Federal Income Tax Consequences

The following is a brief summary of the material federal income tax aspects of the 401(k) Plan. You should not rely on this summary as a complete or definitive description of the material federal income tax consequences relating to the 401(k) Plan. Statutory provisions change, as do their interpretations, and their application may vary in individual circumstances. Finally, the consequences under applicable state and local income tax laws may not be the same as under the federal income tax laws. Consult your tax advisor with respect to any distribution from the 401(k) Plan and transactions involving the 401(k) Plan.

As a “tax-qualified retirement plan,” the Code affords the 401(k) Plan special tax treatment, including:

First Seacoast Bank will administer the 401(k) Plan to comply with the requirements of the Code as of the applicable effective date of any change in the law.

Lump-Sum Distribution. A distribution from the 401(k) Plan to a participant or the beneficiary of a participant will qualify as a lump-sum distribution if it is made within one taxable year, on account of the participant’s death, disability or separation from service, or after the participant attains age 59¹⁄₂, and consists of the balance credited to participants under the 401(k) Plan and all other profit sharing plans, if any, maintained by First Seacoast Bank. The portion of any lump-sum distribution required to be included in your taxable income for federal income tax purposes consists of the entire amount of the lump-sum distribution, less the amount of after-tax contributions, if any, you have made to this 401(k) Plan and any other profit sharing plans maintained by First Seacoast Bank, which is included in the distribution.

First Seacoast Bancorp, Inc. Common Stock Included in Lump-Sum Distribution. If a lump-sum distribution includes First Seacoast Bancorp, Inc. common stock, the distribution generally will be taxed in the manner described above, except that the total taxable amount may be reduced by the amount of any net unrealized appreciation with respect to First Seacoast Bancorp, Inc. common stock; that is, the excess of the value of First Seacoast Bancorp, Inc.at the time of the distribution over its cost or other basis of the securities to the trust. The tax basis of First Seacoast Bancorp, Inc. common stock, for purposes of computing gain or loss on its subsequent sale, equals the value of First Seacoast Bancorp, Inc. common stock at the time of distribution, less the amount of net unrealized appreciation. Any gain on a subsequent sale or other taxable disposition of First Seacoast Bancorp, Inc. common stock, to the extent of the amount of net unrealized appreciation at the time of distribution, will constitute long-term capital gain, regardless of the holding period of First Seacoast Bancorp, Inc. common stock. Any gain on a subsequent sale or other taxable disposition of First Seacoast Bancorp, Inc. common stock, in excess of the amount of net unrealized appreciation at the time of distribution, will be considered long-term capital gain. The recipient of a distribution may elect to include the amount of any net unrealized appreciation in the total taxable amount of the distribution, to the extent allowed by regulations to be issued by the Internal Revenue Service.

16

Distributions: Rollovers and Direct Transfers to Another Qualified Plan or to an IRA. You may roll over virtually all distributions from the 401(k) Plan to another qualified plan or to an individual retirement account in accordance with the terms of the other plan or account.

Notice of Your Rights Concerning Employer Securities

Federal law provides specific rights concerning investments in employer securities. Because you may in the future have investments in First Seacoast Bancorp, Inc. common stock under the 401(k) Plan, you should take the time to read the following information carefully.

Your Rights Concerning Employer Securities. The 401(k) Plan must allow you to elect to move any portion of your account that is invested in First Seacoast Bancorp, Inc. common stock from that investment into other investment alternatives under the 401(k) Plan. You may contact the 401(k) Plan administrator shown above for specific information regarding this right, including how to make this election. In deciding whether to exercise this right, you will want to give careful consideration to the information below that describes the importance of diversification. All of the investment options under the 401(k) Plan are available to you if you decide to diversify out of your investment in First Seacoast Bancorp, Inc. common stock.

The Importance of Diversifying Your Retirement Savings. To help achieve long-term retirement security, you should give careful consideration to the benefits of a well-balanced and diversified investment portfolio. Spreading your assets among different types of investments can help you achieve a favorable rate of return, while minimizing your overall risk of losing money. This is because market or other economic conditions that cause one category of assets, or one particular security, to perform very well often cause another asset category, or another particular security, to perform poorly. If you invest more than 20% of your retirement savings in any one company or industry, your savings may not be properly diversified. Although diversification is not a guarantee against loss, it is an effective strategy to help you manage investment risk.

In deciding how to invest your retirement savings, you should take into account all of your assets, including any retirement savings outside of the 401(k) Plan. No single approach is right for everyone because, among other factors, individuals have different financial goals, different time horizons for meeting their goals, and different tolerance for risk. Therefore, you should carefully consider the rights described here and how these rights affect the amount of money that you invest in First Seacoast Bancorp, Inc. common stock through the 401(k) Plan.

It is also important to periodically review your investment portfolio, your investment objectives, and the investment options under the 401(k) Plan to help ensure that your retirement savings will meet your retirement goals.

Additional Employee Retirement Income Security Act, as amended, Considerations

As noted above, the 401(k) Plan is subject to certain provisions of ERISA, including special provisions relating to control over the 401(k) Plan’s assets by participants and beneficiaries. The 401(k) Plan’s feature that allows you to direct the investment of your account balances is intended to satisfy the requirements of Section 404(c) of ERISA relating to control over plan assets by a participant or beneficiary. The effect of this is two-fold. First, you will not be deemed a “fiduciary” because of your exercise of investment discretion. Second, no person who otherwise is a fiduciary, such as First Seacoast Bank, the 401(k) Plan administrator, or the 401(k) Plan’s trustee is liable under the fiduciary

17

responsibility provision of ERISA for any loss which results from your exercise of control over the assets in your 401(k) Plan account.

Because you will be entitled to invest all or a portion of your account balance in the 401(k) Plan in First Seacoast Bancorp, Inc. common stock, the regulations under Section 404(c) of the ERISA require that the 401(k) Plan establish procedures that ensure the confidentiality of your decision to purchase, hold, or sell employer securities, except to the extent that disclosure of such information is necessary to comply with federal or state laws not preempted by ERISA. These regulations also require that your exercise of voting and similar rights with respect to First Seacoast Bancorp, Inc. common stock be conducted in a way that ensures the confidentiality of your exercise of these rights.

Securities and Exchange Commission Reporting and Short-Swing Profit Liability

Section 16 of the Securities Exchange Act of 1934 imposes reporting and liability requirements on officers, directors, and persons beneficially owning more than 10% of public companies, such as First Seacoast Bancorp, Inc. Section 16(a) of the Securities Exchange Act of 1934 requires the filing of reports of beneficial ownership. Within 10 days of becoming an officer, director or person beneficially owning more than 10% of the shares of First Seacoast Bancorp, Inc., a Form 3 reporting initial beneficial ownership must be filed with the Securities and Exchange Commission. Changes in beneficial ownership, such as purchases, sales and gifts generally must be reported periodically, either on a Form 4 within two business days after the change occurs, or annually on a Form 5 within 45 days after the close of fiscal year of First Seacoast Bancorp, Inc. Discretionary transactions in and beneficial ownership of First Seacoast Bancorp, Inc. common stock by officers, directors and persons beneficially owning more than 10% of First Seacoast Bancorp, Inc. common stock generally must be reported to the Securities and Exchange Commission by such individuals.

In addition to the reporting requirements described above, Section 16(b) of the Securities Exchange Act of 1934 provides for the recovery by First Seacoast Bancorp, Inc. of profits realized by an officer, director or any person beneficially owning more than 10% of First Seacoast Bancorp, Inc. common stock resulting from non-exempt purchases and sales of First Seacoast Bancorp, Inc. common stock within any six (6)-month period.

The Securities and Exchange Commission has adopted rules that provide exemptions from the profit recovery provisions of Section 16(b) for all transactions in employer securities within an employee benefit plan, provided certain requirements are met. These requirements generally involve restrictions upon the timing of elections to acquire or dispose of employer securities for the accounts of Section 16(b) persons.

Except for distributions of First Seacoast Bancorp, Inc. common stock due to death, disability, retirement, termination of employment or under a qualified domestic relations order, persons affected by Section 16(b) are required to hold shares of First Seacoast Bancorp, Inc. common stock distributed from the 401(k) Plan for six (6) months following such distribution and are prohibited from directing additional purchases of First Seacoast Bancorp, Inc. common stock for six (6) months after receiving such a distribution.

Financial Information Regarding Plan Assets

Financial information representing the net assets available for 401(k) Plan benefits and the change in net assets available for 401(k) Plan benefits is available upon written request to the 401(k) Plan administrator at the address shown above.

18

LEGAL OPINION

The validity of the issuance of First Seacoast Bancorp, Inc. common stock has been passed upon by Luse Gorman, PC, Washington, D.C., which the firm has acted as special counsel to First Seacoast Bancorp, Inc. in connection with the stock offering of First Seacoast Bancorp, Inc.

19

PROSPECTUS

FIRST SEACOAST BANCORP, INC.

(Proposed Holding Company for First Seacoast Bank)

Up to 3,795,000 Shares of Common Stock

First Seacoast Bancorp, Inc. is offering shares of common stock for sale, on a best efforts basis, in connection with the conversion of First Seacoast Bancorp, MHC from the mutual holding company to the stock holding company form of organization. The shares being offered for sale represent the ownership interest of First Seacoast Bancorp, MHC in First Seacoast Bancorp. First Seacoast Bancorp’s common stock is listed on the Nasdaq Capital Market under the symbol “FSEA.” We expect to list First Seacoast Bancorp, Inc.’s common stock on the Nasdaq Capital Market under the symbol “FSEA.” We are an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012.

The shares of common stock are first being offered for sale in a subscription offering to eligible depositors and borrowers of First Seacoast Bank as of specified eligibility dates and to tax-qualified employee benefit plans of First Seacoast Bank. Shares not purchased in the subscription offering may be offered for sale to the general public in a community offering, with a preference given first to residents of the communities served by First Seacoast Bank and then to stockholders of First Seacoast Bancorp. Any shares of common stock not purchased in the subscription offering or in any community offering may be offered for sale to the public through a syndicate of broker-dealers, referred to in this prospectus as the syndicated community offering. The syndicated community offering may begin before the subscription offering and any community offering (including any extensions) have expired. However, no shares purchased in the subscription offering or in any community offering will be issued until the completion of any syndicated community offering. We must sell a minimum of 2,805,000 shares to complete the conversion and stock offering.

In addition to the shares being offered for sale in the stock offering, the shares of common stock of First Seacoast Bancorp currently owned by the public will be exchanged for shares of common stock of First Seacoast Bancorp, Inc. based on an exchange ratio that will result in existing public stockholders of First Seacoast Bancorp owning approximately the same percentage of common stock of First Seacoast Bancorp, Inc. as they owned in the common stock of First Seacoast Bancorp immediately before the completion of the conversion and stock offering. We expect to issue up to 3,074,548 shares in the exchange.

The minimum purchase order is 25 shares. Generally, no individual, or individuals acting through a single qualifying account held jointly, may purchase more than 40,000 shares ($400,000) of common stock, and no person or entity, together with associates or persons acting in concert with such person or entity, may purchase more than 40,000 shares ($400,000) of common stock in all categories of the stock offering combined.

The subscription offering will expire at 2:00 p.m., Eastern time, on December ___, 2022. We expect that the community offering, if held, will expire at the same time. We may extend the expiration date of the subscription and/or community offerings without notice to you until January ___, 2023, or longer if the Federal Reserve Board approves a later date. No single extension may exceed 90 days and the stock offering must be completed by ________, 2023. Once submitted, orders are irrevocable unless the subscription and community offerings are terminated or extended, with regulatory approval, beyond ________, 2023, or the number of shares of common stock to be sold is increased to more than 3,795,000 shares or decreased to less than 2,805,000 shares. If the subscription and community offerings are extended past ________, 2023, all subscribers will be notified and given the opportunity to confirm, change or cancel their orders. If you do not respond to the notice of extension, we will promptly return your funds with interest or cancel your deposit account withdrawal authorization. If the number of shares to be sold in the stock offering is increased to more than 3,795,000 shares or decreased to less than 2,805,000 shares, we will resolicit subscribers, and all funds delivered to us to purchase shares of common stock in the subscription offering and in any community offering will be returned promptly with interest. Funds received in the subscription offering and in any community offering will be held in a segregated account at First Seacoast Bank and will earn interest at ___% per annum until completion or termination of the stock offering.

Keefe, Bruyette & Woods, Inc. is assisting us in selling the shares of common stock, on a best efforts basis, in the subscription offering and in any community offering, and will serve as sole manager for any syndicated community offering. Keefe, Bruyette & Woods, Inc. is not required to purchase any shares of common stock that are being offered for sale in the stock offering.

TABLE OF CONTENTS

i

SUMMARY

The following summary explains the significant aspects of the conversion and the stock offering, as well as the exchange of existing shares of First Seacoast Bancorp common stock for shares of First Seacoast Bancorp, Inc. common stock. It may not contain all of the information that is important to you. Before making an investment decision, you should read this entire document carefully, including the consolidated financial statements and related notes and the section entitled “Risk Factors.”

Our Organizational Structure and the Proposed Conversion and Stock Offering

Since July 16, 2019, when First Seacoast Bank reorganized into the mutual holding company structure, we have operated in a two-tier mutual holding company structure. First Seacoast Bancorp, a federally-chartered corporation, is the publicly-traded stock holding company and the parent company of First Seacoast Bank. At June 30, 2022, First Seacoast Bancorp had consolidated assets of $510.2 million, total deposits of $387.9 million and stockholders’ equity of $51.9 million. First Seacoast Bancorp’s parent company is First Seacoast Bancorp, MHC, a federally-chartered mutual holding company. At June 30, 2022, First Seacoast Bancorp had 6,064,891 shares of common stock outstanding, of which 3,345,925 shares, or 55.2%, were owned by First Seacoast Bancorp, MHC, and the remaining 2,718,966 shares were owned by the public.

Pursuant to the terms of the plan of conversion and reorganization, which we refer to as the plan of conversion throughout this prospectus, we are converting from the mutual holding company corporate structure to the fully public stock holding company corporate structure. Upon completion of the conversion and stock offering, First Seacoast Bancorp, MHC and First Seacoast Bancorp will cease to exist and First Seacoast Bancorp, Inc., a Maryland corporation, will become the successor holding company to First Seacoast Bancorp and will become the stock holding company of First Seacoast Bank. The conversion will be accomplished by the merger of First Seacoast Bancorp, MHC with and into First Seacoast Bancorp, followed by the merger of First Seacoast Bancorp with and into First Seacoast Bancorp, Inc. The shares of First Seacoast Bancorp, Inc. common stock being offered for sale represent the majority ownership interest in First Seacoast Bancorp currently owned by First Seacoast Bancorp, MHC. Public stockholders of First Seacoast Bancorp will receive shares of common stock of First Seacoast Bancorp, Inc. in exchange for their shares of First Seacoast Bancorp at an exchange ratio intended to preserve the same aggregate ownership interest in First Seacoast Bancorp, Inc. as they had in First Seacoast Bancorp, adjusted downward to reflect certain assets held by First Seacoast Bancorp, MHC, without giving effect to new shares purchased in the stock offering or cash paid in lieu of any fractional shares. The shares of First Seacoast Bancorp common stock owned by First Seacoast Bancorp, MHC will be canceled.

The following diagram shows our current organizational structure, reflecting ownership percentages at June 30, 2022:

1

After the conversion and stock offering are completed, we will be organized as a fully public stock holding company, as follows:

Our Business

Our core business activities are conducted primarily through First Seacoast Bank. Founded in 1890, First Seacoast Bank has headquarters in Dover, New Hampshire, and four additional branch offices in the Seacoast region. First Seacoast Bank is engaged principally in the business of attracting deposits from the general public and investing those deposits, together with funds generated from operations and borrowings from the Federal Home Loan Bank, in one- to four-family residential real estate loans, commercial real estate and multi-family real estate loans, acquisition, development and land loans, commercial and industrial loans, home equity loans and lines of credit and consumer loans. In recent years, we have increased our focus, consistent with what we believe to be conservative underwriting standards, on originating higher yielding commercial real estate and commercial and industrial loans.

Our results of operations are largely dependent on net interest income, which is the difference between the interest earned on loans and securities and interest paid on deposits and borrowings, and non-interest income largely from customer service fees. The results of operations are also affected by the level of operating expenses, the provision for loan losses, the impact of federal and state income taxes, the relative levels of interest rates and local and national economic activity.

Investment management services are offered through FSB Wealth Management, which operates as a division of First Seacoast Bank. FSB Wealth Management provides access to non-Federal Deposit Insurance Corporation-insured products that include retirement planning, portfolio management, investment and insurance strategies, business retirement plans and college planning to individuals throughout our primary market area. These investments and services are offered through a third-party registered broker-dealer and investment advisor. FSB Wealth Management receives fees from advisory services and commissions on individual investment and insurance products purchased by clients.

First Seacoast Bank is committed to strengthening the communities where it operates while serving the needs of its customers and creating value for the stockholders of First Seacoast Bancorp. We are proud of our longevity in the Seacoast region and we are inspired to influence positive change through charitable contributions, philanthropic initiatives, and investments, including community development lending, housing and homelessness prevention and support of low- to moderate-income individuals and families. Our steadfast commitment to local people, businesses and nonprofit organizations is supported by First Seacoast Bank and by the First Seacoast

2

Community Foundation, Inc. which was established in 2019 in connection with the First Seacoast Bank’s reorganization into the mutual holding company structure.

First Seacoast Bank is subject to comprehensive regulation and examination by the Office of the Comptroller of the Currency.

First Seacoast Bancorp, Inc. is a newly formed Maryland corporation. Following the completion of the conversion and stock offering, First Seacoast Bancorp, Inc. will succeed First Seacoast Bancorp as the publicly traded holding company of First Seacoast Bank. Our executive offices are located at 633 Central Avenue, Dover, New Hampshire 03820 and our telephone number is (603) 742-4680. Our website address is www.firstseacoastbank.com. Information on this website is not and should not be considered a part of this prospectus.

Business Strategy

In 2019, we changed our name to First Seacoast Bank in order to better reflect our commitment to the people and places we serve. We believe that our name change more appropriately aligns with our mission to better serve our market area, and today we continue to enjoy a strong, loyal and positive reputation throughout the Seacoast region.

As a community-minded financial institution, we focus on serving the financial needs of local individuals and businesses by executing a safe and sound, service-oriented business strategy that seeks to produce earnings that increase over time and can be reinvested in our business and communities. Our current business strategy consists of the following:

3

We have pursued the above strategies since we completed our mutual holding company reorganization in 2019, which has allowed us to successfully leverage the proceeds from our initial public offering. We intend to continue to pursue these business strategies, subject to changes necessitated by future market conditions, regulatory restrictions and other factors. COVID-19 has impacted economic conditions, customer behaviors, credit and asset quality and liquidity. While we are committed to the business strategies noted above, we recognize the challenges and uncertainties of the current environment and plan to execute these strategies as market conditions allow.

Impact of COVID-19 Pandemic

Although the domestic and global economies have largely recovered from the COVID-19 pandemic as many health and safety restrictions have been lifted and vaccine distribution has increased, certain adverse consequences of the pandemic continue to impact the macroeconomic environment and may persist for some time, including labor shortages and disruptions of global supply chains. The growth in economic activity and in the demand for goods and services, coupled with labor shortages and supply chain disruptions, has also contributed to rising inflationary pressures and the risk of recession. Given the continued uncertainty and evolving economic effects and social impacts of the COVID-19 pandemic, the future direct and indirect impacts on our business, results of operations and financial condition are uncertain. See “Risk Factors – Risks Related to the COVID-19 Pandemic – The economic impact of the COVID-19 pandemic could adversely affect our financial condition and results of operations.”

We participated in the Paycheck Protection Program administered by the U.S. Small Business Administration. During the years ended December 31, 2020 and 2021, when the program was in effect, we originated 420 loans with an aggregate principal balance of $46.1 million. At June 30, 2022, the remaining outstanding principal balance of loans originated under this program was $139,000.

Reasons for the Conversion and Stock Offering

Our primary reasons for converting to the fully public stock form of ownership and undertaking the stock offering are to:

4

Potential Withdrawal from Defined Benefit Pension Plan

The capital raised in the stock offering will also offset the impact to capital of the cost associated with First Seacoast Bank’s potential withdrawal from the defined benefit pension plan in which it participates. First Seacoast Bank participates in a multi-employer defined benefit pension plan. First Seacoast Bank has provided notice of its intent to withdraw as a participant from the pension plan as of September 30, 2022. Based on an estimate provided in August 2022 by the plan administrator, the estimated total cost (pre-tax) to withdraw is $2.5 million. Because the cost of withdrawal would primarily depend on the value of the plan’s assets and applicable interest rates at the time of withdrawal, the actual withdrawal cost will not be known until the withdrawal date, which we anticipate would be during the first quarter of 2023. The actual cost could differ significantly from the estimated cost provided by the plan administrator.

Terms of the Stock Offering

We are offering for sale between 2,805,000 and 3,795,000 shares of common stock to eligible depositors and borrowers of First Seacoast Bank, to our tax-qualified employee benefit plans and, to the extent shares remain available, in a community offering to the general public, with a preference given first to natural persons (including trusts of natural persons) residing in the New Hampshire counties of Rockingham and Strafford, and then to existing public stockholders of First Seacoast Bancorp as of the close of business on ________, 2022. If necessary, we will also offer for sale shares to the general public in a syndicated community offering. Unless the number of shares of common stock to be offered is increased to more than 3,795,000 shares or decreased to less than 2,805,000 shares,

5

or the subscription and community offerings are extended beyond                 , 2023, subscribers will not have the opportunity to change or cancel their stock orders once submitted. If the subscription and community offerings are extended beyond                 , 2023, all subscribers will be notified and given an opportunity to confirm, change or cancel their orders. All subscribers will be notified by mail sent to the address the subscriber provides on the stock order form they have submitted. If you do not respond to the notice of extension, your order will be cancelled and we will promptly return your funds with interest at             % per annum or cancel your deposit account withdrawal authorization. If the number of shares to be sold is increased to more than 3,795,000 shares or decreased to less than 2,805,000 shares, all subscribers’ stock orders will be canceled, their withdrawal authorizations will be canceled and funds delivered to us to purchase shares of common stock in the subscription and community offerings will be returned promptly with interest at             % per annum. We will then resolicit subscribers, giving them an opportunity to place new orders for a period of time. No shares purchased in the subscription offering and community offering will be issued until the completion of any syndicated community offering.

The purchase price of each share of common stock offered for sale in the stock offering is $10.00. All investors will pay the same purchase price per share, regardless of whether the shares are purchased in the subscription offering, the community offering or a syndicated community offering. Investors will not be charged a commission to purchase shares of common stock in the stock offering. Keefe, Bruyette & Woods, Inc., our marketing agent in the stock offering, will use its best efforts to assist us in selling shares of our common stock in the stock offering but is not obligated to purchase any shares of common stock in the stock offering.

How We Determined the Offering Range, the Exchange Ratio and the $10.00 Per Share Purchase Price

The amount of common stock we are offering for sale and the exchange ratio for the exchange of shares of First Seacoast Bancorp for shares of First Seacoast Bancorp, Inc. are based on an independent appraisal of the estimated market value of First Seacoast Bancorp, Inc., assuming the stock offering has been completed. Feldman Financial Advisors, Inc., our independent appraiser, has estimated that, as of August 26, 2022, this market value was $59.7 million. Based on federal regulations, this market value forms the midpoint of a valuation range with a minimum of $50.8 million and a maximum of $68.7 million. Based on this valuation range, the 55.2% ownership interest of First Seacoast, MHC in First Seacoast Bancorp as of June 30, 2022 being sold in the stock offering, certain assets held by First Seacoast Bancorp, MHC and the $10.00 per share price, the number of shares of common stock being offered for sale by First Seacoast Bancorp, Inc. ranges from 2,805,000 shares to 3,795,000 shares. The purchase price of $10.00 per share was selected primarily because it is the price most commonly used in mutual-to-stock conversions of financial institutions. The exchange ratio ranges from 0.8358 shares of First Seacoast Bancorp, Inc. common stock for each share of First Seacoast Bancorp common stock at the minimum of the offering range to 1.1308 shares of First Seacoast Bancorp, Inc. common stock for each share of First Seacoast Bancorp common stock at the maximum of the offering range, and will generally preserve in First Seacoast Bancorp, Inc. the percentage ownership of public stockholders in First Seacoast Bancorp immediately before the completion of the conversion and stock offering. Feldman Financial Advisors, Inc. will update its appraisal before we complete the conversion and stock offering. If our pro forma market value at that time is either below $50.8 million or above $68.7 million, then, after consulting with the Federal Reserve Board, we may: terminate the stock offering and promptly return all funds with interest; set a new offering range and give all subscribers the opportunity to place a new order; or take such other actions as may be permitted by the Federal Reserve Board and the Securities and Exchange Commission.

The appraisal is based in part on First Seacoast Bancorp’s financial condition and results of operations, the pro forma effect of the additional capital raised by the sale of shares of common stock in the stock offering, and an analysis of a peer group of 10 publicly traded savings and loan and bank holding companies that Feldman Financial Advisors, Inc. considers comparable to First Seacoast Bancorp. The appraisal peer group consists of the following companies, all of which are traded on the Nasdaq Stock Market.

6

The following table presents a summary of selected pricing ratios for First Seacoast Bancorp, Inc. (on a pro forma basis) as of and for the twelve months ended June 30, 2022, and for the peer group companies based on earnings and other information as of and for the twelve months ended June 30, 2022, with stock prices as of August 26, 2022, as reflected in the appraisal report. Compared to the average pricing of the peer group, and based upon the information in the following table, our pro forma pricing ratios at the midpoint of the offering range indicated a discount of 16.7% on a price-to-book value basis, a discount of 18.4% on a price-to-tangible book value basis, and a premium of 63.9% on a price-to-earnings basis.

The independent appraisal does not indicate trading market value. Do not assume or expect that our valuation as indicated in the appraisal means that after the conversion and stock offering the shares of our common stock will trade at or above the $10.00 per share purchase price. Furthermore, the pricing ratios presented in the appraisal were used by Feldman Financial Advisors, Inc. to estimate our pro forma appraised value for regulatory purposes and not to compare the relative value of shares of our common stock with the value of the capital stock of the peer group. The value of the capital stock of a particular company may be affected by a number of factors such as financial performance, asset size and market location.

For a more complete discussion of the amount of common stock we are offering for sale and the independent appraisal, see “The Conversion and Stock Offering—Stock Pricing and Number of Shares to be Issued.”

Effect of First Seacoast Bancorp, MHC’s Assets on Minority Stock Ownership

Public stockholders of First Seacoast Bancorp will receive shares of common stock of First Seacoast Bancorp, Inc. in exchange for their shares of common stock of First Seacoast Bancorp pursuant to an exchange ratio that is designed to provide public stockholders with the same ownership percentage of the common stock of First Seacoast Bancorp, Inc. after the conversion as their ownership percentage in First Seacoast Bancorp immediately before the conversion, without giving effect to new shares purchased in the offering, cash paid in lieu of any

7

fractional shares or the effect of shares issued to the charitable foundation. However, the exchange ratio will be adjusted downward to reflect assets held by First Seacoast Bancorp, MHC (other than shares of common stock of First Seacoast Bancorp) at the completion of the conversion and stock offering, which net assets consist primarily of cash totaling $100,000 at June 30, 2022. This adjustment would decrease First Seacoast Bancorp’s public stockholders’ ownership interest in First Seacoast Bancorp, Inc. from 44.83% to 44.76%, and would increase the ownership interest of persons who purchase stock in the stock offering from 55.17% (the amount of First Seacoast Bancorp’s outstanding stock held by First Seacoast Bancorp, MHC) to 55.24%.

The Exchange of Existing Shares of First Seacoast Bancorp Common Stock

If you are a stockholder of First Seacoast Bancorp immediately before the completion of the conversion and stock offering, your shares will be exchanged for shares of common stock of First Seacoast Bancorp, Inc. The number of shares of common stock you will receive will be based on the exchange ratio, which will depend upon our final appraised value and the percentage of outstanding shares of First Seacoast Bancorp common stock owned by public stockholders immediately before the completion of the conversion and stock offering. The following table shows how the exchange ratio will adjust, based on the appraised value of First Seacoast Bancorp, Inc. as of August 26, 2022, assuming public stockholders of First Seacoast Bancorp own 55.2% of the outstanding shares of First Seacoast Bancorp common stock and First Seacoast Bancorp, MHC had assets (excluding its shares of First Seacoast Bancorp common stock) of $100,000 immediately before the completion of the conversion and stock offering. The table also shows the number of shares of First Seacoast Bancorp, Inc. common stock a hypothetical owner of First Seacoast Bancorp common stock would receive in exchange for 100 shares of First Seacoast Bancorp common stock owned at the completion of the conversion and stock offering, depending on the number of shares of common stock issued in the conversion and stock offering.

No fractional shares of First Seacoast Bancorp, Inc. common stock will be issued to any public stockholder of First Seacoast Bancorp. For each fractional share that otherwise would be issued, First Seacoast Bancorp, Inc. will pay in cash an amount equal to the product obtained by multiplying the fractional share interest to which the holder otherwise would be entitled by the $10.00 per share offering price.

Intended Use of the Proceeds From the Stock Offering

We intend to invest at least 50% of the net proceeds from the stock offering in First Seacoast Bank, fund a loan to our employee stock ownership plan to finance its purchase of shares of common stock in the stock offering and retain the remainder of the net proceeds from the stock offering at First Seacoast Bancorp, Inc. Therefore, assuming we sell 3,300,000 shares of common stock in the stock offering at the midpoint of the offering range resulting in net proceeds of $31.4 million, we intend to invest $15.7 million in First Seacoast Bank, loan $2.6 million to our employee stock ownership plan to fund its purchase of shares of common stock, and retain the remaining $13.1 million of the net proceeds at First Seacoast Bancorp, Inc.

First Seacoast Bancorp, Inc. may use the funds it retains for investment in securities, to repurchase shares of common stock, to acquire other financial institutions or financial services companies, to pay cash dividends and

8

for other general corporate purposes. First Seacoast Bank may use the proceeds it receives to support increased lending, enhance existing, or support growth and the development of, new products and services, or expand its branch network by establishing or acquiring new branches or by acquiring other financial institutions or financial services companies. We do not currently have any agreements or understandings regarding any acquisition transactions.

See “How We Intend to Use the Proceeds from the Stock Offering” for additional information.

Persons Who May Order Shares of Common Stock in the Stock Offering

We are offering the shares of common stock for sale in a subscription offering in the following descending order of priority:

Shares of common stock not purchased in the subscription offering may be offered for sale to the general public in a community offering, with a preference given first to natural persons (including trusts of natural persons) residing in the New Hampshire counties of Rockingham and Strafford, and then to First Seacoast Bancorp’s public stockholders at the close of business on                 , 2022. If held, the community offering is expected to begin concurrently with the subscription offering, but may begin concurrently with, during or promptly after the subscription offering. We also may offer for sale shares of common stock not purchased in the subscription offering and the community offering in a syndicated community offering. Keefe, Bruyette & Woods, Inc. will act as sole manager for the syndicated community offering. We have the right to accept or reject, in our sole discretion, orders received in the community offering or syndicated community offering, and our interpretation of the terms and conditions of the plan of conversion will be final. Any determination to accept or reject stock orders in the community offering or syndicated community offering will be based on the facts and circumstances available to management at the time of the determination.

If we receive orders for more shares than we are offering for sale, we may not be able to fill your order in whole or in part. A detailed description of the subscription offering, the community offering and the syndicated community offering, as well as a discussion regarding allocation procedures, can be found in the section of this prospectus entitled “The Conversion and Stock Offering.”

Limits on How Much Common Stock You May Purchase

The minimum number of shares of common stock that may be purchased is 25 shares.

Generally, no individual, or individuals acting through a single qualifying account held jointly, may purchase more than 40,000 shares ($400,000) of common stock. If any of the following persons purchase shares of common stock, their purchases, in all categories of the stock offering, when combined with your purchases, cannot exceed 40,000 shares ($400,000) of common stock:

9

Unless we determine otherwise, persons having the same address and persons exercising subscription rights through qualifying accounts registered to the same address will be subject to the overall purchase limitation of 40,000 shares ($400,000).

In addition to the above purchase limitations, there is an ownership limitation for current stockholders of First Seacoast Bancorp other than our employee stock ownership plan. Shares of common stock that you purchase in the stock offering individually and together with persons described above, plus any shares you and they receive in exchange for existing shares of First Seacoast Bancorp common stock, may not exceed 9.9% of the total shares of common stock to be issued and outstanding after the completion of the conversion and stock offering. However, if, based on your current ownership level, you will own more than 9.9% of the total shares of common stock of First Seacoast Bancorp, Inc. to be issued and outstanding after the completion of the conversion and stock offering following the exchange of your shares of First Seacoast Bancorp common stock, you will be ineligible to purchase any new shares in the stock offering. You will be required to obtain regulatory approval or non-objection before acquiring 10% or more of First Seacoast Bancorp, Inc.’s common stock.

Subject to regulatory approval, we may increase or decrease the purchase and ownership limitations at any time. See the detailed description of the purchase limitations in “The Conversion and Stock Offering – Additional Limitations on Common Stock Purchases.”

How You May Purchase Shares of Common Stock in the Subscription Offering and the Community Offering

In the subscription offering and any community offering, you may pay for your shares only by:

First Seacoast Bank, by law, is not permitted to lend funds to anyone to purchase shares of common stock in the stock offering. Additionally, you may not use any type of third party check to pay for shares of common stock. Do not submit cash. Wire transfers will not be accepted. Applicable regulations prohibit First Seacoast Bank from lending funds or extending credit to any person to purchase shares of common stock in the stock offering. You may not submit a First Seacoast Bank line of credit check for payment. You may not designate withdrawal from First Seacoast Bank’s accounts with check-writing privileges; rather, submit a check. If you request a direct withdrawal, we reserve the right to interpret that as your authorization to treat those funds as if we had received a check for the designated amount, and will immediately withdraw the amount from your checking account(s). You may not authorize direct withdrawal from a First Seacoast Bank individual retirement account, or IRA. See “—Using Individual Retirement Account Funds to Purchase Shares of Common Stock.”

You may subscribe for shares of common stock in the subscription and community offerings by delivering a signed and completed original stock order form, together with full payment payable to First Seacoast Bancorp, Inc. or authorization to withdraw funds from one or more of your First Seacoast Bank deposit accounts, provided that the

10

stock order form is received before 2:00 p.m., Eastern time, on December ___, 2022, which is the expiration of the subscription offering period. You may submit your stock order form and payment by mail using the stock order reply envelope provided or by paying for overnight delivery to the address listed on the stock order form. You may also hand-deliver stock order forms to our main office, located at 633 Central Avenue, Dover, New Hampshire. Hand-delivered stock order forms will be accepted only at this location. We will not accept stock order forms at other offices of First Seacoast Bank. Do not mail stock order forms to any of First Seacoast Bank’s offices.

See “The Conversion and Stock Offering – Procedure for Purchasing Shares in the Subscription and Community Offerings – Payment for Shares” for a complete description of how to purchase shares in the subscription and community offerings.

Using Individual Retirement Account Funds to Purchase Shares of Common Stock

You may be able to subscribe for shares of common stock using funds in your individual retirement account (“IRA”) or other retirement account. If you wish to use some or all of the funds in your First Seacoast Bank IRA or other retirement account, the applicable funds must be transferred to a self-directed account maintained by an independent custodian or trustee, such as a brokerage firm, and the purchase must be made through that account. If you do not have such an account, you will need to establish one before placing your stock order. An annual administrative fee may be payable to the independent custodian or trustee. Because individual circumstances differ and the processing of retirement fund orders takes additional time, we recommend that you contact our Stock Information Center promptly, preferably at least two weeks before the December ___, 2022 offering deadline, for assistance with purchases using funds in your IRA or other retirement account you may have at First Seacoast Bank or elsewhere. Whether you may use such funds to purchase shares in the stock offering may depend on timing constraints and, possibly, limitations imposed by the institution where the funds are held.

See “The Conversion and Stock Offering – Procedure for Purchasing Shares in the Subscription and Community Offerings – Payment for Shares” and “—Using Individual Retirement Account Funds” for a complete description of how to use IRA funds to purchase shares of common stock in the stock offering.

offering range. The purchase price paid by them will be the same $10.00 per share price paid by all other persons who purchase shares of common stock in the stock offering. Following the conversion and stock offering, our directors and executive officers, together with their associates, are expected to beneficially own 115,596 shares of common stock of First Seacoast Bancorp, Inc., or 2.3% of our total outstanding shares of common stock at the minimum of the offering range, which includes shares they currently own in First Seacoast Bancorp that will be exchanged for shares of First Seacoast Bancorp, Inc.

See “Subscriptions by Directors and Executive Officers” for more information on the proposed purchases of shares of common stock by our directors and executive officers.

Deadline for Orders of Shares of Common Stock in the Subscription and Community Offerings

The deadline for submitting orders to purchase shares of common stock in the subscription offerings and, if held, in the community officering is 2:00 p.m., Eastern time, on December     , 2022, unless we extend this deadline. If you wish to purchase shares of common stock, a properly completed and signed original stock order form, together with full payment, must be received (not postmarked) by this time.

Although we will make reasonable attempts to provide this prospectus and offering materials to holders of subscription rights, the subscription offering and all subscription rights will expire at 2:00 p.m., Eastern time, on December     , 2022, whether or not we have been able to locate each person entitled to subscription rights.

See “The Conversion and Stock Offering – Procedure for Purchasing Shares in the Subscription and Community Offerings – Expiration Date” for a complete description of the deadline for purchasing shares in the stock offering.

You May Not Sell or Transfer Your Subscription Rights

Applicable regulations prohibit you from transferring your subscription rights. If you order shares of common stock in the subscription offering, you will be required to certify that you are purchasing the common stock for yourself and that you have no agreement or understanding to sell or transfer your subscription rights or the shares that you are purchasing. We intend to take legal action, including reporting persons to federal or state agencies, against anyone who we believe has sold or transferred his or her subscription rights. We will not accept your order if we have reason to believe you have sold or transferred your subscription rights. On the stock order form, you cannot add the names of others for joint stock registration who do not have subscription rights or who qualify only in a lower subscription offering priority than you do. Doing so may jeopardize your subscription rights. You may only add those who were eligible to purchase shares of common stock in the subscription offering at your date of eligibility. In addition, the stock order form requires that you list all deposit and loan accounts, giving all names on each account and the account number at the applicable eligibility date. Failure to provide this information, or providing incomplete or incorrect information, may result in a loss of part or all of your share allocation.

Delivery of Shares of Common Stock

All shares of common stock sold will be issued in book entry form. Stock certificates will not be issued. A statement reflecting ownership of shares of common stock issued in the subscription and community offerings will be mailed by our transfer agent to the persons entitled thereto at the registration address noted by them on their stock order forms as soon as practicable following consummation of the conversion and stock offering. We expect trading in the stock to begin on the day of completion of the conversion and stock offering or the next business day. The conversion and stock offering is expected to be completed as soon as practicable following satisfaction of the conditions described below in “—Conditions to Completion of the Conversion and Stock Offering.” Until a statement reflecting your ownership of shares of common stock is available and delivered to you, you may not be able to sell the shares of common stock that you purchased in the stock offering, even though the common stock will have begun trading. Your ability to sell your shares of common stock before receiving your statement will depend on arrangements you may make with a brokerage firm.

12

Conditions to Completion of the Conversion and Stock Offering

We cannot complete the conversion and stock offering unless:

First Seacoast Bancorp, MHC intends to vote its shares in favor of the plan of conversion. At the close of business on June 30, 2022, First Seacoast Bancorp, MHC owned 3,345,925 shares, or approximately 55.2%, of the outstanding shares of common stock of First Seacoast Bancorp. At the close of business on June 30, 2022, the directors and executive officers of First Seacoast Bancorp and their affiliates owned 87,462 shares of First Seacoast Bancorp common stock, or 1.44% of the outstanding shares of common stock and 3.22% of the outstanding shares of common stock excluding the shares owned by First Seacoast Bancorp, MHC. They intend to vote those shares in favor of the plan of conversion.

Steps We May Take if We Do Not Receive Orders for the Minimum Number of Shares

If we do not receive orders for at least 2,805,000 shares of common stock, we may take one or more steps to sell the minimum number of shares of common stock in the offering range. Specifically, we may:

If we extend the stock offering past _________, 2023, all subscribers will be notified and given an opportunity to confirm, change or cancel their orders. If you do not respond to the notice of extension, we will cancel your stock order and promptly return your funds with interest for funds received in the subscription offering and, if held, the community offering or cancel your deposit account withdrawal authorization. If one or more purchase limitations are increased, subscribers in the subscription offering who ordered the maximum amount and who indicated a desire to be resolicited on the stock order form will be, and, in our sole discretion, some other large subscribers may be, given the opportunity to increase their subscriptions up to the then-applicable limit.

13

Possible Change in the Offering Range

Feldman Financial Advisors, Inc. will update its appraisal before we complete the conversion and stock offering. If our pro forma market value at that time is either below $50.8 million or above $68.7 million, then, after consulting with the Federal Reserve Board, we may:

If we set a new offering range, we will promptly return funds, with interest at _____% per annum, for funds received for purchases in the subscription offering and any community offering, and cancel any authorization to withdraw funds from deposit accounts for the purchase of shares of common stock. We will then resolicit subscribers, allowing them to place a new stock order for a period of time.

Possible Termination of the Stock Offering

We may terminate the stock offering at any time before the special meeting of members of First Seacoast Bancorp, MHC and the special meeting of stockholders of First Seacoast Bancorp that have been called to vote on the conversion and stock offering, and at any time after these approvals with regulatory approval. If we terminate the stock offering, we will promptly return your funds with interest at _____% per annum, and we will cancel deposit account withdrawal authorizations.

Benefits to Management and Potential Dilution to Stockholders Resulting from the Conversion and Stock Offering

We expect our employee stock ownership plan, which is a tax-qualified retirement plan for the benefit of First Seacoast Bank’s employees, to purchase up to 8% of the shares of common stock we sell in the stock offering. If market conditions warrant, in the judgment of its trustees, the employee stock ownership plan’s subscription order will not be filled and the employee stock ownership plan may elect to purchase shares in the open market following the completion of the conversion and stock offering, subject to the approval of the Federal Reserve Board.

We intend to implement one or more new stock-based benefit plans no earlier than six months after completion of the conversion and stock offering. Stockholder approval of these plans would be required. We have not determined whether we would adopt the plans within or after 12 months following the completion of the conversion and stock offering. If we implement stock-based benefit plans within 12 months following the completion of the conversion and stock offering, the stock-based benefit plans would be limited to reserving a number of shares (i) up to 4% of the shares of common stock sold in the stock offering for awards of restricted stock to key employees and directors, at no cost to the recipients, and (ii) up to 10% of the shares of common stock sold in the stock offering for issuance pursuant to the exercise of stock options by key employees and directors. If the stock-based benefit plan is adopted more than 12 months after the completion of the conversion and stock offering, it would not be subject to the percentage limitations set forth above. We have not yet determined the definitive number of shares that would be reserved for issuance under these plans. For a description of our current stock-based benefit plan, see “Management – Benefits to be Considered Following Completion of the Conversion and Stock Offering – Stock-Based Benefit Plans.”

The following table summarizes the number of shares of common stock and the aggregate dollar value of grants that are available under one or more stock-based benefit plans if such plans reserve a number of shares of common stock equal to 4% and 10% of the shares sold in the stock offering for restricted stock awards and stock options, respectively. The table shows the dilution to stockholders if all such shares are issued from authorized but unissued shares, instead of shares purchased in the open market. A portion of the stock grants shown in the table

14

below may be made to non-management employees. The table also sets forth the number of shares of common stock to be acquired by the employee stock ownership plan for allocation to all qualifying employees.

We may fund our stock-based benefit plans through open market purchases, as opposed to new issuances of stock; however, if any options previously granted under our existing 2021 Equity Incentive Plan are exercised during the first year following completion of the stock offering, they will be funded with newly issued shares as federal regulations do not permit us to repurchase our shares during the first year following the completion of the stock offering except to fund the grants of restricted stock under a stock-based benefit plan or under extraordinary circumstances.

The following table presents information as of June 30, 2022 regarding our employee stock ownership plan, our 2021 Equity Incentive Plan, and our proposed stock-based benefit plan. The table below assumes that 6,869,548 shares are outstanding after the completion of the stock offering, which includes the sale of 3,795,000 shares in the stock offering at the maximum of the offering range and the issuance of shares of First Seacoast Bancorp, Inc. in exchange for shares of First Seacoast Bancorp based on an exchange ratio of 1.1308. It also assumes that the value of the common stock is $10.00 per share.

15

Income Tax Consequences

First Seacoast Bancorp, MHC, First Seacoast Bancorp, First Seacoast Bank, and First Seacoast Bancorp, Inc. have received an opinion of counsel, Luse Gorman, PC, regarding the material federal income tax consequences of the conversion and stock offering, and have received an opinion of Baker Newman & Noyes LLC regarding the material New Hampshire tax consequences of the conversion and stock offering. As a general matter, the conversion and stock offering will not be a taxable transaction for purposes of federal or state income taxes to First Seacoast Bancorp, MHC, First Seacoast Bancorp, First Seacoast Bank, and First Seacoast Bancorp, Inc., persons eligible to subscribe in the subscription offering, or existing stockholders of First Seacoast Bancorp (except as to cash paid for fractional shares). Existing stockholders of First Seacoast Bancorp who receive cash in lieu of fractional shares of First Seacoast Bancorp, Inc. will recognize a gain or loss equal to the difference between the cash received and the tax basis of the fractional share.

Emerging Growth Company Status

We qualify as an “emerging growth company” under the Jumpstart Our Business Startups Act of 2012. For as long as we are an emerging growth company, we may choose to take advantage of exemptions from various reporting requirements applicable to other public companies but not to emerging growth companies. See “Risk Factors – Risks Related to Our Business – We are an emerging growth company, and any decision on our part to comply only with certain reduced reporting and disclosure requirements applicable to emerging growth companies could make our common stock less attractive to investors” and “Supervision and Regulation – Emerging Growth Company Status.”

An emerging growth company may elect to use the extended transition period to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies, but must make such election when the company is first required to file a registration statement. Such an election is irrevocable during the period a company is an emerging growth company. We have elected to use the extended transition period to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. Accordingly, our financial statements may not be comparable to the financial statements of public companies that comply with such new or revised accounting standards.