary (Direct-at-Fund Accounts).

To open a Direct-at-Fund Account, complete a Fund account application with your financial advisor or investment professional, and mail the account application to the Transfer Agent. Account applications may be obtained at columbiathreadneedleus.com or may be requested by calling 800.345.6611. Make your check payable to the Fund. You will be assessed a $15 fee for any checks rejected by your financial institution due to insufficient funds or other reasons. The Funds do not accept cash, credit card convenience checks, money orders, traveler's checks, starter checks, third or fourth party checks, or other cash equivalents.

Mail your check and completed application to the Transfer Agent at its regular or express mail address that can be found at the beginning of the section Choosing a Share Class . You may also use these addresses to request an exchange or redemption of Fund shares. When a written order to buy, sell or exchange shares is sent to the Transfer Agent, the share price used to fill the order is the next price calculated by the Fund after the Transfer Agent receives your transaction request in “good form” at its transaction processing center (i.e., the Fund’s express mail address), not the P.O. Box provided for regular mail delivery. Please note the regular and express mailing address changes for the Fund effective November 1, 2018, as described above in the Summary of the Fund – Purchase and Sale of Fund Shares section of the prospectus.

You will be sent a statement confirming your purchase and any subsequent transactions in your account. You will also be sent quarterly and annual statements detailing your transactions in the Fund and the other Funds you own under the same account. Duplicate quarterly account statements for the current year and duplicate annual statements for the most recent prior calendar year will be sent to you free of charge. Copies of year-end statements for prior years are available for a fee. Please contact the Transfer Agent for more information.

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Written Transactions – Direct-at-Fund Accounts

If you have a Direct-at-Fund Account, you can communicate written buy, sell or exchange orders to the Transfer Agent at its address that can be found at the beginning of the section Choosing a Share Class . When a written order to buy, sell or exchange shares is sent to the Transfer Agent, the share price used to fill the order is the next price calculated by the Fund after the Transfer Agent receives your transaction request in “good form” at its transaction processing center (i.e., the Fund’s express mail address), not the P.O. Box provided for regular mail delivery. Please note the regular and express mailing address changes for the Fund effective November 1, 2018, as described above in the Summary of the Fund – Purchase and Sale of Fund Shares section of the prospectus.

Include in your transaction request letter: your name; the name of the Fund(s); your account number; the class of shares to be purchased, exchanged or sold; your SSN or other TIN; the dollar amount or number of shares you want to purchase, exchange or sell; specific instructions regarding delivery of any redemption proceeds or exchange destination (i.e., the Fund/class to be exchanged into); signature(s) of all registered account owner(s); and any special documents the Transfer Agent may require in order to process your order.

Corporate, trust or partnership accounts may need to send additional documents. Payment will be mailed to the address of record and made payable to the names listed on the account, unless your request specifies differently and is signed by all owners.

Telephone Transactions – Direct-at-Fund Accounts

For Class A, Class C, Class Inst, Class Inst3, Class R and Class V shares, if you have a Direct-at-Fund Account, you may place orders to buy, sell or exchange shares by telephone through the Transfer Agent. To place orders by telephone, call 800.422.3737. Have your account number and SSN or TIN available when calling.

You can sell Fund shares via the telephone and receive redemption proceeds: by electronic funds transfer via ACH or by check to the address of record, subject to a maximum of $100,000 of shares per day, per Fund account; or by wire, subject to a maximum of $3 million of shares per day, per Fund account. You can buy Fund shares via the telephone by electronic funds transfer via ACH from your bank account up to a maximum of $100,000 of shares per day, per Fund account. Certain restrictions apply, so please call the Transfer Agent at 800.422.3737 for this and other information in advance of any need to transact via telephone.

Telephone orders may not be as secure as written orders. The Fund will take reasonable steps to confirm that telephone instructions are genuine. For example, we require proof of your identification before we will act on instructions received by telephone and may record telephone conversations. However, the Fund and its agents will not be responsible for any losses, costs or expenses resulting from an unauthorized telephone instruction when reasonable steps have been taken to confirm that telephone instructions are genuine. Telephone orders may be difficult to complete during periods of significant economic or market change or business interruption.

Online Transactions – Direct-at-Fund Accounts

For Class A, Class C, Class Inst, Class Inst3, Class R and Class V shares, if you have a Direct-at-Fund Account, you may be able to place orders to buy, sell, or exchange shares online. Contact the Transfer Agent at 800.345.6611 for more information on certain account trading restrictions and the special sign-up procedures required for online transactions. You can also go to www.columbiathreadneedleus.com/investor/ to sign up for online transactions. The Transfer Agent has procedures in place to authenticate electronic orders you send through the internet. You will be required to accept the terms of an online agreement and to establish an online account and utilize a password in order to access online account services. You can sell a maximum of $100,000 of shares per day, per Fund account through your online account if you qualify for internet orders. Wire transactions are not permitted online.

Wire Transactions – Direct-at-Fund Accounts

If you hold a Direct-at-Fund Account, you may purchase or redeem Class A, Class C, Class Inst, Class Inst3 and Class V shares of a Fund by wiring money from (or to) your bank account to (or from) your Fund account. You must set up this feature prior to your request unless you are submitting your request in writing with a Medallion Signature Guarantee. Please contact the Transfer Agent by calling 800.422.3737 to obtain the necessary forms and requirements. The Transfer Agent charges a fee for shares sold by Fedwire. The Transfer Agent may waive the fee for

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certain accounts. In the case of a redemption, the receiving bank may charge an additional fee. The minimum amount that can be redeemed by wire is $500. When selling Fund shares via a telephone request, the maximum amount that can be redeemed via wire transfer is $3 million per day, per Fund account.

Electronic Funds Transfer via ACH – Direct-at-Fund Accounts

If you hold a Direct-at-Fund Account, you may purchase or redeem Class A, Class C, Class Inst, Class Inst3 and Class V shares of a Fund by electronically transferring money via Automated Clearing House (ACH) from (or to) your bank account to (or from) your Fund account subject to a maximum of $100,000 of shares per day, per Fund account. You must set up this feature prior to your request, unless you are submitting your request in writing with a Medallion Signature Guarantee. Please contact the Transfer Agent by calling 800.422.3737 to obtain the necessary forms and requirements. Your bank may take up to three business days to post an electronic funds transfer to (or from) your Fund account.

Buying Shares

Eligible Investors

Class A Shares

Class A shares are available to the general public for investment.

Class Adv Shares

Class Adv shares are available only to (i) omnibus retirement plans, including self-directed brokerage accounts within omnibus retirement plans that clear through institutional no transaction fee (NTF) platforms, (ii) trust companies or similar institutions, (iii) broker-dealers, banks, trust companies and similar institutions that clear Fund share transactions for their client or customer investment advisory or similar accounts through designated financial intermediaries and their mutual fund trading platforms that have been granted specific written authorization from the Transfer Agent with respect to Class Adv eligibility apart from selling, servicing or similar agreements, (iv) 501(c)(3) charitable organizations, (v) 529 plans, (vi) health savings accounts, (vii) investors participating in a fee-based advisory program sponsored by a financial intermediary or other entity that is not compensated by the Fund for those services, other than payments for shareholder servicing or sub-accounting performed in place of the Transfer Agent, and (viii) commissionable brokerage platforms where the financial intermediary, acting as broker on behalf of its customer, charges the customer a commission for effecting transactions in Fund shares, provided that the financial intermediary has an agreement with the Distributor that specifically authorizes offering Class Adv shares within such platform.

Class C Shares

Class C shares are available to the general public for investment.

Class Inst Shares

Class Inst shares are available only to the categories of eligible investors described below under Class Inst Shares Minimum Initial Investments . Financial intermediaries that clear Fund share transactions through designated financial intermediaries and their mutual fund trading platforms that were given specific written notice from the Transfer Agent of the termination, effective March 29, 2013, of their eligibility for new purchases of Class Inst shares and omnibus retirement plans are not permitted to establish new Class Inst accounts, subject to certain exceptions described below.

Omnibus retirement plans that opened and, subject to certain exceptions, funded a Class Inst account with the Fund as of the close of business on March 28, 2013 and have continuously held Class Inst shares in such account after such date (each, a grandfathered plan), may generally continue to make additional purchases of Class Inst shares, open new Class Inst accounts and add new participants. In addition, an omnibus retirement plan affiliated with a grandfathered plan may, in the sole discretion of the Distributor, open new Class Inst accounts in a Fund if the affiliated plan opened a Class Inst account on or before March 28, 2013. If an omnibus retirement plan invested in

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Class Inst shares changes recordkeepers after March 28, 2013, any new accounts established for that plan may not be established in Class Inst shares, but such a plan may establish new accounts in a different share class for which the plan is eligible.

Accounts of financial intermediaries (other than omnibus retirement plans, which are discussed above) that clear Fund share transactions for their client or customer accounts through designated financial intermediaries and their mutual fund trading platforms that received specific written notice from the Transfer Agent of the termination, effective March 29, 2013, of their eligibility for new purchases of Class Inst shares will not be permitted to establish new Class Inst accounts or make additional purchases of Class Inst shares (other than through reinvestment of distributions). Any such account may, at its holder’s option, exchange Class Inst shares of a Fund, without the payment of a sales charge, for Class A shares of the same Fund.

Class Inst2 Shares

Class Inst2 shares are available only to (i) certain registered investment advisers and family offices that clear Fund share transactions for their client or customer accounts through designated financial intermediaries and their mutual fund trading platforms that have been granted specific written authorization from the Transfer Agent with respect to Class Inst2 eligibility apart from selling, servicing or similar agreements; (ii) omnibus retirement plans; and (iii) institutional investors that are clients of the Columbia Threadneedle Global Institutional Distribution Team that invest in Class Inst2 shares for their own account through platforms approved by the Distributor or an affiliate thereof to offer and/or service Class Inst2 shares within such platform. Prior to November 8, 2012, Class Inst2 shares were closed to new investors and new accounts, subject to certain exceptions. Existing shareholders who do not satisfy the new eligibility requirements for investment in Class Inst2 may not establish new Class Inst2 accounts but may continue to make additional purchases of Class Inst2 shares in accounts opened and funded prior to November 8, 2012; provided, however, that investment advisory programs and similar programs that opened a Class Inst2 account as of May 1, 2010, and continuously hold Class Inst2 shares in such account after such date, may generally not only continue to make additional purchases of Class Inst2 shares but also open new Class Inst2 accounts for such pre-existing programs and add new shareholders in the program.

Class Inst3 Shares

Class Inst3 shares are available to: (i) group retirement plans that maintain plan-level or omnibus accounts with the Fund (through the Transfer Agent); (ii) institutional investors that are clients of the Columbia Threadneedle Global Institutional Distribution Team that invest in Class Inst3 shares for their own account through platforms approved by the Distributor or an affiliate thereof to offer and/or service Class Inst3 shares within such platform; (iii) collective trust funds; (iv) affiliated or unaffiliated mutual funds (e.g., funds operating as funds-of-funds); (v) fee-based platforms of financial intermediaries (or the clearing intermediary that they trade through) that have an agreement with the Distributor or an affiliate thereof that specifically authorizes the financial intermediary to offer and/or service Class Inst3 shares within such platform, provided also that Fund shares are held in an omnibus account; (vi) commissionable brokerage platforms where the financial intermediary, acting as broker on behalf of its customer, charges the customer a commission for effecting transactions in Fund shares, provided that the financial intermediary has an agreement with the Distributor that specifically authorizes offering Class Inst3 shares within such platform and that Fund shares are held in an omnibus account; and (vii) bank trust departments, subject to an agreement with the Distributor that specifically authorizes offering Class Inst3 shares and provided that Fund shares are held in an omnibus account. In each case above where noted that Fund shares are required to be held in an omnibus account, the Distributor may, in its discretion, determine to waive this requirement.

Class R Shares

Class R shares are available only to eligible health savings accounts sponsored by third party platforms, including those sponsored by Ameriprise Financial affiliates, eligible retirement plans and, in the sole discretion of the Distributor, other types of retirement accounts held through platforms maintained by financial intermediaries approved by the Distributor. Eligible retirement plans include any retirement plan other than individual 403(b) plans.

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Class R shares are generally not available for investment through retail nonretirement accounts, traditional and Roth IRAs, Coverdell Education Savings Accounts, SEPs, SAR-SEPs, Simple IRAs or 529 tuition programs. Contact the Transfer Agent or your retirement plan or health savings account administrator for more information about investing in Class R shares.

Class T Shares

Class T shares are available to the general public. Class T shares must be purchased through a Class T Intermediary (as defined above).

Class V Shares

Class V shares are available only to investors who received (and who have continuously held) Class V shares (formerly named Class T shares, which have no relation to a Fund’s current Class T shares) in connection with the merger of certain Galaxy funds into certain Funds that were then named Liberty funds.

Additional Eligible Investors

In addition, the Distributor, in its sole discretion, may accept investments in any share class from investors other than those listed in this prospectus, and may also waive certain eligibility requirements for operational and other reasons, including but not limited to any requirement to maintain Fund shares in networked or omnibus accounts.

Minimum Initial Investments

The table below shows the Fund’s minimum initial investment requirements, which may vary by class and type of account.

The Fund reserves the right to redeem your shares if your account falls below the Fund’s minimum initial investment requirement.

    

(a)

If your Class A, Class Adv, Class C, Class Inst, Class Inst3 or Class V shares account balance falls below the minimum initial investment amount for any reason, including a market decline, you may be asked to increase it to the minimum initial investment amount or establish a monthly Systematic Investment Plan. If you do not do so, your account will be subject to a $20 annual low balance fee and/or shares may be automatically redeemed and the proceeds mailed to you if the account falls below the minimum account balance. See Buying, Selling and Exchanging Shares — Transaction Rules and Policies above. There is no minimum initial investment in Class A shares for accounts held in an omnibus account on a mutual fund only platform offered through your financial intermediary.

(b)	Columbia Government Money Market Fund — $2,000

(c)	Columbia Government Money Market Fund — $1,000

(d)

The minimum initial investment in Class Adv shares is $2,000 ($1,000 for IRAs; $100 for systematic investment plan accounts) for commissionable brokerage platforms where the financial intermediary, acting as broker on behalf of its customers, charges the customer a commission for effecting transactions in Fund shares, provided that the financial intermediary has an agreement with the Distributor that specifically authorizes offering Class Adv shares within such platform; for all other eligible Class Adv share investors (see Buying Shares – Eligible Investors – Class Adv Shares above), there is no minimum initial investment. The minimum initial investment amount for Class Inst shares is $0, $1,000 or $2,000 depending upon the category of eligible investor. See — Class Inst Shares Minimum Initial Investments below. The minimum initial investment amount for systematic investment plan accounts is the same as the amount set forth in the first two rows of the table, as applicable.

(e)	There is no minimum initial investment in Class Inst3 shares for: group retirement plans that maintain plan-level or omnibus accounts with the Fund; collective trust funds; affiliated or unaffiliated mutual funds (e.g., funds operating as funds-of-funds); and fee-based platforms of financial

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intermediaries (or the clearing intermediary that they trade through) that have an agreement with the Distributor or an affiliate thereof that specifically authorizes the financial intermediary to offer and/or service Class Inst3 shares within such platform and Fund shares are held in an omnibus account. The minimum initial investment in Class Inst3 shares is $2,000 ($1,000 for IRAs; $100 for systematic investment plan accounts) for commissionable brokerage platforms where the financial intermediary, acting as broker on behalf of its customer, charges the customer a commission for effecting transactions in Fund shares, provided that the financial intermediary has an agreement with the Distributor that specifically authorizes offering Class Inst3 shares within such platform and Fund shares are held in an omnibus account. The minimum initial investment in Class Inst3 shares is $1 million, unless waived in the discretion of the Distributor, for the following investors: institutional investors that are clients of the Columbia Threadneedle Global Institutional Distribution Team that invest in Class Inst3 shares for their own account through platforms approved by the Distributor or an affiliate thereof to offer and/or service Class Inst3 shares within such platform; and bank trust departments, subject to an agreement with the Distributor that specifically authorizes offering Class Inst3 shares and provided that Fund shares are held in an omnibus account. The Distributor may, in its discretion, waive the $1 million minimum initial investment required for these Class Inst3 investors. In each case above where noted that Fund shares are required to be held in an omnibus account, the Distributor may, in its discretion, determine to waive this requirement.

Additional Information about Minimum Initial Investments

The minimum initial investment requirements may be waived for accounts that are managed by an investment professional, or for accounts held in approved discretionary or non-discretionary wrap programs. The Distributor, in its sole discretion, may also waive minimum initial investment requirements for other account types.

Minimum investment and related requirements may be modified at any time, with or without prior notice. If your account is closed and then re-opened with a systematic investment plan, your account must meet the then-current applicable minimum initial investment.

Class Inst Shares Minimum Initial Investments

There is no minimum initial investment in Class Inst shares for the following categories of eligible investors:

■	Any health savings account sponsored by a third party platform.

■

Any investor participating in an account sponsored by a financial intermediary or other entity (that provides services to the account) that is paid a fee-based advisory fee by the investor and that is not compensated by the Fund for those services, other than payments for shareholder servicing or sub-accounting performed in place of the Transfer Agent.

The minimum initial investment in Class Inst shares for the following categories of eligible investors is $1,000:

■

Individual retirement accounts (IRAs) on commissionable brokerage platforms where the financial intermediary, acting as broker on behalf of its customer, charges the customer a commission for effecting transactions in Fund shares, provided that the financial intermediary has an agreement with the Distributor that specifically authorizes offering Class Inst shares within such platform.

■

Any current employee of Columbia Management Investment Advisers LLC, the Distributor or the Transfer Agent and immediate family members of any of the foregoing who share the same address are eligible to invest in Class Inst shares through an individual retirement account (IRA). If you maintain your account with a financial intermediary, you must contact that financial intermediary each time you seek to purchase shares to notify them that you qualify for Class Inst shares. If Class Inst shares are not available at your financial intermediary, you may consider opening a Direct-at-Fund Account. It is your obligation to advise your financial intermediary or (in the case of Direct-at-Fund Accounts) the Transfer Agent that you qualify for Class Inst shares; be prepared to provide proof thereof.

The minimum initial investment in Class Inst shares for the following categories of eligible investors is $2,000:

■

Investors (except investors in individual retirement accounts (IRAs)) who purchase Fund shares through commissionable brokerage platforms where the financial intermediary holds the shares in an omnibus account and, acting as broker on behalf of its customer, charges the customer a commission for effecting transactions in Fund shares provided that the financial intermediary has an agreement with the Distributor that specifically authorizes offering Class Inst shares within such platform.

■

Any current employee of Columbia Management Investment Advisers LLC, the Distributor or the Transfer Agent and immediate family members of any of the foregoing who share the same address are eligible to invest in Class Inst shares (other than individual retirement accounts (IRAs), for which the minimum initial investment is $1,000). If you maintain your account with a financial intermediary, you must contact that financial intermediary each time you seek to purchase shares to notify them that you qualify for Class Inst shares. If Class Inst shares are not available

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at your financial intermediary, you may consider opening a Direct-at-Fund Account. It is your obligation to advise your financial intermediary or (in the case of Direct-at-Fund Accounts) the Transfer Agent that you qualify for Class Inst shares; be prepared to provide proof thereof.

■	Certain financial institutions and intermediaries, such as insurance companies, trust companies, banks, endowments, investment companies or foundations, buying shares for their own account, including Ameriprise Financial and its affiliates and/or subsidiaries.

■	Bank trust departments that assess their clients an asset-based fee.

■	Certain other investors as set forth in more detail in the SAI.

Systematic Investment Plan

The Systematic Investment Plan allows you to schedule regular purchases via automatic transfers from your bank account to the Fund on a monthly, quarterly or semiannual basis. Contact the Transfer Agent or your financial intermediary to set up the plan. Systematic Investment Plans may not be available for all share classes. With the exception of Columbia Government Money Market Fund, the Systematic Investment Plan is confirmed on your quarterly account statement.

Dividend Diversification

Generally, you may automatically invest Fund distributions into the same class of shares (and in some cases certain other classes of shares, but not Class T shares) of another Fund without paying any applicable front-end sales charge. Call the Transfer Agent at 800.345.6611 for details. The ability to invest distributions from one Fund to another Fund may not be available to accounts held at all financial intermediaries.

Other Purchase Rules You Should Know

■	Once the Transfer Agent or your financial intermediary receives your purchase order in “good form,” your purchase will be made at the Fund’s next calculated public offering price per share, which is the NAV per share plus any sales charge that applies (i.e., the trade date).

■	Once the Fund receives your purchase request in “good form,” you cannot cancel it after the market closes.

■	You generally buy Class A, Class T and Class V shares at the public offering price per share because purchases of these share classes are generally subject to a front-end sales charge.

■	You buy Class Adv, Class C, Class Inst, Class Inst2, Class Inst3 and Class R shares at NAV per share because no front-end sales charge applies to purchases of these share classes.

■	The Distributor and the Transfer Agent reserve the right to cancel your order if the Fund does not receive payment within two business days of receiving your purchase order. The Fund will return any payment received for orders that have been cancelled, but no interest will be paid on that money.

■	Financial intermediaries are responsible for sending your purchase orders to the Transfer Agent and ensuring that the Fund receives your money on time.

■	Shares purchased are recorded on the books of the Fund. The Fund does not issue certificates.

Please also read Appendix A and contact your financial intermediary for more information regarding any reductions and/or waivers described therein.

Selling Shares

When you sell shares, the amount you receive may be more or less than the amount you invested. Your sale price will be the next NAV calculated after your request is received in “good form,” (i.e., the trade date) minus any applicable CDSC.

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Buying, Selling and Exchanging Shares (continued)

Systematic Withdrawal Plan

The Systematic Withdrawal Plan allows you to schedule regular redemptions from your account any business day on a monthly, quarterly or semiannual basis. Currently, Systematic Withdrawal Plans are generally available for Class A, Class Adv, Class C, Class Inst, Class Inst2, Class Inst3, Class T and Class V share accounts. Contact the Transfer Agent or your financial intermediary to set up the plan. To set up the plan, your account balance must meet the class minimum initial investment amount. A Systematic Withdrawal Plan cannot be set up on an account that already has a Systematic Investment Plan established. Note that a Medallion Signature Guarantee may be required if this service is established after your Fund account is opened.

You can choose to receive your withdrawals via check or direct deposit into your bank account. The Fund will deduct any applicable CDSC from the withdrawals before sending redemption proceeds to you. You can cancel the plan by giving the Fund 30 days’ notice in writing or by calling the Transfer Agent at 800.422.3737. It’s important to remember that if you withdraw more than your investment in the Fund is earning, you'll eventually withdraw your entire investment.

Check Redemption Service (for Columbia Government Money Market Fund)

Class A and Class Inst shares of Columbia Government Money Market Fund (which is not offered in this prospectus) offer check writing privileges. If you have $2,000 in Columbia Government Money Market Fund, you may request checks which may be drawn against your account. The amount of any check drawn against your Columbia Government Money Market Fund must be at least $100 and not more than $100,000 per day. You can elect this service when you initially establish your account or thereafter. Call 800.345.6611 for the appropriate forms to establish this service. If you own Class A shares that were originally purchased in another Fund at NAV because of the size of the purchase, and then exchanged into Columbia Government Money Market Fund, check redemptions may be subject to a CDSC. A $15 charge will be assessed for any stop payment order requested by you or any overdraft in connection with checks written against your Columbia Government Money Market Fund account. Note that a Medallion Signature Guarantee may be required if this service is established after your Fund account is opened.

Satisfying Fund Redemption Requests

When you sell your Fund shares, the Fund is effectively buying them back from you. This is called a redemption. Except as noted below with respect to newly purchased shares, the Fund typically expects to send you payment for your shares within two business days after your trade date. The Fund can suspend redemptions and/or delay payment of redemption proceeds for up to seven days. The Fund can also suspend redemptions and/or delay payment of redemption proceeds in excess of seven days under certain circumstances, including when the NYSE is closed or trading thereon is restricted or during emergency or other circumstances, including as determined by the SEC.

The Fund typically seeks to satisfy redemption requests from cash or cash equivalents held by the Fund, from the proceeds of orders to purchase Fund shares or from the proceeds of sales of Fund holdings effected in the normal course of managing the Fund. However, the Fund may have to sell Fund holdings, including in down markets, to meet heavier than usual redemption requests. For example, under stressed or abnormal market conditions or circumstances, including circumstances adversely affecting the liquidity of the Fund’s investments, the Fund may be more likely to be forced to sell Fund holdings to meet redemptions than under normal market circumstances. In these situations, the Fund’s portfolio managers may have to sell Fund holdings that would not otherwise be sold because, among other reasons, the current price to be received is less than the value of the holdings perceived by the Fund’s portfolio managers. The Fund may also, under certain circumstances (but more likely under stressed or abnormal market conditions or circumstances), borrow money under a credit facility to which the Fund and certain other Columbia Funds are parties or from other Columbia Funds under an interfund lending program (except for closed-end funds and money market funds, which are not eligible to borrow under the program). The Fund and the other Columbia Funds are limited as to the amount that each may individually and collectively borrow under the credit facility and the interfund lending program. As a result, borrowings available to the Fund under the credit facility and the interfund lending program might be insufficient, alone or in combination with the other strategies described herein, to satisfy Fund redemption requests. Please see About Fund Investments – Borrowings – Interfund Lending in the SAI for more information about the credit facility and interfund lending program. The Fund is also limited in the

64	Prospectus 2018

Columbia Bond Fund

Buying, Selling and Exchanging Shares (continued)

total amount it may borrow. The Fund may only borrow to the extent permitted by the 1940 Act, the rules and regulations thereunder, and any exemptive relief available to the Fund, which currently limit Fund borrowings to 33 1/3% of total assets (including any amounts borrowed) less liabilities (other than borrowings), plus an additional 5% of its total assets for temporary purposes (to be repaid within 60 days without extension or renewal), in each case determined at the time the borrowing is made.

In addition, the Fund reserves the right to honor redemption orders in whole or in part with in-kind distributions of Fund portfolio securities instead of cash. Such in-kind distributions typically represent a pro-rata portion of Fund portfolio assets subject to adjustments (e.g., for non-transferable securities, round lots, and derivatives). In the event the Fund distributes portfolio securities in kind, you may incur brokerage and other transaction costs associated with converting the portfolio securities you receive into cash. Also, the portfolio securities you receive may increase or decrease in value after they are distributed but before you convert them into cash. For U.S. federal income tax purposes, redemptions paid in securities are generally treated the same as redemptions paid in cash. If, during any 90-day period, you redeem shares in an amount greater than $250,000 or 1% of the Fund’s net assets (whichever is less), and if the Investment Manager determines it to be feasible and appropriate, the Fund may pay the redemption amount above such threshold by an in-kind distribution of Fund portfolio securities.

While the Fund is not required (and may refuse in its discretion) to pay a redemption with an in-kind distribution of Fund portfolio securities and reserves the right to pay the redemption proceeds in cash, if you wish to request an in-kind redemption, please call the Transfer Agent at 800.345.6611. As a result of the operational steps needed to coordinate with the redeeming shareholder’s custodian, in-kind redemptions typically take several weeks to complete after a redemption request is received. The Fund and the redeeming shareholder will typically agree upon a redemption date. Since the Fund’s NAV may fluctuate during this time, the Fund’s NAV may be lower on the agreed-upon redemption date than on an earlier date on which the investment could have been redeemed for cash.

Redemption of Newly Purchased Shares

You may not redeem shares for which the Fund has not yet received payment. If you pay for shares by check or electronically by ACH and your purchase payment is not guaranteed, it may take up to 10 calendar days to clear. Only shares that have been held in your account for 10 calendar days after the trade date of the purchase will be considered to be in “good form” for redemption (Collected Shares). If you request a redemption for an amount that, based on the NAV next calculated after your redemption request is received, includes any shares that are not yet Collected Shares, the Fund will only process the redemption up to the amount of the value of Collected Shares available in your account. You must submit a new redemption request if you wish to redeem those shares that were not yet Collected Shares at the time the original redemption request was received by the Fund.

Other Redemption Rules You Should Know

■

Once the Transfer Agent or your financial intermediary receives your redemption order in “good form,” your shares will be sold at the Fund’s next calculated NAV per share (i.e., the trade date). Any applicable CDSC will be deducted from the amount you're selling and the balance will be remitted to you.

■	Once the Fund receives your redemption request in “good form,” you cannot cancel it after the market closes.

■

If you sell your shares that are held in a Direct-at-Fund Account, we will normally send the redemption proceeds by mail or electronically transfer them to your bank account the next business day after the trade date. Note that your bank may take up to three business days to post an electronic funds transfer from your account.

■	If you sell your shares through a financial intermediary, the Funds will normally send the redemption proceeds to your financial intermediary within two business days after the trade date.

■	No interest will be paid on uncashed redemption checks.

■	Other restrictions may apply to retirement accounts. For information about these restrictions, contact your retirement plan administrator.

■	For broker-dealer and wrap fee accounts: The Fund reserves the right to redeem your shares if your account falls below the Fund's minimum initial investment requirement. The Fund will notify your broker-dealer prior to redeeming shares, and will provide details on how to avoid such redemption.

Prospectus 2018

65

Columbia Bond Fund

Buying, Selling and Exchanging Shares (continued)

■	Also keep in mind the Funds' Small Account Policy, which is described above in Buying, Selling and Exchanging Shares — Transaction Rules and Policies.

Exchanging Shares

Except for Class T shares, which are not exchangeable for another share class of any Fund (including with Class T shares of another Fund), you can generally sell shares of your Fund to buy shares of another Fund (subject to eligibility requirements), in what is called an exchange. You should read the prospectus of, and make sure you understand the investment objective, principal investment strategies, risks, fees and expenses of, the Fund into which you are exchanging. Although the Funds allow certain exchanges from one share class to another share class with higher expenses, you should consider the expenses of each class before making such an exchange. Please see Same-Fund Exchange Privilege below for more information.

You will be subject to a sales charge if, in a Direct-at-Fund Account, you exchange shares that have not previously paid a sales charge, including from Columbia Government Money Market Fund, Columbia Large Cap Enhanced Core Fund, Columbia Large Cap Index Fund, Columbia Mid Cap Index Fund, Columbia Small Cap Index Fund, Columbia U.S. Treasury Index Fund or any other Columbia Fund that does not charge a front-end sales charge, into a Columbia Fund that does assess a sales charge. If you hold your Fund shares through certain financial intermediaries, you may have limited exchangeability among the Funds. Please contact your financial intermediary for more information.

Systematic Exchanges

You may buy Class A, Class C, Class Inst, Class Inst3 and Class V shares of a Fund by exchanging each month from another Fund for shares of the same class of the Fund at no additional cost, subject to the following exchange amount minimums: $50 each month for individual retirement accounts (i.e., tax qualified accounts); and $100 each month for non-retirement accounts. Contact the Transfer Agent or your financial intermediary to set up the plan.

Exchanges will continue as long as your balance in the Fund you are exchanging shares from is sufficient to complete the systematic monthly exchange, subject to the Funds' Small Account Policy described above in Buying, Selling and Exchanging Shares — Transaction Rules and Policies. You may terminate the program or change the amount you would like to exchange (subject to the $50 and $100 minimum requirements noted immediately above) by calling the Transfer Agent at 800.345.6611.

Other Exchange Rules You Should Know

■	Exchanges are made at the NAV next calculated (plus any applicable sales charge) after your exchange order is received in “good form” (i.e., the trade date).

■	Once the Fund receives your exchange request in “good form,” you cannot cancel it after the market closes.

■	The rules for buying shares of a Fund generally apply to exchanges into that Fund, including, if your exchange creates a new Fund account, it must satisfy the minimum investment amount, unless a waiver applies.

■	Shares of the purchased Fund may not be used on the same day for another exchange or sale.

■

If you exchange shares from Class A shares of Columbia Government Money Market Fund to a non-money market Fund, any further exchanges must be between shares of the same class. For example, if you exchange from Class A shares of Columbia Government Money Market Fund into Class C shares of a non-money market Fund, you may not exchange from Class C shares of that non-money market Fund back to Class A shares of Columbia Government Money Market Fund or Class A shares of any other Fund.

■

A sales charge may apply when you exchange shares of a Fund that were not assessed a sales charge at the time you purchased such shares. If you invest through a Direct-at-Fund Account in Columbia Government Money Market Fund, Columbia Large Cap Enhanced Core Fund, Columbia Large Cap Index Fund, Columbia Mid Cap Index Fund, Columbia Small Cap Index Fund, Columbia U.S. Treasury Index Fund or any other Columbia Fund that does not impose a front-end sales charge and then you exchange into a Fund that does assess a sales charge, your transaction is subject to a front-end sales charge if you exchange into Class A shares and to a CDSC if you exchange into Class C shares of the Columbia Funds.

66	Prospectus 2018

Columbia Bond Fund

Buying, Selling and Exchanging Shares (continued)

■

If you purchased Class A shares of a Columbia Fund that imposes a front-end sales charge (and you paid any applicable sales charge) and you then exchange those shares into Columbia Government Money Market Fund, Columbia Large Cap Enhanced Core Fund, Columbia Large Cap Index Fund, Columbia Mid Cap Index Fund, Columbia Small Cap Index Fund, Columbia U.S. Treasury Index Fund or any other Columbia Fund that does not impose a front-end sales charge, you may exchange that amount to Class A of another Fund in the future, including dividends earned on that amount, without paying a sales charge.

■

If your shares are subject to a CDSC, you will not be charged a CDSC upon the exchange of those shares. Any CDSC will be deducted when you sell the shares you received from the exchange. The CDSC imposed at that time will be based on the period that begins when you bought shares of the original Fund and ends when you sell the shares of the Fund you received from the exchange. Any applicable CDSC charged will be the CDSC of the original Fund.

■	You may make exchanges only into a Fund that is legally offered and sold in your state of residence. Contact the Transfer Agent or your financial intermediary for more information.

■	You generally may make an exchange only into a Fund that is accepting investments.

■	The Fund may change or cancel your right to make an exchange by giving the amount of notice required by regulatory authorities (generally 60 days for a material change or cancellation).

■	Unless your account is part of a tax-advantaged arrangement, an exchange for shares of another Fund is a taxable event, and you may recognize a gain or loss for tax purposes.

■	Changing your investment to a different Fund will be treated as a sale and purchase, and you will be subject to applicable taxes on the sale and sales charges on the purchase of the new Fund.

■

Class Inst shares of a Fund may be exchanged for Class A or Class Inst shares of another Fund. In certain circumstances, the front-end sales charge applicable to Class A shares may be waived on exchanges of Class Inst shares for Class A shares. See Buying, Selling and Exchanging Shares — Buying Shares — Eligible Investors — Class Inst Shares for details.

■	You may generally exchange Class V shares of a Fund for Class A shares of another Fund if the other Fund does not offer Class V shares. Class V shares exchanged into Class A shares cannot be exchanged back into Class V shares.

Same-Fund Exchange Privilege

Shareholders may be eligible to invest in other classes of shares of the same Fund, and may exchange their current shares for another share class if deemed eligible and offered by the Fund. Such same-Fund exchanges could include an exchange of one class for another with higher expenses. Before making such an exchange, you should consider the expenses of each class. Shareholders should contact their financial intermediaries to learn more about the details of the same-Fund exchange privilege. Exchanges out of Class A, Class C and Class V shares will be subject to any applicable CDSC. Financial intermediaries that have a customized arrangement with regard to CDSCs are detailed in Appendix A .

Exchanges out of Class C shares to another share class of the same Fund are not permissible on Direct-at-Fund Accounts. Exchanges out of Class C shares to another share class of the same Fund within commissionable brokerage accounts are permitted only (1) by shareholders moving from a commissionable brokerage account to a fee-based advisory program or (2) when the exchange is part of a share class conversion (or a similar multiple shareholder transaction event) instituted by a financial intermediary and such conversion or similar type event is preapproved by the Distributor.

Ordinarily, shareholders will not recognize a gain or loss for U.S. federal income tax purposes upon a same-Fund exchange. You should consult your tax advisor about your particular exchanges.

Prospectus 2018

67

Columbia Bond Fund

Columbia Bond Fund

Distributions and Taxes (continued)

“buying a dividend.” To avoid “buying a dividend,” before you invest check the Fund's distribution schedule, which is available at the Funds' website and/or by calling the Funds' telephone number listed at the beginning of the section entitled Choosing a Share Class .

Taxes

You should be aware of the following considerations applicable to the Fund:

■

The Fund intends to qualify and to be eligible for treatment each year as a regulated investment company. A regulated investment company generally is not subject to tax at the fund level on income and gains from investments that are distributed to shareholders. However, the Fund's failure to qualify for treatment as a regulated investment company would result in Fund-level taxation, and consequently, a reduction in income available for distribution to you and in the NAV of your shares. Even if the Fund qualifies for treatment as a regulated investment company, the Fund may be subject to federal excise tax on certain undistributed income or gains.

■

Otherwise taxable distributions generally are taxable to you when paid, whether they are paid in cash or automatically reinvested in additional Fund shares. Dividends paid in January are deemed paid on December 31 of the prior year if the dividend was declared and payable to shareholders of record in October, November, or December of such prior year.

■

Distributions of the Fund's ordinary income and net short-term capital gain, if any, generally are taxable to you as ordinary income. Distributions of the Fund's net long-term capital gain, if any, generally are taxable to you as long-term capital gain. Whether capital gains are long-term or short-term is determined by how long the Fund has owned the investments that generated them, rather than how long you have owned your shares. The Fund expects that distributions will consist primarily of ordinary income.

■

From time to time, a distribution from the Fund could constitute a return of capital, which is not taxable to you so long as the amount of the distribution does not exceed your tax basis in your Fund shares. A return of capital reduces your tax basis in your Fund shares, with any amounts exceeding such basis generally taxable as capital gain.

■

If you are an individual and you meet certain holding period and other requirements for your Fund shares, a portion of your distributions may be treated as “qualified dividend income” taxable at the lower net long-term capital gain rates instead of the higher ordinary income rates. Qualified dividend income is income attributable to the Fund's dividends received from certain U.S. and foreign corporations, as long as the Fund meets certain holding period and other requirements for the stock producing such dividends. The Fund does not expect a significant portion of Fund distributions to be eligible for treatment as qualified dividend income.

■	Certain high-income individuals (as well as estates and trusts) are subject to a 3.8% tax on net investment income. For individuals, the 3.8% tax applies to the lesser of (1) the amount (if any) by which the taxpayer's modified adjusted gross income exceeds certain threshold amounts or (2) the taxpayer's “net investment income.”
	Net investment income generally includes for this purpose dividends, including any capital gain dividends, paid by the Fund, and net gains recognized on the sale, redemption or exchange of shares of the Fund.

■

Certain derivative instruments when held in the Fund's portfolio subject the Fund to special tax rules, the effect of which may be to, among other things, accelerate income to the Fund, defer Fund losses, cause adjustments in the holding periods of Fund portfolio securities, or convert capital gains into ordinary income, short-term capital losses into long-term capital losses or long-term capital gains into short-term capital gains. These rules could therefore affect the amount, timing and/or character of distributions to shareholders.

■

Generally, a Fund realizes a capital gain or loss on an option when the option expires, or when it is exercised, sold or otherwise terminated. However, if an option is a “section 1256 contract,” which includes most traded options on a broad-based index, and the Fund holds such option at the end of its taxable year, the Fund is deemed to sell such option at fair market value at such time and recognize any gain or loss thereon, which is generally deemed to be 60% long-term and 40% short-term capital gain or loss, as described further in the SAI.

Prospectus 2018

69

Columbia Bond Fund

Distributions and Taxes (continued)

■

Income and proceeds received by the Fund from sources within foreign countries may be subject to foreign taxes. If at the end of the taxable year more than 50% of the value of the Fund's assets consists of securities of foreign corporations, and the Fund makes a special election, you will generally be required to include in your income for U.S. federal income tax purposes your share of the qualifying foreign income taxes paid by the Fund in respect of its foreign portfolio securities. You may be able to claim a foreign tax credit or deduction in respect of this amount, subject to certain limitations. There is no assurance that the Fund will make this election for a taxable year, even if it is eligible to do so.

■

A sale, redemption or exchange of Fund shares is a taxable event. This includes redemptions where you are paid in securities. Your sales, redemptions and exchanges of Fund shares (including those paid in securities) usually will result in a taxable capital gain or loss to you, equal to the difference between the amount you receive for your shares (or are deemed to have received in the case of exchanges) and your adjusted tax basis in the shares, which is generally the amount you paid (or are deemed to have paid in the case of exchanges) for them. Any such capital gain or loss generally will be long-term capital gain or loss if you have held your Fund shares for more than one year at the time of sale or exchange. In certain circumstances, capital losses may be converted from short-term to long-term; in other circumstances, capital losses may be disallowed under the “wash sale” rules.

■

For sales, redemptions and exchanges of shares that were acquired in a non-qualified account after 2011, the Fund generally is required to report to shareholders and the Internal Revenue Service (IRS) cost basis information with respect to those shares. The Fund uses average cost basis as its default method of calculating cost basis. For more information regarding average cost basis reporting, other available cost basis methods, and selecting or changing to a different cost basis method, please see the SAI, columbiathreadneedleus.com, or contact the Fund at 800.345.6611. If you hold Fund shares through a financial intermediary (e.g., a brokerage firm), you should contact your financial intermediary to learn about its cost basis reporting default method and the reporting elections available to your account.

■

The Fund is required by federal law to withhold tax on any taxable or tax-exempt distributions and redemption proceeds paid to you (including amounts paid to you in securities and amounts deemed to be paid to you upon an exchange of shares) if: you have not provided a correct TIN or have not certified to the Fund that withholding does not apply, the IRS has notified us that the TIN listed on your account is incorrect according to its records, or the IRS informs the Fund that you are otherwise subject to backup withholding.

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Columbia Bond Fund

72	Prospectus 2018

Prospectus 2018

73

Prospectus 2018

75

Columbia Bond Fund

Appendix A: Financial Intermediary-Specific Reductions/Waivers of Sales Charges

As noted in the Choosing a Share Class section of the prospectus, the sales charge reductions and waivers available to investors who purchase and hold their Fund shares through different financial intermediaries may vary. This Appendix A describes financial intermediary-specific reductions and/or waiver policies applicable to Fund shares purchased and held through the particular financial intermediary. A reduction and/or waiver that is specific to a particular financial intermediary is not available to Direct-at-Fund Accounts or through another financial intermediary. These reductions and/or waivers may apply to purchases, sales, and exchanges of Fund shares. A shareholder transacting in Fund shares through a financial intermediary identified below should carefully read the terms and conditions of the reductions and/or waivers. Please consult your financial intermediary with respect to any sales charge reduction/waiver described below.

The financial intermediary-specific information below may be provided by, or compiled from or based on, information provided by the financial intermediaries noted. The Funds, the Investment Manager and the Distributor do not establish these financial intermediary-specific policies and are not responsible for ensuring that you receive any discounts or waivers that may be available to you.

The following information has been provided by Ameriprise Financial Services:

Class A Shares Front-End Sales Charge Waivers Available at Ameriprise Financial Services:

The following information applies to Class A shares purchases if you have an account with or otherwise purchase Fund shares through Ameriprise Financial Services:

Effective June 1, 2018, shareholders purchasing Fund shares through an Ameriprise Financial Services platform or account will be eligible for the following front-end sales charge waivers and discounts, which may differ from those disclosed elsewhere in the Fund’s prospectus or SAI:

■	Employer-sponsored retirement plans (e.g., 401(k) plans, 457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase pension plans and defined benefit plans). For purposes of this provision, employer-sponsored retirement plans do not include SEP IRAs, Simple IRAs or SAR-SEPs.
■	Shares purchased through an Ameriprise Financial Services investment advisory program (if an Advisory or similar share class for such investment advisory program is not available).
■	Shares purchased by third party investment advisors on behalf of their advisory clients through Ameriprise Financial Services’ platform (if an Advisory or similar share class for such investment advisory program is not available).
■	Shares purchased through reinvestment of dividends and capital gain distributions when purchasing shares of the same Fund (but not any other fund within the same fund family).
■	Shares exchanged from Class C shares of the same fund in the month of or following the 10-year anniversary of the purchase date. To the extent that this prospectus elsewhere provides for a waiver with respect to such shares following a shorter holding period, that waiver will apply to exchanges following such shorter period. To the extent that this prospectus elsewhere provides for a waiver with respect to exchanges of Class C shares for load waived shares, that waiver will also apply to such exchanges.
■	Employees and registered representatives of Ameriprise Financial Services or its affiliates and their immediate family members.
■	Shares purchased by or through qualified accounts (including IRAs, Coverdell Education Savings Accounts,  401(k)s, 403(b) TSCAs subject to ERISA and defined benefit plans) that are held by a covered family member, defined as an Ameriprise financial advisor and/or the advisor’s spouse, advisor’s lineal ascendant (mother, father, grandmother, grandfather, great grandmother, great grandfather), advisor’s lineal descendant (son, step-son, daughter, step-daughter, grandson, granddaughter, great grandson, great granddaughter) or any spouse of a covered family member who is a lineal descendant.

A-1	Prospectus 2018

Columbia Bond Fund

Appendix A: Financial Intermediary-Specific Reductions/Waivers of Sales Charges (continued)

■

Shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within 90 days following the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a front-end or deferred sales load (i.e., rights of reinstatement).

The following information has been provided by Merrill Lynch:

Shareholders purchasing Fund shares through a Merrill Lynch platform or account are eligible for the following sales charge waivers and discounts, which may differ from those disclosed elsewhere in the Fund’s prospectus or SAI:

Class A Shares Front-End Sales Charge Discounts:

Merrill Lynch makes available breakpoint discounts on Class A shares of the Fund through:

■

Rights of Accumulation (ROA) which entitle shareholders to breakpoint discounts will be automatically calculated based on the aggregated holding of fund family assets held by accounts within the purchaser’s household at Merrill Lynch. Eligible fund family assets not held at Merrill Lynch may be included in the ROA calculation only if the shareholder notifies his or her financial advisor about such assets.

■

Letters of Intent (LOI) which allow for breakpoint discounts based on anticipated purchases within a fund family, through Merrill Lynch, over a 13-month period of time (if applicable).

Class A Shares Front-End Sales Charge Waivers:

■	Employer-sponsored retirement, deferred compensation and employee benefit plans (including health savings accounts) and trusts used to fund those plans, provided that the plan is a group plan (more than one participant), the shares are not held in a commission-based brokerage account and shares are held in the name of the plan through an omnibus account
■	Shares purchased by or through a 529 Plan
■	Shares purchased through a Merrill Lynch affiliated investment advisory program
■	Shares purchased by third party investment advisors on behalf of their advisory clients through Merrill Lynch’s platform
■	Shares of funds purchased through the Merrill Edge Self-Directed platform
■	Shares purchased through reinvestment of capital gains distributions and dividend reinvestment when purchasing shares of the same Fund (but not any other fund within the same fund family)
■	Shares exchanged from Class C (i.e., level-load) shares of the same fund in the month of or following the 10-year anniversary of the purchase date
■	Employees and registered representatives of Merrill Lynch or its affiliates and their family members
■	Directors or Trustees of the Fund, and employees of the Fund’s investment adviser or any of its affiliates, as described in this prospectus

■

Shares purchased from the proceeds of redemptions within the same fund family, provided (1) the repurchase occurs within 90 days following the redemption, (2) the redemption and purchase occur in the same account, and (3) redeemed shares were subject to a front-end or deferred sales load (known as Rights of Reinstatement).

CDSC Waivers on Class A and C Shares:

■	Shares redeemed following the death or disability of the shareholder
■	Shares sold as part of a systematic withdrawal plan as described in this prospectus
■	Redemptions that constitute a return of excess contributions from an IRA
■	Shares sold as part of a required minimum distribution for IRA and retirement accounts due to the shareholder reaching age 70½

Prospectus 2018

A-2

Columbia Bond Fund

Appendix A: Financial Intermediary-Specific Reductions/Waivers of Sales Charges (continued)

■	Shares sold to pay Merrill Lynch fees but only if the transaction is initiated by Merrill Lynch
■	There will be no CDSC charged on the sale of Fund shares acquired through a right of reinstatement

■	The redemption of shares held in retirement brokerage accounts, that are exchanged for a lower cost share class due to transfer to a fee based account or platform (applicable to Class A and Class C shares only).

The following information has been provided by Morgan Stanley Wealth Management:

Effective July 1, 2018, shareholders purchasing Fund shares through a Morgan Stanley Wealth Management transactional brokerage account will be eligible only for the following front-end sales charge waivers with respect to Class A shares, which may differ from and may be more limited than those disclosed elsewhere in the Fund’s Prospectus or SAI.

Front-end Sales Charge Waivers on Class A Shares available at Morgan Stanley Wealth Management Effective July 1, 2018:

■	Employer-sponsored retirement plans (e.g., 401(k) plans, 457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase pension plans and defined benefit plans).  For purposes of this provision, employer-sponsored retirement plans do not include SEP IRAs, Simple IRAs, SAR-SEPs or Keogh plans
■	Morgan Stanley employee and employee-related accounts according to Morgan Stanley’s account linking rules
■	Shares purchased through reinvestment of dividends and capital gains distributions when purchasing shares of the same fund
■	Shares purchased through a Morgan Stanley self-directed brokerage account
■	Class C (i.e., level-load) shares that are no longer subject to a contingent deferred sales charge and are converted to Class A shares of the same fund pursuant to Morgan Stanley Wealth Management’s share class conversion program
■	Shares purchased from the proceeds of redemptions within the same fund family, provided (i) the repurchase occurs within 90 days following the redemption, (ii) the redemption and purchase occur in the same account, and (iii) redeemed shares were subject to a front-end or deferred sales charge.

Class T Shares Front-End Sales Charge Waivers Available Through a Transactional Brokerage Account:

■	Employer-sponsored retirement plans (e.g., 401(k) plans, 457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase pension plans and defined benefit plans). For purposes of this provision, employer-sponsored retirement plans do not include SEP IRAs, Simple IRAs, SAR-SEPs or Keogh plans; however these plans are eligible to purchase Class T shares through a transactional brokerage account.
■	Morgan Stanley Wealth Management employee and employee-related accounts according to Morgan Stanley’s account linking rules.
■	Mutual fund shares exchanged from an existing position in the same fund as part of a share class conversion instituted by Morgan Stanley Wealth Management.

A-3	Prospectus 2018

Columbia Bond Fund

Appendix A: Financial Intermediary-Specific Reductions/Waivers of Sales Charges (continued)

Shareholders purchasing Fund shares through a platform or account of RBC Capital Markets, LLC are eligible for the following sales charge waiver:

Class A Shares Front-End Sales Charge Waiver:

■

For employer-sponsored retirement plans held through a commissionable brokerage account, Class A shares are available at NAV (i.e., without a sales charge). For this purpose, employer-sponsored retirement plans include, but are not limited to, 401(k) plans, 457 plans, employer-sponsored 403(b) plans, profit sharing and money purchase pension plans and defined benefit plans. For purposes of this provision, employer-sponsored retirement plans do not include SEP IRAs, Simple IRAs, SAR-SEPs or Keogh plans.

Prospectus 2018

A-4

Columbia Bond Fund

P.O. Box 8081
Boston, MA 02266-8081

Columbia Corporate Income Fund

Summary of the Fund

Columbia Corporate Income Fund

Summary of the Fund (continued)

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example illustrates the hypothetical expenses that you would incur over the time periods indicated, and assumes that:

■	you invest $10,000 in the applicable class of Fund shares for the periods indicated,
■	your investment has a 5% return each year, and
■	the Fund’s total annual operating expenses remain the same as shown in the Annual Fund Operating Expenses table above.

Since the waivers and/or reimbursements shown in the Annual Fund Operating Expenses table above expire as indicated in the preceding table, they are only reflected in the 1 year example and the first year of the other examples. Although your actual costs may be higher or lower, based on the assumptions listed above, your costs would be:

    

Portfolio Turnover

The Fund may pay transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 78% of the average value of its portfolio.

Principal Investment Strategies

Under normal circumstances, the Fund invests at least 80% of its net assets (including the amount of any borrowings for investment purposes) in debt securities issued by corporate and other non-governmental issuers, including dollar-denominated debt securities issued by foreign companies. The Fund also invests at least 60% of total assets in securities that, at the time of purchase, are investment grade securities or in unrated securities determined to be of comparable quality. The Fund may invest up to 25% of its total assets in debt instruments that, at the time of purchase, are rated below investment grade or are unrated but determined to be of comparable quality (commonly referred to as “high-yield” investments or “junk” bonds). Under normal circumstances, the Fund’s average effective duration will be between three and ten years.

The Fund may invest in derivatives, such as futures (including interest rate futures), for hedging and non-hedging purposes.

The Fund may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis.

The Fund may invest in privately placed and other securities or instruments that are purchased and sold pursuant to Rule 144A or other exemptions under the Securities Act of 1933, as amended, subject to liquidity determinations and certain regulatory restrictions.

The Fund may invest in U.S. Government obligations, asset-backed securities and mortgage-backed securities.

4	Prospectus 2018

Columbia Corporate Income Fund

Summary of the Fund (continued)

Columbia Corporate Income Fund

Summary of the Fund (continued)

Derivatives Risk – Futures Contracts Risk. A futures contract is an exchange-traded derivative transaction between two parties in which a buyer (holding the “long” position) agrees to pay a fixed price (or rate) at a specified future date for delivery of an underlying reference from a seller (holding the “short” position). The seller hopes that the market price on the delivery date is less than the agreed upon price, while the buyer hopes for the contrary. Certain futures contract markets are highly volatile, and futures contracts may be illiquid. Futures exchanges may limit fluctuations in futures contract prices by imposing a maximum permissible daily price movement. The Fund may be disadvantaged if it is prohibited from executing a trade outside the daily permissible price movement. At or prior to maturity of a futures contract, the Fund may enter into an offsetting contract and may incur a loss to the extent there has been adverse movement in futures contract prices. The liquidity of the futures markets depends on participants entering into offsetting transactions rather than making or taking delivery. To the extent participants make or take delivery, liquidity in the futures market could be reduced. Because of the low margin deposits normally required in futures trading, it is possible that the Fund may employ a high degree of leverage in the portfolio. As a result, a relatively small price movement in a futures contract may result in substantial losses to the Fund, exceeding the amount of the margin paid. For certain types of futures contracts, losses are potentially unlimited. Futures markets are highly volatile and the use of futures may increase the volatility of the Fund’s NAV. Futures contracts executed (if any) on foreign exchanges may not provide the same protection as U.S. exchanges. Futures contracts can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk, foreign currency risk and interest rate risk, while also exposing the Fund to correlation risk, counterparty risk, hedging risk, leverage risk, liquidity risk, pricing risk and volatility risk.

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. Foreign securities subject the Fund to the risks associated with investing in the particular country of an issuer, including political, regulatory, economic, social, diplomatic and other conditions or events (including, for example, military confrontations, war and terrorism), occurring in the country or region, as well as risks associated with less developed custody and settlement practices. Foreign securities may be more volatile and less liquid than securities of U.S. companies, and are subject to the risks associated with potential imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities. The performance of the Fund may also be negatively affected by fluctuations in a foreign currency's strength or weakness relative to the U.S. dollar, particularly to the extent the Fund invests a significant percentage of its assets in foreign securities or other assets denominated in currencies other than the U.S. dollar.

High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality expose the Fund to a greater risk of loss of principal and income than a fund that invests solely or primarily in investment grade debt instruments. In addition, these investments have greater price fluctuations, are less liquid and are more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal.

Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if prevailing interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk. Similarly, a period of rising interest rates may negatively impact the Fund’s performance. Actions by governments and central banking authorities can result in increases in interest rates. Such actions may negatively affect the value of debt instruments held by the

6	Prospectus 2018

Columbia Corporate Income Fund

Summary of the Fund (continued)

Fund, resulting in a negative impact on the Fund's performance and NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which would negatively affect the Fund’s performance. Poor performance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors.

Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Decreases in the number of financial institutions, including banks and broker-dealers, willing to make markets (match up sellers and buyers) in the Fund’s investments or decreases in their capacity or willingness to trade such investments may increase the Fund’s exposure to this risk. The debt market has experienced considerable growth, and financial institutions making markets in instruments purchased and sold by the Fund (e.g., bond dealers) have been subject to increased regulation. The impact of that growth and regulation on the ability and willingness of financial institutions to engage in trading or “making a market” in such instruments remains unsettled. Certain types of investments, such as lower-rated securities or those that are purchased and sold in over-the-counter markets, may be especially subject to liquidity risk. Securities or other assets in which the Fund invests may be traded in the over-the-counter market rather than on an exchange and therefore may be more difficult to purchase or sell at a fair price, which may have a negative impact on the Fund’s performance. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. Certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market.

Market Risk. Market risk refers to the possibility that the market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. An investment in the Fund could lose money over short or long periods.

Mortgage- and Other Asset-Backed Securities Risk. The value of any mortgage-backed and other asset-backed securities held by the Fund may be affected by, among other things, changes or perceived changes in: interest rates; factors concerning the interests in and structure of the issuer or the originator of the mortgages or other assets; the creditworthiness of the entities that provide any supporting letters of credit, surety bonds or other credit enhancements; or the market's assessment of the quality of underlying assets. Payment of principal and interest on some mortgage-backed securities (but not the market value of the securities themselves) may be guaranteed by the full faith and credit of a particular U.S. Government agency, authority, enterprise or instrumentality, and some, but not all, are also insured or guaranteed by the U.S. Government. Mortgage-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) may entail greater risk than obligations guaranteed by the U.S. Government. Mortgage- and other asset-backed securities are subject to prepayment risk, which is the possibility that

Prospectus 2018

7

Columbia Corporate Income Fund

Summary of the Fund (continued)

the underlying mortgage or other asset may be refinanced or prepaid prior to maturity during periods of declining or low interest rates, causing the Fund to have to reinvest the money received in securities that have lower yields. Rising or high interest rates tend to extend the duration of mortgage- and other asset-backed securities, making their prices more volatile and more sensitive to changes in interest rates.

Prepayment and Extension Risk. Prepayment and extension risk is the risk that a bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. In the case of mortgage- or other asset-backed securities, as interest rates decrease or spreads narrow, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in interest rates will extend the life of a mortgage- or asset-backed security beyond the prepayment time. If the Fund’s investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on securities with higher interest rates or wider spreads.

Reinvestment Risk. Reinvestment risk is the risk that the Fund will not be able to reinvest income or principal at the same return it is currently earning.

Rule 144A and Other Exempted Securities Risk. The Fund may invest in privately placed and other securities or instruments exempt from SEC registration (collectively “private placements”), subject to liquidity and other regulatory restrictions. In the U.S. market, private placements are typically sold only to qualified institutional buyers, or qualified purchasers, as applicable. An insufficient number of buyers interested in purchasing private placements at a particular time could adversely affect the marketability of such investments and the Fund might be unable to dispose of them promptly or at reasonable prices, subjecting the Fund to liquidity risk. The Fund may invest in private placements determined to be liquid as well as those determined to be illiquid. Even if determined to be liquid, the Fund’s holdings of private placements may increase the level of Fund illiquidity if eligible buyers are unable or unwilling to purchase them at a particular time. Issuers of Rule 144A eligible securities are required to furnish information to potential investors upon request. However, the required disclosure is much less extensive than that required of public companies and is not publicly available since the offering is not filed with the SEC. Further, issuers of Rule 144A eligible securities can require recipients of the offering information (such as the Fund) to agree contractually to keep the information confidential, which could also adversely affect the Fund’s ability to dispose of the security.

U.S. Government Obligations Risk. While U.S. Treasury obligations are backed by the “full faith and credit” of the U.S. Government, such securities are nonetheless subject to credit risk (i.e., the risk that the U.S. Government may be, or be perceived to be, unable or unwilling to honor its financial obligations, such as making payments). Securities issued or guaranteed by federal agencies or authorities and U.S. Government-sponsored instrumentalities or enterprises may or may not be backed by the full faith and credit of the U.S. Government.

Performance Information

The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s Class A share performance (without sales charges) has varied for each full calendar year shown. If the sales charges were reflected, returns shown would be lower. The table below the bar chart compares the Fund’s returns (after applicable sales charges shown in the Shareholder Fees table in this prospectus) for the periods shown with a blended index that is intended to provide a measure of the Fund's performance given its investment strategy, as well as another measure of performance for markets in which the Fund may invest.

The performance of one or more share classes shown in the table below begins before the indicated inception date for such share class. The returns shown for each such share class include the returns of the Fund’s Class Inst shares (adjusted to reflect the higher class-related operating expenses of such classes, where applicable) for periods

8	Prospectus 2018

Columbia Corporate Income Fund

Summary of the Fund (continued)

prior to its inception date. Except for differences in annual returns resulting from differences in expenses and sales charges (where applicable), the share classes of the Fund would have substantially similar annual returns because all share classes of the Fund invest in the same portfolio of securities.

The after-tax returns shown in the Average Annual Total Returns table below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the table and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the table. In addition, the after-tax returns shown in the table do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs). The after-tax returns are shown only for Class A shares and will vary for other share classes.

The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 800.345.6611 or visiting columbiathreadneedleus.com.

    

Year by Year Total Return (%) as of December 31 Each Year*	Best and Worst Quarterly Returns During the Period Shown in the Bar Chart
	Best	2nd Quarter 2009	14.15%
	Worst	3rd Quarter 2008	-7.67%

*	Year to Date return as of June 30, 2018: -3.35%

  

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Columbia Corporate Income Fund

Summary of the Fund (continued)

Columbia Corporate Income Fund

Summary of the Fund (continued)

More information about these minimums can be found in the Buying, Selling and Exchanging Shares - Buying Shares section of the prospectus. There is no minimum additional investment for any share class.

Tax Information

The Fund normally distributes net investment income and net realized capital gains, if any, to shareholders. These distributions are generally taxable to you as ordinary income or capital gains, unless you are investing through a tax-advantaged account, such as a 401(k) plan or an IRA. If you are investing through a tax-advantaged account, you may be taxed upon withdrawals from that account.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies — including Columbia Management Investment Advisers, LLC (the Investment Manager), Columbia Management Investment Distributors, Inc. (the Distributor) and Columbia Management Investment Services Corp. (the Transfer Agent) — may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary’s website for more information.

Prospectus 2018

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Columbia Corporate Income Fund

More Information About the Fund

Columbia Corporate Income Fund

More Information About the Fund (continued)