Marathon Bancorp Inc MD

As filed with the Securities and Exchange Commission on December 13, 2024

Registration No. 333-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM****S-1

REGISTRATION STATEMENT UNDER THE

SECURITIES ACT OF 1933

Marathon Bancorp, Inc.** and**

Marathon Bank 401(k) Plan

(Exact Name of Registrant as Specified in Its Charter)

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Nicholas W. Zillges

President and Chief Executive Officer

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Copies to:

**Approximate date of commencement of proposed sale to the public:**As soon as practicable after this registration statement becomes effective.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box:☒

If this Form is filed to register additional shares for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided to Section 7(a)(2)(B) of the Securities Act.☐

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

Prospectus Supplement

MARATHON BANK 401(k) PLAN

Offering of Participation Interests in up to 427,710 Shares

of

Common Stock

Marathon Bancorp, Inc., a Maryland corporation that we refer to as “Marathon Bancorp” throughout this prospectus supplement, is offering shares of common stock for sale at $10.00 per share in connection with the conversion of Marathon MHC, which we refer to as the “MHC” throughout this prospectus supplement, from the mutual holding company to the stock holding company form of organization. The shares being offered represent the ownership interest in Marathon Bancorp, for which the MHC currently owns more than 50% of the outstanding shares. Marathon Bancorp’s common stock currently trades on the Pink Open Market, operated by OTC Markets Group under the trading symbol “MBBC.” Following the offering, we expect Marathon Bancorp’s common stock will trade on the NASDAQ Capital Market also under the trading symbol “MBBC.” We must sell a minimum of 1,402,142 shares to complete the offering.

In connection with the stock offering, Marathon Bank is allowing participants in the Marathon Bank 401(k) Plan (the “401(k) Plan”) to invest all or a portion of their account balances in Marathon Bancorp common stock. Based upon the value of the 401(k) Plan assets at December 31, 2023, the trustee of the 401(k) Plan could purchase up to 427,710 shares of Marathon Bancorp common stock, at the purchase price of $10.00 per share, in the stock offering. This prospectus supplement relates to the election of 401(k) Plan participants to direct the trustee of the 401(k) Plan to invest all or a portion of their 401(k) Plan account balances in Marathon Bancorp common stock at the time of the stock offering.

Before you consider investing, you should read the prospectus of Marathon Bancorp, dated [prospectus date], which is attached to this prospectus supplement. It contains detailed information regarding the conversion, the stock offering of Marathon Bancorp and the financial condition, results of operations and business of Marathon Bank. This prospectus supplement provides information regarding the 401(k) Plan. You should read this prospectus supplement together with the prospectus and keep both for future reference.

For a discussion of risks that you should consider, see “Risk Factors” beginning on page1** in this prospectus supplement, “Risk Factors” beginning on page16 of the attached prospectus, and “Notice of Your Rights Concerning Employer Securities” in this prospectus supplement.**

The interests in the 401(k) Plan and the offering of the shares of Marathon Bancorp common stock have not been approved or disapproved by the Federal Deposit Insurance Corporation, the Board of Governors of the Federal Reserve System, the Wisconsin Department of Financial Institutions, the Securities and Exchange Commission or any other federal or state agency. Any representation to the contrary is a criminal offense.

The securities offered by this prospectus supplement are not deposits or savings accounts and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.

This prospectus supplement may be used only in connection with offers and sales by Marathon Bancorp in the stock offering of Marathon Bancorp common stock that may be acquired within the 401(k) Plan. No one may use this prospectus supplement to reoffer or resell interests in shares of Marathon Bancorp common stock acquired through the 401(k) Plan.

You should rely only on the information contained in this prospectus supplement and the attached prospectus. Marathon Bancorp, Marathon Bank, and the 401(k) Plan have not authorized anyone to provide you with different information.

This prospectus supplement does not constitute an offer to sell or solicitation of an offer to buy any securities in any jurisdiction to any person to whom it is unlawful to make an offer or solicitation in that jurisdiction. Neither the delivery of this prospectus supplement and the attached prospectus nor any sale of Marathon Bancorp common stock shall under any circumstances imply that there has been no change in the affairs of Marathon Bancorp, Marathon Bank or the 401(k) Plan since the date of this prospectus supplement, or that the information contained in this prospectus supplement or incorporated by reference is correct as of any time after the date of this prospectus supplement.

The date of this prospectus supplement is ____________, 2025.