Management

Investment adviser Capital Research and Management Company ^SM

Purchase and sale of fund shares The minimum amount to establish an account for all share classes is normally $1,000 and the minimum to add to an account is $50. For a payroll deduction retirement plan account, payroll deduction savings plan account or employer-sponsored 529 account, the minimum is $25 to establish or add to an account. For accounts with Class F-3 shares held and serviced by the fund’s transfer agent, the minimum investment amount is $1,000,000.

If you are a retail investor, you may sell (redeem) shares on any business day through your dealer or financial advisor or by writing to American Funds Service Company ^® at P.O. Box 6007, Indianapolis, Indiana 46206-6007; telephoning American Funds Service Company at (800) 421-4225; faxing American Funds Service Company at (888) 421-4351; or accessing our website at americanfunds.com. Please contact your plan administrator or recordkeeper to sell (redeem) shares from your retirement plan.

Tax information Dividends you receive from the fund are subject to federal income taxes and may also be subject to state and local taxes, unless you are tax-exempt or your account is tax-favored. Generally, redemptions, including exchanges, will not result in a capital gain or loss for federal or state income tax purposes.

Payments to broker-dealers and other financial intermediaries If you purchase shares of the fund through a broker-dealer or other financial intermediary (such as a bank), the fund and the fund’s distributor or its affiliates 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 individual financial advisor to recommend the fund over another investment. Ask your individual financial advisor or visit your financial intermediary’s website for more information.

American Funds U.S. Government Money Market Fund / Prospectus     8

Investment objective, strategies and risks The investment objective of the fund is to provide you with a way to earn income on your cash reserves while preserving capital and maintaining liquidity. While it has no present intention to do so, the fund’s board may change the fund’s objective without shareholder approval upon 60 days’ written notice to shareholders. The fund is a government money market fund that seeks to preserve the value of your investment at $1.00 per share.

The fund will invest at least 99.5% of its total assets in cash, U.S. Treasury securities and other government securities guaranteed or issued by an agency or instrumentality of the U.S. government, and repurchase agreements that are fully collateralized by cash or government securities. Additionally, at least 80% of the fund’s assets will normally be invested in securities that are issued or guaranteed by the U.S. government, its agencies and instrumentalities, and repurchase agreements that are fully collateralized by government securities.

Repurchase agreements are agreements under which the fund purchases a security from a bank or broker-dealer and obtains a simultaneous commitment from the seller to repurchase the security at a specified time and price. Because the security purchased by the fund constitutes collateral for the seller’s repurchase obligation, a repurchase agreement is effectively a loan by the fund that is collateralized by the security purchased. The fund will only enter into repurchase agreements involving securities of the type (excluding any maturity limitations) in which it could otherwise invest. In practice, the fund expects to enter only into repurchase agreements that are fully collateralized by cash or U.S. government securities.

In accordance with applicable rules and regulations relating to money market funds, the fund will maintain a dollar-weighted average maturity of 60 days or less and its dollar-weighted average life will not exceed 120 days. Additionally, the fund will hold at least 10% of its total assets in daily liquid assets and at least 30% of its total assets in weekly liquid assets. For purposes of these limits, daily liquid assets and weekly liquid assets are generally defined to include cash, U.S. Treasuries, certain other government securities, as well as other securities that can be readily converted to cash within one or five business days, respectively.

The following are principal risks associated with the fund’s investment strategies.

Market conditions — The prices of, and the income generated by, the securities held by the fund may decline – sometimes rapidly or unpredictably – due to various factors, including events or conditions affecting the general economy or particular industries; overall market changes; local, regional or global political, social or economic instability; governmental or governmental agency responses to economic conditions; and currency exchange rate, interest rate and commodity price fluctuations.

Investing in securities backed by the U.S. government — Securities backed by the U.S. Treasury or the full faith and credit of the U.S. government are guaranteed only as to the timely payment of interest and principal when held to maturity. Accordingly, the current market values for these securities will fluctuate with changes in interest rates. Securities issued by government-sponsored entities and federal agencies and instrumentalities that are not backed by the full faith and credit of the U.S. government are neither issued nor guaranteed by the U.S. government.

9     American Funds U.S. Government Money Market Fund / Prospectus

Interest rate risk — The values and liquidity of the securities held by the fund may be affected by changing interest rates. For example, the values of these securities may decline when interest rates rise and increase when interest rates fall. Longer maturity debt securities generally have greater sensitivity to changes in interest rates and may be subject to greater price fluctuations than shorter maturity debt securities. The fund may invest in variable and floating rate securities. Although the values of such securities are generally less sensitive to interest rate changes than those of other debt securities, the value of variable and floating rate securities may decline if their interest rates do not rise as quickly, or as much, as general interest rates. Conversely, floating rate securities will not generally increase in value if interest rates decline. During periods of extremely low short-term interest rates, the fund may not be able to maintain a positive yield and, given the current historically low interest rate environment, risks associated with rising rates are currently heightened.

Investing in repurchase agreements — Upon entering into a repurchase agreement, the fund purchases a security from a bank or broker-dealer, which simultaneously commits to repurchase the security within a specified time at the fund’s cost with interest. The security purchased by the fund constitutes collateral for the seller’s repurchase obligation. If the party agreeing to repurchase should default, the fund may seek to sell the security it holds as collateral. The fund may incur a loss if the value of the collateral securing the repurchase obligation falls below the repurchase price. The fund may also incur disposition costs and encounter procedural delays in connection with liquidating the collateral.

Management — The investment adviser to the fund actively manages the fund’s investments. Consequently, the fund is subject to the risk that the methods and analyses employed by the investment adviser in this process may not produce the desired results.

The following are certain additional risks associated with the fund’s investment strategies.

Exposure to country, region, industry or sector — Subject to the fund’s investment limitations, the fund may have significant exposure to a particular country, region, industry or sector. Such exposure may cause the fund to be more impacted by risks relating to the country, region, industry or sector than a fund without such levels of exposure. For example, if the fund has significant exposure in a particular country, then social, economic, regulatory or other issues that negatively affect that country may have a greater impact on the fund than on a fund that is more geographically diversified.

In addition to the principal investment strategies described above, the fund has other investment practices that are described in the statement of additional information, which includes a description of other risks related to the fund’s principal investment strategies and other investment practices. The fund’s investment results will depend on the ability of the fund’s investment adviser to navigate the risks discussed above as well as those described in the statement of additional information.

American Funds U.S. Government Money Market Fund / Prospectus     10

Fund comparative indexes The investment results table in this prospectus shows how the fund’s average annual total returns compare with various broad measures of market results. USTREAS T-Bill Auction Ave 3 Mon is an index that measures the performance of the average investment rate of U.S. Treasury bills (T-Bills) with a three-month maturity. Three-month T-Bills are short-term securities issued by the U.S. government that are generally considered to be risk-free. In calculating index results, Morningstar, the index provider, determines the arithmetic mean of the investment rates on all three-month T-Bills issued during a given month as reported by the U.S. Treasury’s Bureau of the Public Debt. The investment rate is then converted into a price and a monthly return, assuming that the T-Bill is held to maturity. This index is unmanaged, and its results include reinvested dividends and/or distributions but do not reflect the effect of sales charges, commissions, account fees, expenses or U.S. federal income taxes. The Lipper U.S. Government Money Market Funds Average is composed of funds that invest principally in financial instruments issued or guaranteed by the U.S. government, its agencies, or its instrumentalities, with dollar-weighted average maturities of less than 90 days. These funds seek to maintain a constant net asset value. The results of the underlying funds in the average include reinvestment of dividends and capital gain distributions, as well as brokerage commissions paid by the funds for portfolio transactions and other fund expenses, but do not reflect the effect of sales charges, account fees or U.S. federal income taxes.

Fund results All fund results in this prospectus reflect the reinvestment of dividends and capital gain distributions, if any. Unless otherwise noted, fund results reflect any fee waivers and/or expense reimbursements in effect during the periods presented.

11     American Funds U.S. Government Money Market Fund / Prospectus

Management and organization

Investment adviser Capital Research and Management Company, an experienced investment management organization founded in 1931, serves as the investment adviser to the fund and other funds, including the American Funds. Capital Research and Management Company is a wholly owned subsidiary of The Capital Group Companies, Inc. and is located at 333 South Hope Street, Los Angeles, California 90071. Capital Research and Management Company manages the investment portfolio and business affairs of the fund. The total management fee paid by the fund to its investment adviser for the most recent fiscal year, as a percentage of average net assets, appears in the Annual Fund Operating Expenses table under “Fees and expenses of the fund.” A more detailed description of the Investment Advisory and Service Agreement between the fund and the investment adviser is included in the fund’s statement of additional information, and a discussion regarding the basis for approval by the fund’s board of trustees is contained in the fund’s semi-annual report to shareholders for the period ended March 31, 2018.

Capital Research and Management Company manages equity assets through three equity investment divisions and fixed-income assets through its fixed-income investment division, Capital Fixed Income Investors. The three equity investment divisions — Capital World Investors, Capital Research Global Investors and Capital International Investors — make investment decisions independently of one another.

The equity investment divisions may, in the future, be incorporated as wholly owned subsidiaries of Capital Research and Management Company. In that event, Capital Research and Management Company would continue to be the investment adviser, and day-to-day investment management of equity assets would continue to be carried out through one or more of these subsidiaries. Although not currently contemplated, Capital Research and Management Company could incorporate its fixed-income investment division in the future and engage it to provide day-to-day investment management of fixed-income assets. Capital Research and Management Company and each of the funds it advises have received an exemptive order from the U.S. Securities and Exchange Commission that allows Capital Research and Management Company to use, upon approval of the fund’s board, its management subsidiaries and affiliates to provide day-to-day investment management services to the fund, including making changes to the management subsidiaries and affiliates providing such services. The fund’s shareholders have approved this arrangement; however, there is no assurance that Capital Research and Management Company will incorporate its investment divisions or exercise any authority granted to it under the exemptive order.

Portfolio holdings Portfolio holdings information for the fund is available on the American Funds website at americanfunds.com. A description of the fund’s policies and procedures regarding disclosure of information about its portfolio holdings is available in the statement of additional information.

American Funds U.S. Government Money Market Fund / Prospectus     12

Certain privileges and/or services described on the following pages of this prospectus and in the statement of additional information may not be available to you, depending on your investment dealer or retirement plan recordkeeper. Please see your financial advisor, investment dealer or retirement plan recordkeeper for more information.

Shareholder information

Shareholder services American Funds Service Company, the fund’s transfer agent, offers a wide range of services that you can use to alter your investment program should your needs or circumstances change. These services may be terminated or modified at any time upon 60 days’ written notice.

A more detailed description of policies and services is included in the fund’s statement of additional information and the owner’s guide sent to new American Funds shareholders entitled Welcome . Class 529 and Class ABLE-A shareholders should also refer to the applicable program description for information on policies and services relating specifically to their account(s). These documents are available by writing to or calling American Funds Service Company.

13     American Funds U.S. Government Money Market Fund / Prospectus

Unless otherwise noted or unless the context requires otherwise, references on the following pages to (i) Class A shares also refer to Class 529-A and Class ABLE-A shares, (ii) Class C, T or F-1 shares also refer to the corresponding Class 529-C, 529-T or 529-F-1 shares, (iii) Class F shares refer to Class F-1, F-2 and F-3 shares and (iv) Class R shares refer to Class R-1, R-2, R-2E, R-3, R-4, R-5E, R-5 and R-6 shares.

Purchase, exchange and sale of shares The fund’s transfer agent, on behalf of the fund and American Funds Distributors , ^® the fund’s distributor, is required by law to obtain certain personal information from you or any other person(s) acting on your behalf in order to verify your or such person’s identity. If you do not provide the information, the transfer agent may not be able to open your account. If the transfer agent is unable to verify your identity or that of any other person(s) authorized to act on your behalf, or believes it has identified potentially criminal activity, the fund and American Funds Distributors reserve the right to close your account or take such other action they deem reasonable or required by law.

When purchasing shares, you should designate the fund or funds in which you wish to invest. Subject to the exception below, if no fund is designated, your money will be held uninvested (without liability to the transfer agent for loss of income or appreciation pending receipt of proper instructions) until investment instructions are received, but for no more than three business days. Your investment will be made at the net asset value (plus any applicable sales charge, in the case of Class A or Class T shares) next determined after investment instructions are received and accepted by the transfer agent. If investment instructions are not received, your money will be invested in Class A shares (or, if you are investing through a financial intermediary who offers only Class T shares, in Class T shares) of American Funds U.S. Government Money Market Fund on the third business day after receipt of your investment.

If the amount of your cash investment is $10,000 or less, no fund is designated, and you made a cash investment (excluding exchanges) within the last 16 months, your money will be invested in the same proportion and in the same fund or funds and in the same class of shares in which your last cash investment was made.

Different procedures may apply to certain employer-sponsored arrangements, including, but not limited to, SEPs and SIMPLE IRAs.

Valuing shares The net asset value of each share class of the fund is the value of a single share of that class. The fund seeks to preserve the net asset value of each share class at $1.00. The fund calculates the net asset value each day the New York Stock Exchange is open for trading as of approximately 4 p.m. New York time, the normal close of regular trading. If, for example, the New York Stock Exchange closes at 1 p.m. New York time, the fund’s net asset value would still be determined as of 4 p.m. New York time. In this example, portfolio securities traded on the New York Stock Exchange would be valued at their closing prices unless the investment adviser determines that a “fair value” adjustment is appropriate due to subsequent events. The fund may also calculate its share price on days the New York Stock Exchange is closed when deemed prudent to do so by the fund’s officers.

Assets are valued primarily on the basis of evaluated prices from third-party pricing services. However, the fund has adopted procedures for making fair value determinations if evaluated prices are not readily available or are not considered reliable.

American Funds U.S. Government Money Market Fund / Prospectus     14

The valuation of the fund’s portfolio securities and calculation of its net asset value are based upon the penny-rounding method of pricing pursuant to U.S. Securities and Exchange Commission regulations, which permit current net asset value per share to be rounded to the nearest cent, provided the fund follows certain maturity, credit quality and other guidelines. The fund follows standard industry practice by typically reflecting changes in its holdings of portfolio securities on the first business day following a portfolio trade.

Your shares will be purchased at the net asset value (plus any applicable sales charge, in the case of Class A or Class T shares) or sold at the net asset value next determined after American Funds Service Company receives your request, provided that your request contains all information and legal documentation necessary to process the transaction. A contingent deferred sales charge may apply at the time you sell certain Class C shares.

Purchase of Class A and T shares You may generally open an account and purchase Class A and T shares shares by contacting any financial advisor (who may impose transaction charges in addition to those described in this prospectus) authorized to sell the fund’s shares. You may purchase additional shares in various ways, including through your financial advisor and by mail, telephone, the Internet and bank wire.

Class C shares Class C shares of the fund may be acquired only by exchanging from Class C shares of other American Funds. Direct purchases of Class C shares of the fund are not permitted.

Automatic conversion of Class C and Class 529-C shares Class C shares automatically convert to Class F-1 shares and Class 529-C shares automatically convert to Class 529-A shares, in each case in the month of the 10-year anniversary of the purchase date. The Internal Revenue Service currently takes the position that such automatic conversions are not taxable. Should its position change, the automatic conversion feature may be suspended. If this were to happen, you would have the option of converting your Class C shares to Class F-1 shares or your Class 529-C shares to Class 529-A shares at the anniversary date described above. This exchange would be based on the relative net asset values of the two classes in question, without the imposition of a sales charge or fee, but you might face certain tax consequences as a result.

Purchase of Class F shares You may generally open an account and purchase Class F shares only through fee-based programs of investment dealers that have special agreements with the fund’s distributor, through financial intermediaries that have been approved by, and that have special agreements with, the fund’s distributor to offer Class F shares to self-directed investment brokerage accounts that may charge a transaction fee, through certain registered investment advisors and through other intermediaries approved by the fund’s distributor. These intermediaries typically charge ongoing fees for services they provide. Intermediary fees are not paid by the fund and normally range from .75% to 1.50% of assets annually, depending on the services offered.

Class F-2 and F-3 shares may also be available on brokerage platforms of firms that have agreements with the fund’s distributor to offer such shares solely when acting as an agent for the investor. An investor transacting in Class F-2 or F-3 shares in these programs may be required to pay a commission and/or other forms of compensation to the broker. Shares of the fund are available in other share classes that have different fees and expenses.

15     American Funds U.S. Government Money Market Fund / Prospectus

In addition, Class F-3 shares are available to institutional investors, which include, but are not limited to, charitable organizations, governmental institutions and corporations. For accounts held and serviced by the fund’s transfer agent the minimum investment amount is $1,000,000.

Purchase of Class 529 shares Class 529 shares may be purchased only through an account established with a 529 college savings plan managed by the American Funds organization. You may open this type of account and purchase Class 529 shares by contacting any financial advisor (who may impose transaction charges in addition to those described in this prospectus) authorized to sell such an account. You may purchase additional shares in various ways, including through your financial advisor and by mail, telephone, the Internet and bank wire.

Class 529-E shares may be purchased only by employees participating through an eligible employer plan.

Accounts holding Class 529 shares are subject to a $10 account setup fee and an annual $10 account maintenance fee. These fees are waived until further notice.

Investors residing in any state may purchase Class 529 shares through an account established with a 529 college savings plan managed by the American Funds organization. Class 529-A, 529-C, 529-T and 529-F-1 shares are structured similarly to the corresponding Class A, C, T and F-1 shares. For example, the same initial sales charges apply to Class 529-A shares as to Class A shares.

Purchase of Class ABLE-A shares Class ABLE-A shares may be purchased only through an account established with a 529A ABLE savings plan managed by the American Funds organization. You may open this type of account and purchase Class ABLE-A shares by contacting any financial advisor (who may impose transaction charges in addition to those described in this prospectus) authorized to sell such an account. You may purchase additional shares in various ways, including through your financial advisor and by mail, telephone, the Internet and bank wire.

Accounts holding Class ABLE-A shares are subject to a $10 account setup fee and an annual $10 account maintenance fee. These fees are waived until further notice.

Investors residing in any state may purchase Class ABLE-A shares through an account established with a 529A ABLE savings plan managed by the American Funds organization. Class ABLE-A shares are structured similarly to the corresponding Class A and Class 529-A shares. For example, the same initial sales charges apply to Class ABLE-A shares as to Class A and Class 529-A shares.

Purchase of Class R shares Class R shares are generally available only to retirement plans established under Internal Revenue Code Sections 401(a), 403(b) or 457, and to nonqualified deferred compensation plans and certain voluntary employee benefit association and post-retirement benefit plans. Class R shares also are generally available only to retirement plans for which plan level or omnibus accounts are held on the books of the fund’s adviser. Class R-5E, R-5 and R-6 shares are generally available only to fee-based programs or through retirement plan intermediaries. In addition, Class R-5 and R-6 shares are available for investment by other registered investment companies approved by the fund’s investment adviser or distributor. Except as otherwise provided in this prospectus, Class R shares are not available to retail nonretirement accounts; traditional and Roth individual retirement accounts (IRAs); Coverdell Education Savings

American Funds U.S. Government Money Market Fund / Prospectus     16

Accounts; SEPs, SARSEPs and SIMPLE IRAs held in brokerage accounts; and 529 college savings plans. Class R-6 shares are available to employer-sponsored SEPs, SARSEPs and Simple IRAs held in fee-based programs that are serviced through retirement plan recordkeepers.

Purchases by employer-sponsored retirement plans Eligible retirement plans generally may open an account and purchase Class A or R shares by contacting any investment dealer (who may impose transaction charges in addition to those described in this prospectus) authorized to sell these classes of the fund’s shares. Some or all R share classes may not be available through certain investment dealers. Additional shares may be purchased through a plan’s administrator or recordkeeper.

Class A shares are generally not available for retirement plans using the PlanPremier ^® or Recordkeeper Direct ^® recordkeeping programs. These programs are proprietary recordkeeping solutions for small retirement plans.

Employer-sponsored retirement plans that are eligible to purchase Class R shares may instead purchase Class A shares and pay the applicable Class A sales charge, provided that their recordkeepers can properly apply a sales charge on plan investments. These plans are not eligible to make initial purchases of $1 million or more in Class A shares of the American Funds and thereby invest in Class A shares without a sales charge, nor are they eligible to establish a statement of intention that qualifies them to purchase Class A shares without a sales charge.

Employer-sponsored retirement plans that invested in Class A shares of any of the American Funds without any sales charge before April 1, 2004, and that continue to meet the eligibility requirements in effect as of that date for purchasing Class A shares at net asset value, may continue to purchase Class A shares of the American Funds without any initial or contingent deferred sales charge.

A 403(b) plan may not invest in Class A shares of any of the American Funds unless it was invested in Class A shares before January 1, 2009.

Purchase minimums and maximums Purchase minimums described in this prospectus may be waived in certain cases. In addition, the fund reserves the right to redeem the shares of any shareholder for their then current net asset value per share if the shareholder’s aggregate investment in the fund falls below the fund’s minimum initial investment amount. See the statement of additional information for details.

For accounts established with an automatic investment plan, the initial purchase minimum of $1,000 may be waived if the purchases (including purchases through exchanges from another fund) made under the plan are sufficient to reach $1,000 within five months of account establishment.

The effective purchase maximums for Class 529-A, 529-C, 529-E, 529-T, 529-F-1 and ABLE-A shares will reflect the maximum applicable contribution limits under state law. See the applicable program description for more information.

17     American Funds U.S. Government Money Market Fund / Prospectus

Exchange Class A, C, T or F-1 shares of any American Fund (other than American Funds U.S. Government Money Market Fund, as described below) may be exchanged for the corresponding 529 share class without a sales charge and Class A shares may be exchanged for Class ABLE-A shares without a sales charge. Rollovers of shares from Class 529-A to Class ABLE-A may also be effected without a sales charge . Exchanges from Class A, C, T or F-1 shares to the corresponding 529 share class (and exchanges from Class A shares to the ABLE-A share class) and rollovers of shares from Class 529-A to Class ABLE-A, particularly in the case of Uniform Gifts to Minors Act or Uniform Transfers to Minors Act custodial accounts, may result in significant legal and tax consequences, as described in the applicable program description. Please consult your financial advisor before making such an exchange.

Exchanges of shares from American Funds U.S. Government Money Market Fund initially purchased without a sales charge to shares of another American Fund will be subject to the appropriate sales charge applicable to the other fund, unless the American Funds U.S. Government Money Market Fund shares were acquired by an exchange from a fund having a sales charge or by reinvestment or cross-reinvestment of dividends or capital gain distributions. For purposes of computing the contingent deferred sales charge on Class C shares, the length of time you have owned your shares will be measured from the first day of the month in which shares were purchased and will not be affected by any permitted exchange.

Exchanges from Class A shares of the fund may generally be made for Class C shares of other American Funds for dollar cost averaging purposes; however, exchanges from Class A shares of the fund to Class C shares of American Funds Inflation Linked Bond Fund, ^® American Funds Short-Term Tax-Exempt Bond Fund, ^® Intermediate Bond Fund of America, ^® Limited Term Tax-Exempt Bond Fund of America ^® and Short-Term Bond Fund of America ^® are not permitted.

Exchanges have the same tax consequences as ordinary sales and purchases. For example, to the extent you exchange shares held in a taxable account that are worth more now than what you paid for them, the gain will be subject to taxation.

See “Transactions by telephone, fax or the Internet” in the section “How to sell shares” of this prospectus for information regarding electronic exchanges.

Please see the statement of additional information for details and limitations on moving investments in certain share classes to different share classes and on moving investments held in certain accounts to different accounts.

How to sell shares

You may sell (redeem) shares in any of the following ways:

Employer-sponsored retirement plans

Shares held in eligible retirement plans may be sold through the plan’s administrator or recordkeeper.

Through your dealer or financial advisor (certain charges may apply)

·  Shares held for you in your dealer’s name must be sold through the dealer.

·  Class F shares must be sold through intermediaries such as dealers or financial advisors.

Writing to American Funds Service Company

American Funds U.S. Government Money Market Fund / Prospectus     18

·  Requests must be signed by the registered shareholder(s).

·  A signature guarantee is required if the redemption is:

—  more than $125,000;

—  made payable to someone other than the registered shareholder(s); or

—  sent to an address other than the address of record or to an address of record that has been changed within the previous 10 days.

·  American Funds Service Company reserves the right to require signature guarantee(s) on any redemption.

·  Additional documentation may be required for redemptions of shares held in corporate, partnership or fiduciary accounts.

Check writing

• Checks must be signed by an authorized and registered shareholder exactly as indicated on your checking account signature card.

• Check writing is only available for Class A shares (and not for Class 529-A and ABLE-A shares).

Telephoning or faxing American Funds Service Company or using the Internet

·  Redemptions by telephone, fax or the Internet (including American FundsLine and americanfunds.com) are limited to $125,000 per American Funds shareholder each day.

·  Checks must be made payable to the registered shareholder.

·  Checks must be mailed to an address of record that has been used with the account for at least 10 days.

The fund typically expects to pay redemption proceeds one business day following receipt and acceptance of a redemption order. However, payment may take longer than one business day and may take up to seven days as generally permitted by the Investment Company Act of 1940, as amended (“1940 Act”). Under the 1940 Act, the fund may be permitted to pay redemption proceeds beyond seven days under certain limited circumstances. In addition, if you recently purchased shares and subsequently request a redemption of those shares, the fund will pay the available redemption proceeds once a sufficient period of time has passed to reasonably ensure that checks or drafts, including certified or cashier’s checks, for the shares purchased have cleared (normally 7 business days from the purchase date).

Under normal conditions, the fund typically expects to meet shareholder redemptions by monitoring the fund’s portfolio and redemption activities and by regularly holding a reserve of highly liquid assets, such as cash or cash equivalents. The fund may use additional methods to meet shareholder redemptions, if they become necessary. These methods may include, but are not limited to, the sale of portfolio assets, the use of overdraft protection afforded by the fund’s custodian bank, borrowing from a line of credit or from other funds advised by the investment adviser or its affiliates, and making payment with fund securities or other fund assets rather than in cash (as further discussed in the following paragraph).

Although payment of redemptions normally will be in cash, the fund’s declaration of trust permits payment of the redemption price wholly or partly with portfolio securities or other fund assets under conditions and circumstances determined by the fund’s board of

19     American Funds U.S. Government Money Market Fund / Prospectus

trustees. On the same redemption date, some shareholders may be paid in whole or in part in securities (which may differ among those shareholders), while other shareholders may be paid entirely in cash. The disposal of the securities received in-kind may be subject to brokerage costs and, until sold, such securities remain at market risk and liquidity risk, including the risk that such securities are or become difficult to sell. If the fund pays your redemption with illiquid or less liquid securities, you will bear the risk of not being able to sell such securities.

Transactions by telephone, fax or the Internet Generally, you are automatically eligible to redeem or exchange shares by telephone, fax or the Internet, unless you notify us in writing that you do not want any or all of these services. You may reinstate these services at any time.

Unless you decide not to have telephone, fax or Internet services on your account(s), you agree to hold the fund, American Funds Service Company, any of its affiliates or mutual funds managed by such affiliates, and each of their respective directors, trustees, officers, employees and agents harmless from any losses, expenses, costs or liabilities (including attorney fees) that may be incurred in connection with the exercise of these privileges, provided that American Funds Service Company employs reasonable procedures to confirm that the instructions received from any person with appropriate account information are genuine. If reasonable procedures are not employed, American Funds Service Company and/or the fund may be liable for losses due to unauthorized or fraudulent instructions.

Frequent trading of fund shares The fund and American Funds Distributors reserve the right to reject any purchase order for any reason. The fund is not designed to serve as a vehicle for frequent trading. Frequent trading of fund shares may lead to increased costs to the fund and less efficient management of the fund’s portfolio, potentially resulting in dilution of the value of the shares held by long-term shareholders. Accordingly, purchases, including those that are part of exchange activity, that the fund or American Funds Distributors has determined could involve actual or potential harm to the fund may be rejected.

The fund, through its transfer agent, American Funds Service Company, maintains surveillance procedures that are designed to detect frequent trading in fund shares. Under these procedures, various analytics are used to evaluate factors that may be indicative of frequent trading. For example, transactions in fund shares that exceed certain monetary thresholds may be scrutinized. American Funds Service Company also may review transactions that occur close in time to other transactions in the same account or in multiple accounts under common ownership or influence. Trading activity that is identified through these procedures or as a result of any other information available to the fund will be evaluated to determine whether such activity might constitute frequent trading. These procedures may be modified from time to time as appropriate to improve the detection of frequent trading, to facilitate monitoring for frequent trading in particular retirement plans or other accounts and to comply with applicable laws.

The American Funds (other than American Funds U.S. Government Money Market Fund) have adopted a “purchase blocking policy” under which any shareholder redeeming shares having a value of $5,000 or more from a fund (other than American Funds U.S. Government Money Market Fund) will be precluded from investing in that fund for 30

American Funds U.S. Government Money Market Fund / Prospectus     20

calendar days after the redemption transaction. This policy also applies to redemptions and purchases that are part of exchange transactions. Under the American Funds’ purchase blocking policy, certain purchases will not be prevented and certain redemptions will not trigger a purchase block, such as:

·  purchases and redemptions of shares having a value of less than $5,000;

·  transactions in Class 529 or Class ABLE-A shares;

·  purchases and redemptions by investment companies managed or sponsored by the fund’s investment adviser or its affiliates, including reallocations and transactions allowing the investment company to meet its redemptions and purchases;

·  retirement plan contributions, loans and distributions (including hardship withdrawals) identified as such on the retirement plan recordkeeper’s system;

·  purchases and redemptions in community foundation accounts;

·  purchase transactions involving in-kind transfers of shares of the fund, rollovers, Roth IRA conversions and IRA recharacterizations, if the entity maintaining the shareholder account is able to identify the transaction as one of these types of transactions; and

·  systematic redemptions and purchases, if the entity maintaining the shareholder account is able to identify the transaction as a systematic redemption or purchase.

Generally, purchases and redemptions will not be considered “systematic” unless the transaction is prescheduled for a specific date.

The fund reserves the right to waive the purchase blocking policy with respect to specific shareholder accounts if American Funds Service Company determines that its surveillance procedures are adequate to detect frequent trading in fund shares in such accounts.

American Funds Service Company will work with certain intermediaries (such as investment dealers holding shareholder accounts in street name, retirement plan recordkeepers, insurance company separate accounts and bank trust companies) to apply their own procedures, provided that American Funds Service Company believes the intermediary’s procedures are reasonably designed to enforce the frequent trading policies of the fund. You should refer to disclosures provided by the intermediaries with which you have an account to determine the specific trading restrictions that apply to you.

If American Funds Service Company identifies any activity that may constitute frequent trading, it reserves the right to contact the intermediary and request that the intermediary either provide information regarding an account owner’s transactions or restrict the account owner’s trading. If American Funds Service Company is not satisfied that the intermediary has taken appropriate action, American Funds Service Company may terminate the intermediary’s ability to transact in fund shares.

There is no guarantee that all instances of frequent trading in fund shares will be prevented.

Notwithstanding the fund’s surveillance procedures and purchase blocking policy described above, all transactions in fund shares remain subject to the right of the fund, American Funds Distributors and American Funds Service Company to restrict potentially abusive trading generally, including the types of transactions described above that will not be prevented or trigger a block under the purchase blocking policy.

21     American Funds U.S. Government Money Market Fund / Prospectus

See the statement of additional information for more information about how American Funds Service Company may address other potentially abusive trading activity in the American Funds.

Dividends and taxes

Dividends The fund declares daily dividends from net investment income and distributes the accrued dividends, which may fluctuate, to you each month. Generally, dividends begin accruing on the day payment for shares is received by the fund or American Funds Service Company.

You may elect to reinvest dividends to purchase additional shares of this fund or other American Funds, or you may elect to receive them in cash. Dividends for the 529 and ABLE-A share classes and retirement plan shareholders will be reinvested automatically.

Taxes on dividends For federal income tax purposes, dividends you receive from the fund will be subject to tax, and also may be subject to state or local taxes — unless you are tax-exempt or your account is tax-favored.

Taxes on transactions Generally, redemptions of shares of the fund, including exchanges, will not result in a capital gain or loss for federal or state income tax purposes.

Exchanges within a tax-deferred retirement plan account will not result in a capital gain or loss for federal or state income tax purposes. With limited exceptions, distributions from a retirement plan account are taxable as ordinary income.

Shareholder fees Fees borne directly by the fund normally have the effect of reducing a shareholder’s taxable income on distributions. By contrast, fees paid directly to advisors by a fund shareholder for ongoing advice are deductible for income tax purposes only to the extent that they (combined with certain other qualifying expenses) exceed 2% of such shareholder’s adjusted gross income.

Please see your tax advisor for more information. Holders of Class 529 and Class ABLE-A shares should refer to the applicable program description for more information regarding the tax consequences of selling Class 529 or Class ABLE-A shares, as applicable.

Choosing a share class The fund offers different classes of shares through this prospectus. The services or share classes available to you may vary depending upon how you wish to purchase shares of the fund.

Each share class of a fund represents an investment in the same portfolio of securities, but each class has its own sales charge and expense structure, allowing you to choose the class that best fits your situation. For example, while Class F-1 shares are subject to 12b-1 fees and subtransfer agency fees payable to third-party service providers, Class F-2 shares are subject only to subtransfer agency fees payable to third-party service providers (and not 12b-1 fees) and Class F-3 shares are not subject to any such additional fees. The different fee structures allow the investor to choose how to pay for advisory platform expenses. Class R shares offer different levels of 12b-1 and recordkeeping fees so that a plan can choose the class that best meets the cost associated with obtaining investment related services and participant level recordkeeping for the plan. When you purchase shares of the fund for an individual-type account, you should choose a share class. If none is chosen, your investment will

American Funds U.S. Government Money Market Fund / Prospectus     22

be made in Class A shares or, in the case of a 529 plan investment, Class 529-A shares (or, if you are investing through a financial intermediary who offers only Class T and 529-T shares, your investment will be made in Class T or Class 529-T shares, as applicable).

Factors you should consider when choosing a class of shares include:

·  Whether you want or need the flexibility to effect exchanges among the American Funds without the imposition of a sales charge (for example, while Class A shares offer such exchange privileges, Class T shares do not);

·  whether you plan to take any distributions in the near future (for example, the contingent deferred sales charge will not be waived if you sell your Class 529-C shares to cover higher education expenses); and

·  availability of share classes:

—  Class C and 529-C shares may be acquired only by exchanging from Class C or 529-C shares of other American Funds;

—  Class F and 529-F-1 shares are available (i) to fee-based programs of investment dealers that have special agreements with the fund’s distributor, (ii) to financial intermediaries that have been approved by, and that have special agreements with, the fund’s distributor to offer Class F and 529-F-1 shares to self-directed investment brokerage accounts that may charge a transaction fee, (iii) to certain registered investment advisors and (iv) to other intermediaries approved by the fund’s distributor;

—  Class F-3 shares are also available to institutional investors, which include, but are not limited to, charitable organizations, governmental institutions and corporations. For accounts held and serviced by the fund’s transfer agent the minimum investment amount is $1,000,000; and

—  Class R shares are available (i) to retirement plans established under Internal Revenue Code Sections 401(a) (including 401(k) plans), 403(b) or 457, (ii) to nonqualified deferred compensation plans and certain voluntary employee benefit association and post-retirement benefit plans, (iii) to certain institutional investors (including, but not limited to, certain charitable organizations), (iv) to certain registered investment companies approved by the fund’s investment adviser or distributor and (v) to other institutional-type accounts.

Each investor’s financial considerations are different. You should speak with your financial advisor to help you decide which share class is best for you.

Sales charges

Class A shares Class A shares of the fund are sold without an initial sales charge. However, if shares of the fund are exchanged for shares of an American Funds non–money market fund, the sales charge applicable to the non–money market fund may apply.

Class C shares Class C shares are sold without any initial sales charge. A contingent deferred sales charge of 1% applies if Class C shares are sold within one year of purchase. The contingent deferred sales charge is eliminated one year after purchase.

23     American Funds U.S. Government Money Market Fund / Prospectus

Any contingent deferred sales charge paid by you on sales of Class C shares, expressed as a percentage of the applicable redemption amount, may be higher or lower than the percentages described above due to rounding.

Class T shares Class T shares of the fund are sold without an initial sales charge. However, if shares of the fund are exchanged for shares of an American Funds non-money market fund, the sales charge applicable to the non–money market fund may apply.

Class 529-E and Class F shares Class 529-E and Class F shares (including Class 529-F-1 shares) are sold without any initial or contingent deferred sales charge.

Class R shares Class R shares are sold without any initial or contingent deferred sales charge. The distributor will pay dealers annually asset-based compensation of up to 1.00% for sales of Class R-1 shares, up to .75% for Class R-2 shares, up to .60% for Class R-2E shares, up to .50% for Class R-3 shares and up to .25% for Class R-4 shares. No dealer compensation is paid on sales of Class R-5E, R-5 or R-6 shares. The fund may reimburse the distributor for these payments through its plans of distribution.

See “Plans of distribution” in this prospectus for ongoing compensation paid to your dealer or financial advisor for all share classes.

Contingent deferred sales charges Shares acquired through reinvestment of dividends are not subject to a contingent deferred sales charge. In addition, the contingent deferred sales charge may be waived in certain circumstances. See “Contingent deferred sales charge waivers” in the “Sales charge waivers” section of this prospectus. For purposes of determining the contingent deferred sales charge, if you sell only some of your shares, shares that are not subject to any contingent deferred sales charge will be sold first, followed by shares that you have owned the longest.

Sales charge waivers Certain financial intermediaries that distribute shares of the American Funds may impose different sales charge waivers than those described in this prospectus. Such variations in sales charge waivers are described in an appendix to this prospectus titled “Sales charge waivers.” Note that such sales charge waivers and discounts offered through a particular intermediary, as set forth in the appendix to this prospectus, are implemented and administered solely by that intermediary. Please contact the applicable intermediary to ensure that you understand the steps you must take in order to qualify for any available waivers or discounts.

Right of reinvestment If you notify American Funds Service Company prior to the time of reinvestment, you may reinvest proceeds from a redemption, dividend payment or capital gain distribution without a sales charge in the same fund or other American Funds, provided that the reinvestment occurs within 90 days after the date of the redemption, dividend payment or distribution and is made into the same account from which you redeemed the shares or received the dividend payment or distribution. If the account has been closed, you may reinvest without a sales charge if the new receiving account has the same registration as the closed account and the reinvestment is made within 90 days after the date of redemption, dividend payment or distribution.

Proceeds from a redemption and all dividend payments and capital gain distributions will be reinvested in the same share class from which the original redemption, dividend payment or distribution was made. Any contingent deferred sales charge on Class C shares will be credited to your account. Redemption proceeds of Class A shares

American Funds U.S. Government Money Market Fund / Prospectus     24

representing direct purchases in American Funds U.S. Government Money Market Fund that are reinvested in other American Funds will be subject to a sales charge.

Proceeds will be reinvested at the next calculated net asset value after your request is received by American Funds Service Company, provided that your request contains all information and legal documentation necessary to process the transaction. For purposes of this “right of reinvestment policy,” automatic transactions (including, for example, automatic purchases, withdrawals and payroll deductions) and ongoing retirement plan contributions are not eligible for investment without a sales charge. You may not reinvest proceeds in the American Funds as described in this paragraph if such proceeds are subject to a purchase block as described under “Frequent trading of fund shares” in this prospectus. This paragraph does not apply to certain rollover investments as described under “Rollovers from retirement plans to IRAs” in this prospectus. Depending on the financial intermediary holding your account, your reinvestment privileges may be unavailable or differ from those described in this prospectus.

Contingent deferred sales charge waivers The contingent deferred sales charge on Class C shares will be waived in the following cases:

·  permitted exchanges of shares, except if shares acquired by exchange are then redeemed within the period during which a contingent deferred sales charge would apply to the initial shares purchased;

·  tax-free returns of excess contributions to IRAs;

·  redemptions due to death or postpurchase disability of the shareholder (this generally excludes accounts registered in the names of trusts and other entities);

·  in the case of joint tenant accounts, if one joint tenant dies, a surviving joint tenant, at the time he or she notifies American Funds Service Company of the other joint tenant’s death and removes the decedent’s name from the account, may redeem shares from the account without incurring a contingent deferred sales charge; however, redemptions made after American Funds Service Company is notified of the death of a joint tenant will be subject to a contingent deferred sales charge;

·  for 529 share classes only, redemptions due to a beneficiary’s death, postpurchase disability or receipt of a scholarship (to the extent of the scholarship award);

·  redemptions due to the complete termination of a trust upon the death of the trustor/grantor or beneficiary, but only if such termination is specifically provided for in the trust document; and

·  the following types of transactions, if they do not exceed 12% of the value of an account annually:

—  required minimum distributions taken from retirement accounts upon the shareholder’s attainment of age 70½ (required minimum distributions that continue to be taken by the beneficiary(ies) after the account owner is deceased also qualify for a waiver); and

—  redemptions through an automatic withdrawal plan (“AWP”) (see “Automatic withdrawals” under “Shareholder account services and privileges” in the statement of additional information). For each AWP payment, assets that are not subject to a contingent deferred sales charge, such as shares acquired through reinvestment of dividends and/or capital gain distributions, will be redeemed first and will count toward the 12% limit. If there is an insufficient amount of assets not subject to a contingent deferred sales charge to cover a particular AWP payment,

25     American Funds U.S. Government Money Market Fund / Prospectus

shares subject to the lowest contingent deferred sales charge will be redeemed next until the 12% limit is reached. Any dividends and/or capital gain distributions taken in cash by a shareholder who receives payments through an AWP will also count toward the 12% limit. In the case of an AWP, the 12% limit is calculated at the time an automatic redemption is first made, and is recalculated at the time each additional automatic redemption is made. Shareholders who establish an AWP should be aware that the amount of a payment not subject to a contingent deferred sales charge may vary over time depending on fluctuations in the value of their accounts. This privilege may be revised or terminated at any time.

For purposes of this paragraph, “account” means your investment in the applicable class of shares of the particular fund from which you are making the redemption.

Contingent deferred sales charge waivers are allowed only in the cases listed here and in the statement of additional information. For example, contingent deferred sales charge waivers will not be allowed on redemptions of Class 529-C shares due to termination of CollegeAmerica; a determination by the Internal Revenue Service that CollegeAmerica does not qualify as a qualified tuition program under the Code; proposal or enactment of law that eliminates or limits the tax-favored status of CollegeAmerica; or elimination of the fund by Virginia529 as an option for additional investment within CollegeAmerica.

To have your Class C contingent deferred sales charge waived, you must inform your advisor or American Funds Service Company at the time you redeem shares that you qualify for such a waiver.

In addition to the information in this prospectus, you may obtain more information about share classes, sales charges and sales charge reductions and waivers through a link on the home page of the American Funds website at americanfunds.com, from the statement of additional information or from your financial advisor.

American Funds U.S. Government Money Market Fund / Prospectus     26

Rollovers from retirement plans to IRAs Assets from retirement plans may be invested in Class A, C or F shares through an IRA rollover, subject to the other provisions of this prospectus. Class C shares are not available if the assets are being rolled over from investments held in the American Funds Recordkeeper Direct and PlanPremier retirement plan recordkeeping programs.

Rollovers to IRAs from retirement plans that are rolled into Class A shares will be subject to applicable sales charges. The following rollovers to Class A shares will be made without a sales charge:

·  rollovers to Capital Bank and Trust Company ^SM IRAs if the assets were invested in American Funds at the time of distribution;

·  rollovers to IRAs from 403(b) plans with Capital Bank and Trust Company as custodian; and

·  rollovers to Capital Bank and Trust Company IRAs from investments held in the American Funds Recordkeeper Direct and PlanPremier retirement plan recordkeeping programs.

IRA rollover assets that roll over without a sales charge as described above will not be subject to a contingent deferred sales charge, and investment dealers will be compensated solely with an annual service fee that begins to accrue immediately. All other rollovers invested in Class A shares, as well as future contributions to the IRA, will be subject to sales charges and to the terms and conditions generally applicable to Class A share investments as described in this prospectus and in the statement of additional information.

Other sales charge waivers Waivers of all or a portion of the contingent deferred sales charge on Class C shares will be granted for transactions requested by financial intermediaries as a result of (i) pending or anticipated regulatory matters that require investor accounts to be moved to a different share class or (ii) conversions of IRAs from brokerage to advisory accounts in cases where new investments in brokerage IRA accounts have been restricted by the intermediary.

27     American Funds U.S. Government Money Market Fund / Prospectus

Plans of distribution The fund has plans of distribution, or “12b-1 plans,” for certain share classes under which it may finance activities intended primarily to sell shares, provided that the categories of expenses are approved in advance by the fund’s board of trustees. The plans provide for payments, based on annualized percentages of average daily net assets, of:

A portion (up to .15% for Class A, 529-A and ABLE-A shares and .25% for Class C, 529-C, 529-E, T, 529-T, F-1, 529-F-1 and R shares) may be used to pay service fees to qualified dealers for providing certain shareholder services. The amount remaining for each share class, if any, may be used for distribution expenses.

The 12b-1 fees paid by each applicable share class of the fund, as a percentage of average net assets for the most recent fiscal year, are indicated in the Annual Fund Operating Expenses table on page 1 of this prospectus. Since these fees are paid out of the fund’s assets on an ongoing basis, over time they may cost you more than paying other types of sales charges or service fees and reduce the return on your investment.

The fund may suspend 12b-1 payments under agreements between its principal underwriter and intermediaries and other entities that sell fund shares. The fund is currently suspending certain 12b-1 payments in this low interest rate environment.

Other compensation to dealers American Funds Distributors, at its expense, provides additional compensation to investment dealers. These payments may be made, at the discretion of American Funds Distributors, to the top 100 dealers (or their affiliates) that have sold shares of the American Funds. A number of factors will be considered in determining payments, including the qualifying dealer’s sales, assets and positive cash flows, and the quality of the dealer’s relationship with American Funds Distributors. The payment will be determined using a formula applied consistently to dealers based on the relevant facts and circumstances. The level of payments made to a qualifying firm in any given year will vary and (excluding payments for meetings as described below) will represent the sum of (a) up to .10% of the previous year’s American Funds sales by that dealer and (b) up to .02% of American Funds assets attributable to that dealer, with an adjustment made for the dealer’s positive cash flows and the quality of the dealer’s relationship with American Funds Distributors. Class R shares and other retirement plan assets are generally excluded from the formula. Certain investment dealers may direct American Funds Distributors to exclude additional assets. For calendar year 2017, aggregate payments made by American Funds Distributors to dealers were less than .02% of the average assets of the American Funds. Aggregate payments made by American Funds Distributors to dealers may also change from year to year. American Funds Distributors makes these payments to help defray the costs incurred by qualifying dealers in connection with efforts to educate financial advisors about the American Funds so that they can make recommendations and provide services that are suitable and meet shareholder needs. These payments may also be made to help defray the costs associated with the dealer firms’ provision of account related services and activities.

American Funds U.S. Government Money Market Fund / Prospectus     28

American Funds Distributors will, on an annual basis, determine the advisability of continuing these payments.

Firms receiving additional compensation payments must sign a letter acknowledging the purpose of the payment and American Funds Distributors’ goal that the payment will help facilitate education of the firm’s financial advisors about the American Funds to help the advisors make suitable recommendations and better serve their clients who invest in the funds. The letters generally require the firms to (1) have significant assets invested in the American Funds, (2) perform the due diligence necessary to classify the American Funds as “approved” or “preferred” (or an equivalent) on their platform, (3) not provide financial advisors, branch managers or associated persons with any financial incentives to promote the sales of one approved fund group over another approved group, (4) provide opportunities for their clients to obtain individualized advice, (5) provide American Funds Distributors broad access to their financial advisors and product platforms and develop a business plan to achieve such access, and (6) work with the fund’s transfer agent to promote operational efficiencies and to facilitate necessary communication between the American Funds and the firm’s clients who own shares of the American Funds.

American Funds Distributors may also pay expenses associated with meetings and other training and educational opportunities conducted by selling dealers, advisory platform providers and other intermediaries to facilitate educating financial advisors and shareholders about the American Funds. For example, some of these expenses may include, but not be limited to, meeting sponsor fees, meeting location fees, and fees to obtain lists of financial advisors to better tailor training and education opportunities.

If investment advisers, distributors or other affiliates of mutual funds pay additional compensation or other incentives to investment dealers in differing amounts, dealer firms and their advisors may have financial incentives for recommending a particular mutual fund over other mutual funds or investments. You should consult with your financial advisor and review carefully any disclosure by your financial advisor’s firm as to compensation received.

29     American Funds U.S. Government Money Market Fund / Prospectus

Fund expenses Note that, unless otherwise stated, references to Class A, C, T and F-1 shares in this “Fund expenses” section do not include the corresponding Class 529 or ABLE shares.

In periods of market volatility, assets of the fund may decline significantly, causing total annual fund operating expenses (as a percentage of the value of your investment) to become higher than the numbers shown in the Annual Fund Operating Expenses table on page 1 of this prospectus.

For all share classes, “Other expenses” items in the Annual Fund Operating Expenses table in this prospectus include fees for administrative services provided by the fund’s investment adviser and its affiliates. Administrative services include, but are not limited to, coordinating, monitoring, assisting and overseeing third parties that provide services to fund shareholders. The fund’s investment adviser receives an administrative services fee at the annual rate of .01% of the average daily net assets of the fund attributable to Class A shares and .05% of the average daily net assets of the fund attributable to Class C, T, F, R, 529 and ABLE-A shares for its provision of administrative services.

The “Other expenses” items in the Annual Fund Operating Expenses table also include custodial, legal and transfer agent (and, if applicable, subtransfer agent/recordkeeping) payments and various other expenses applicable to all share classes.

Subtransfer agency and recordkeeping fees Subtransfer agent/recordkeeping payments may be made to third parties (including affiliates of the fund’s investment adviser) that provide subtransfer agent, recordkeeping and/or shareholder services with respect to certain shareholder accounts in lieu of the transfer agent providing such services. The amount paid for subtransfer agent/recordkeeping services varies depending on the share class and services provided, and typically ranges from $3 to $18 per account. Although Class F-3 shares are not subject to any subtransfer agency or recordkeeping fees, Class F-1 and F-2 shares are subject to subtransfer agency fees of up to .12% of fund assets. For Class 529 and ABLE-A shares, an expense of up to a maximum of .10% paid to a state or states for oversight and administrative services is included as an “Other expenses” item.

For employer-sponsored retirement plans, the amount paid for subtransfer agent/ recordkeeping services varies depending on the share class selected. The table below shows the maximum payments to entities providing these services to retirement plans.

^* Payment amount depends on the date services commenced.

American Funds U.S. Government Money Market Fund / Prospectus     30

Financial highlights The Financial Highlights table is intended to help you understand the fund’s results for the past five fiscal years (and for the six months ended March 31, 2018). On April 1, 2016, the fund was redesignated from a prime money market fund to a government money market fund. Information presented below prior to that date reflects fund operations as a prime money market fund. Certain information reflects financial results for a single share of a particular class. The total returns in the table represent the rate that an investor would have earned or lost on an investment in the fund (assuming reinvestment of all dividends). Where indicated, figures in the table reflect the impact, if any, of certain reimbursements from Capital Research and Management Company. For more information about these reimbursements, see the fund’s statement of additional information and annual report. The information in the Financial Highlights table (other than information for the six months ended March 31, 2018) has been audited by PricewaterhouseCoopers LLP, whose current report, along with the fund’s financial statements, is included in the statement of additional information, which is available upon request. The information for the six-month period presented has been derived from the fund's unaudited financial statements and includes all adjustments that management considers necessary for a fair presentation of such information for the period presented.

¹  Based on average shares outstanding.

2  This column reflects the impact, if any, of certain reimbursements from Capital Research and Management Company. During some of the periods shown, Capital Research and Management Company reimbursed a portion of miscellaneous fees and expenses for certain share classes due to lower short-term interest rates.

³  Total returns exclude any applicable sales charges, including contingent deferred sales charges.

⁴  Based on operations for a period that is less than a full year.

⁵  Unaudited.

⁶  Amount less than $.01.

⁷  Not annualized.

⁸  Annualized.

⁹  Amount less than .01%.

¹⁰  Amount less than $1 million.

¹¹  All or a significant portion of assets in this class consisted of seed capital invested by Capital Research and Management Company and/or its affiliates. Fees for distribution services are not charged or accrued on these seed capital assets. If such fees were paid by the fund on seed capital assets, fund expenses would have been higher and net income and total return would have been lower.

¹²  Class T and 529-T shares began investment operations on April 7, 2017.

¹³  Class F-3 shares began investment operations on January 27, 2017.

¹⁴  Class R-2E shares began investment operations on August 29, 2014.

¹⁵  Class R-5E shares began investment operations on November 20, 2015.