Marathon Bancorp, Inc. /MD/

BUSINESS OF MARATHON BANCORP, INC.

Marathon Bancorp, Inc. (the “Company” or “Marathon Bancorp”), a Maryland corporation, was formed in December 2020 to serve as the mid-tier holding company for Marathon Bank (the “Bank”) upon the completion of the Bank’s mutual holding company reorganization and offering.

On April 14, 2021, the Bank completed its reorganization into the mutual holding company structure and the related stock offering of the Company, the Bank’s new holding company. As a result of the reorganization, the Bank became a wholly-owned subsidiary of the Company, the Company issued and sold 45.0% of its outstanding shares of common stock in its stock offering to the public, and the Company issued 55.0% of its outstanding shares of common stock to Marathon MHC (“Mutual Holding Company”), which was the Company’s mutual holding company.

On April 21, 2025, the Company completed its conversion from the mutual holding company form of organization to the stock holding company form of organization (the “Conversion”). In connection with the Conversion, the Mutual Holding Company ceased to exist. Also, as part of the Conversion, the Company sold 1,693,411 shares of its common stock, which included 135,472 shares issued to the Employee Stock Ownership Plan (“ESOP”), at a price of $10.00 per share to the public. Each outstanding share of Company common stock owned by the public stockholders of the Company (stockholders other than the Mutual Holding Company) were converted into new shares of Company common stock based on an exchange ratio of 1.3728-to-1. Following the completion of the Conversion, the Company’s shares of common stock began trading on the Nasdaq Capital Market under the trading symbol “MBBC.”

The Company generated gross proceeds of $16.9 million from the Conversion. Offering expenses in connection with the Conversion were $1.7 million which were netted against the gross proceeds.

In connection with the Conversion, the Company provided a term loan to the ESOP to finance the ESOP’s purchase of the 135,472 shares noted above. The Company combined its existing outstanding ESOP loan in the amount of $777,212 with this new loan resulting in a new term loan to the ESOP of $2.1 million which will be repaid in annual installments over 25 years.

Finally, as a result of the Conversion, all existing stock options and restricted stock awards outstanding on April 21, 2025 were adjusted based on the exchange ratio of 1.3728-to-1. All historical share and per share information prior to the completion of the Conversion also has been restated to reflect the 1.3728-to-1 exchange ratio.

Marathon Bancorp, as the holding company of Marathon Bank, is authorized to pursue other business activities permitted by applicable laws and regulations for bank holding companies, which may include the acquisition of banking and financial services companies. The Company is subject to comprehensive regulation and examination by the Board of Governors of the Federal Reserve System (the “Federal Reserve Board”) and the Wisconsin Department of Financial Institutions (the “WDFI”).

Our cash flow depends on earnings from the investment of the net proceeds we retained, and any dividends received from Marathon Bank. Currently, Marathon Bancorp does not own nor lease any property, but instead uses the premises, equipment and furniture of Marathon Bank. At the present time, we employ only persons who are officers of Marathon Bank to serve as officers of Marathon Bancorp. We also use the support staff of Marathon Bank from time to time. These persons are not separately compensated by Marathon Bancorp. Marathon Bancorp may hire additional employees, as appropriate, to the extent it expands its business in the future. The directors of Marathon Bancorp consist of the current directors of Marathon Bank.

The Company files interim, quarterly and annual reports with the Securities and Exchange Commission (the “SEC”). The SEC maintains an Internet site (www.sec.gov) that contains reports, proxy and information statements and other information regarding issuers such as the Company that file electronically with the SEC. All filed SEC reports and

interim filings can also be obtained from the Company’s websitewww.marathonbancorp.com on the “Investor Relations” page, without charge from the Company.

BUSINESS OF MARATHON BANK

General

Marathon Bank is a Wisconsin-chartered savings bank headquartered in Wausau, Wisconsin. Founded in 1902, we conduct our business from our main office and four branch offices, which are located in Marathon, Ozaukee and Waukesha Counties, Wisconsin. Our primary market area for deposits includes the communities in which we maintain our banking office locations, while our primary lending market area is broader and includes select businesses and customers in Southeastern Wisconsin. We are a community-oriented bank offering a variety of financial products and services to meet the needs of our customers. We believe that our community orientation and personalized service distinguishes us from larger banks that operate in our market area.

From our founding until 2014, we operated as a traditional thrift institution, offering primarily residential mortgage loans and savings accounts. In February 2014, we hired our current president and chief executive officer, Nicholas W. Zillges, and since that time we have strengthened and modernized our operations through upgrades to our credit, underwriting, information technology and compliance operations. Under the leadership of Mr. Zillges, we have developed a commercial real estate lending infrastructure, with a particular focus on expanding into the Southeastern Wisconsin market, including the Milwaukee metropolitan area, to grow our commercial real estate and multifamily loan portfolios. As part of our effort to expand into Southeastern Wisconsin, in 2024, we opened a new branch in Brookfield, Wisconsin and in 2018, we opened a branch in Mequon, Wisconsin. We anticipate opening a new branch in New Holstein, Wisconsin in the fourth quarter of 2026. Additionally, consistent with our strategy to grow our commercial loan operations, we have enhanced our suite of deposit products, including remote deposit capture, commercial cash management and mobile deposits in order to accommodate business customers, and thereby grow our core deposits. While we have developed our commercial real estate platform in recent years, we also remain committed to our local community and intend to continue to be a significant one- to four-family residential mortgage lender in our market areas subject to market conditions and the interest rate environment.

Our business consists primarily of taking deposits from the general public and investing those deposits, together with funds generated from operations, in commercial and multifamily real estate loans, one- to four-family residential real estate loans and, to a lesser extent, commercial and industrial loans, construction loans and consumer loans. Subject to market conditions, we expect to continue our focus on originating commercial real estate and multifamily real estate loans in an effort to further increase the overall yield earned on our loans and assist in managing interest rate risk. We also invest in debt securities, which have historically consisted of mortgage-backed securities issued by U.S. government sponsored enterprises, municipal securities, corporate debt securities and U.S. government and agency securities. We offer a variety of deposit accounts, including checking accounts, savings accounts, money market accounts and certificate of deposit accounts. We borrow funds, primarily from the Federal Home Loan Bank of Chicago, to fund our operations as necessary.

At June 30, 2026, we had total consolidated assets of $261.0 million, total deposits of $189.8 million and total stockholders’ equity of $48.0 million. Our executive office is located at 500 Scott Street, Wausau, Wisconsin 53226, and our telephone number at this address is (715) 845-7331. Our website address iswww.marathonbank.com. Information on our website is not and should not be considered a part of this Form 10-K.

Market Area

We conduct our business from our main office and four branch offices, which are located in Marathon, Ozaukee and Waukesha Counties, Wisconsin. Our primary market area is broadly defined as the Wausau, Wisconsin metropolitan area, including Marathon, Ozaukee and Waukesha Counties. In recent years, we have expanded our operations into Southeastern Wisconsin, primarily Milwaukee and Waukesha counties. We expect further growth in the Southeastern Wisconsin market area, including the Milwaukee metropolitan area. The following discusses the demographics of the counties in which we operate.

Marathon County’s total population for 2026 is estimated at 139,770, approximately 4.26% growth since 2010. A relatively high percentage of Marathon County’s non-farm, non-government workforce is in the retail trade, education, healthcare and manufacturing sectors, estimated at 70-80% of the labor force. Other significant employer industries in the county include transportation and utilities, finance/insurance and leisure and hospitality. Median household income for 2026 in Marathon County is estimated to be $77,884.

Ozaukee County’s total population for 2026 is estimated at 95,027, approximately 9.20% growth since 2010. Manufacturing, education and healthcare represent over 45.5% of the labor force. Other significant employer industries in Ozaukee County include transportation and utilities, professional and business services, leisure and hospitality and senior living health related services. Median household income for 2026 in Ozaukee County is estimated to be $96,996.

Milwaukee County’s total population for 2026 is estimated at 924,109, an approximately 2.58% decrease since 2010. Milwaukee County’s most significant employers are in the industrial manufacturing, education, healthcare, trade, transportation and utilities industries. Median household income for 2026 in Milwaukee County is estimated to be $64,435.

Waukesha County’s total population for 2026 is estimated at 418,654, approximately 7.30% growth since 2010. The most significant employers in Waukesha County are in the manufacturing, education, health care, transportation and utilities, professional and business services, leisure and hospitality and industrial technology industries. Waukesha County has the highest median household income of any of Marathon Bank’s market area counties, estimated to be $106,076 for 2026.

Unemployment rates as of June 30, 2026 and June 30, 2025 are set forth in the following table.

Major employers in Marathon Bank’s market area are United Medical Resources, Stryker, Aspirus, Advocate Aurora Health, Ascension-Wisconsin, ABB Campus, Linetec, Froedtert ThedaCare, Quad/Graphics, Inc., Kohl’s, Northwestern Mutual and Rockwell Automation.

Competition

We face competition within our market area both in making loans and attracting deposits. Our market area has a concentration of financial institutions that include large money center and regional banks, community banks and credit unions. We also face competition from savings institutions, mortgage banking firms, consumer finance companies and credit unions and, with respect to deposits, from money market funds, brokerage firms, mutual funds and insurance companies. We also compete with fintech and internet banking companies. Some of our competitors offer products and services that we currently do not offer, such as trust services and private banking. As of June 30, 2025 (the most recent date for which data is available), our market share of deposits represented 2.99% of FDIC-insured deposits in Marathon County, ranking us ninth in market share of deposits out of 17 institutions operating in the county. In addition, as of that date, our market share of deposits represented 0.53% of FDIC-insured deposits in Ozaukee County, ranking us 13th in market share of deposits out of 15 institutions operating in the county. Finally, as of that date, our market share of deposits represented 0.06% of FDIC-insured deposits in Waukesha County, ranking us 34th in market share of deposits out of 34 institutions operating in the county. The June 30, 2026 market share of deposits data is not available yet.

Lending Activities

General. Our lending activity consists of originating commercial and multifamily real estate loans, one- to four-family residential real estate loans and, to a lesser extent, commercial and industrial loans, construction loans and consumer loans. Subject to market conditions, we intend to increase originations of commercial real estate loans and multifamily real estate loans in order to increase the overall yield earned on our loans and manage interest rate risk.

We generally sell the fixed-rate conforming one- to four-family residential real estate loans that we originate, generally on a servicing-retained basis, while holding in our portfolio adjustable-rate one- to four-family residential real estate loans in order to manage the duration and time to repricing of our loan portfolio.

Loan Portfolio Composition. The following table sets forth the composition of our loan portfolio by type of loan at the dates indicated.

Contractual Maturities. The following tables set forth the contractual maturities of our total loan portfolio at June 30, 2026. Demand loans, loans having no stated repayment schedule or maturity, and overdraft loans are reported as being due in one year or less. The tables present contractual maturities and do not reflect repricing or the effect of prepayments. Actual maturities may differ. These tables exclude loans held for sale.

The following table sets forth our fixed and adjustable-rate loans at June 30, 2026 that are contractually due after June 30, 2027. Our balloon loans are included as fixed-rate loans for purposes of this table.

Commercial Real Estate Lending**.** Consistent with our strategy to grow our loan portfolio and increase our yield, we are focused on increasing our origination of commercial real estate loans. At June 30, 2026, we had $95.9 million in commercial real estate loans, representing 43.7% of our total loan portfolio. Our commercial real estate loans are generally secured by office and industrial buildings, warehouses, small retail facilities and other special purpose commercial properties, primarily in Southeastern Wisconsin. At June 30, 2026, $85.2 million of our commercial real estate portfolio was secured by non-owner-occupied commercial real estate.

Our commercial real estate loans generally are fixed rate, have initial terms of five years and amortization periods of up to 30 years, with a balloon payment due at the end of the initial term. The maximum loan-to-value ratio of our commercial real estate loans is generally 75% of the lower of cost or appraised value of the property securing the loan.

At June 30, 2026, the average loan size of our commercial real estate loans was $999,000, and the largest of such loans was a $4.9 million loan secured by a restaurant. This loan was performing in accordance with its repayment terms at June 30, 2026.

The following table presents the commercial real estate portfolio by industry sector at June 30, 2026 and 2025.

We consider a number of factors in originating commercial real estate loans. We evaluate the qualifications and financial condition of the borrower, including project-level and global cash flows, credit history, and management expertise, as well as the value and condition of the property securing the loan. When evaluating the qualifications of the borrower, we consider the financial resources of the borrower, the borrower’s experience in owning or managing similar property and the borrower’s payment history with us and other financial institutions. In evaluating the property securing the loan, the factors we consider include the net operating income of the mortgaged property before debt service and depreciation, the ratio of the loan amount to the appraised value of the mortgaged property and the debt service coverage ratio (the ratio of net operating income to debt service). We generally require a debt service ratio of at least 1.25x. All commercial real estate loans of $500,000 or more are appraised by outside independent appraisers.

Personal guarantees are generally obtained from the principals of commercial real estate loans. We require property and casualty insurance and flood insurance if the property is determined to be in a flood zone area.

Multifamily Real Estate Loans. At June 30, 2026, multifamily real estate loans were $53.9 million, or 24.6%, of our total loan portfolio which was partly due to our purchases of participation interests in multifamily real estate loans totaling $6.0 million. Our multifamily real estate loans are generally secured by properties consisting of five or more rental units in our market area. Our multifamily real estate loans generally have fixed rates, initial terms of five years and amortization periods of up to 30 years, with a balloon payment due at the end of the initial term. Virtually all of our multifamily real estate loans are secured by properties located within our primary lending markets in Wisconsin.

At June 30, 2026, the average loan size of our multifamily real estate loans was $1.1 million and the largest of such loans was an approximately $4.5 million loan secured by multiple non-owner-occupied rental properties. This loan was performing in accordance with its repayment terms at June 30, 2026.

In underwriting multifamily real estate loans, we consider a number of factors, which include the projected net cash flow to the loan’s debt service requirement (generally requiring a minimum of 125%), the age and condition of the collateral, the financial resources and income level of the borrower and the borrower’s experience in owning or managing similar properties. Multifamily real estate loans are generally originated in amounts up to 80% of the appraised value or the purchase price of the property securing the loan, whichever is lower. When circumstances warrant, guarantees are obtained from multifamily real estate customers. In addition, the borrower’s and guarantor’s financial information on such loans is monitored on an ongoing basis by requiring periodic financial statement updates. Underwriting for our multifamily loan participations is the same as for those internally originated.

One- to Four-Family Residential Real Estate Lending**.** At June 30, 2026, we had $63.5 million of loans secured by one- to four-family residential real estate, representing 29.0% of our total loan portfolio, which included no residential mortgages held for sale. We originate both fixed-rate and adjustable-rate one- to four-family residential real estate loans. At June 30, 2026, 27.9% of our one- to four-family residential real estate loans were fixed-rate loans, and 72.1% of such loans were adjustable-rate loans. At June 30, 2026, $3.1 million of our loans secured by one- to four-family residential real estate were in a junior lien position.

Our fixed-rate one- to four-family residential real estate loans typically have terms of 10 to 30 years and are generally underwritten according to Fannie Mae guidelines when the loan balance meets such guidelines, and we refer to loans that conform to such guidelines as “conforming loans.” We generally originate both fixed- and adjustable-rate mortgage loans in amounts up to the maximum conforming loan limits as established by the Federal Housing Finance Agency, which as of June 30, 2026 was $832,750 for single-family homes in our market area. We typically sell our conforming fixed-rate one- to four-family residential real estate loans to government-sponsored enterprises such as Freddie Mac and Fannie Mae and through the Federal Home Loan Bank’s Mortgage Partnership Finance Program. We service all the loans that we sell. We also originate loans above the lending limit for conforming loans, which are referred to as “jumbo loans.” We retain a majority of our jumbo loans in our loan portfolio. Jumbo loans that we originate may be fixed- or adjustable-rate loans and typically have 10 to 30 year terms with maximum loan-to-value ratios of 80%. At June 30, 2026, we had $25.2 million in jumbo loans, which represented 39.6% of our one- to four-family residential real estate loans. Our average loan size for jumbo loans was $1.7 million at June 30, 2026. Virtually all of our one- to four-family residential real estate loans are secured by properties located in Marathon County, Wisconsin.

Our adjustable-rate one- to four-family residential real estate loans carry terms to maturity ranging up to 30 years and generally have fixed rates for initial terms of five years, although we also offer terms of three or seven years. Generally, our adjustable rate one- to four-family residential real estate loans are not adjusted based on an index but are adjusted from time-to-time internally at the discretion of Marathon Bank. The maximum amount by which the initial interest rate may be increased is up to 1.0% per year during the adjustment period, with a lifetime interest rate cap of 15% over the initial interest rate of the loan. We typically hold in our loan portfolio our adjustable-rate one- to four-family residential real estate loans.

We generally limit the loan-to-value ratios of our mortgage loans without private mortgage insurance to 80% of the sales price or appraised value, whichever is lower. Loans where the borrower obtains private mortgage insurance may be made with loan-to-value ratios up to 100%.

We generally do not offer “interest only” mortgage loans on permanent one- to four-family residential real estate loans (where the borrower pays interest for an initial period, after which the loan converts to a fully amortizing loan). We also do not offer loans that provide for negative amortization of principal, such as “Option ARM” loans, where the borrower can pay less than the interest owed on the loan, resulting in an increased principal balance during the life of the loan. We do not have a “subprime lending” program for one- to four-family residential real estate loans (i.e., loans that generally target borrowers with weakened credit histories).

Generally, residential mortgage loans that we originate include “due-on-sale” clauses, which give us the right to declare a loan immediately due and payable in the event that, among other things, the borrower sells or otherwise disposes of the real property subject to the mortgage and the loan is not repaid. All borrowers are required to obtain title

insurance for the benefit of Marathon Bank. We also require homeowner’s insurance and fire and casualty insurance and, where circumstances warrant, flood insurance on properties securing real estate loans.

Commercial and Industrial Loans. At June 30, 2026, we had $2.7 million of commercial and industrial loans, representing 1.3% of our total portfolio. These loans are generally originated to small businesses and medical providers in our primary market areas. Our commercial and industrial loans are generally used by the borrowers for working capital purposes or for acquiring equipment or inventory. To the extent these loans are secured, they are primarily secured by business assets other than real estate, such as business equipment, inventory and accounts receivable. Our commercial and industrial loans are generally lines of credit with terms of one to two years. Our commercial and industrial lines of credit are generally priced on an adjustable-rate basis tied toThe Wall Street Journal Prime Rate. We generally obtain personal guarantees with commercial and industrial loans.

At June 30, 2026, the average loan size of our commercial and industrial loans was $60,000, and our largest outstanding commercial and industrial loan balance was a $378,000 loan to a trucking company. This loan was performing in accordance with its repayment terms at June 30, 2026.

When making commercial and industrial loans, we consider the financial statements of the borrower, our lending history with the borrower, the debt service capabilities of the borrower, the projected cash flows of the business and the value of the collateral, accounts receivable, inventory and equipment. Depending on the collateral used to secure the loans, commercial and industrial loans are made in amounts generally of up to 75% of the value of the collateral securing the loan. At June 30, 2026, $1.4 million of commercial and industrial loans were unsecured.

Construction Loans. At June 30, 2026, construction loans totaled $137,000, or 0.1% of our total loan portfolio. We have $13,000 in undrawn amounts on construction loans at June 30, 2026. These loans are with local developers for the construction of one-to four-family residential real estate developments and are secured by properties located in our primary market areas. Because our construction loan originations are with select customers, the terms of our construction loan originations are not based on standardized terms and instead are individually negotiated.

Consumer Lending. To a much lesser extent, we offer a variety of consumer loans to individuals who reside or work in our market area, including home equity lines of credit, new and used automobile loans, and loans secured by certificates of deposit. At June 30, 2026, our consumer loan portfolio totaled $3.0 million, or 1.4% of our total loan portfolio. At June 30, 2026, we had $10,700 in unsecured consumer loans.

At June 30, 2026, home equity lines of credit (which we categorize as consumer loans) totaled $2.7 million in outstanding balances. The underwriting standards utilized for home equity lines of credit include a determination of the applicant’s credit history, an assessment of the applicant’s ability to meet existing obligations and payments on the proposed loan and the value of the collateral securing the loan. Home equity lines of credit are offered with an aggregate loan-to-value ratio up to 80%. Our home equity lines of credit are generally 10-year balloon loans. Our home equity lines of credit have adjustable rates of interest which are indexed to the Prime Rate, as reported inThe Wall Street Journal.

Loan Underwriting Risks

Commercial Real Estate and Multifamily Real Estate Loans. Loans secured by commercial and multifamily real estate generally have larger balances and involve a greater degree of risk than one- to four-family residential real estate loans. The primary concerns in commercial and multifamily real estate lending are the borrower’s creditworthiness and the feasibility and cash flow potential of the project. Payments on loans secured by income properties often depend on successful operation and management of the properties. As a result, repayment of such loans may be subject, to a greater extent than residential real estate loans, to adverse conditions in the real estate market or the economy. Continued uncertainty or weakness in economic conditions may impair a borrower’s business operations and lead to existing lease turnover. Vacancy rates for retail, office and industrial space may increase which could result in rents falling. The combination of these factors could result in deterioration in the fundamentals underlying the commercial real estate market and the deterioration in value of some of our loans, especially in industries that have been particularly adversely impacted by long-term work-from-home arrangements, including retail stores, hotels and office

buildings, for example. To monitor cash flows on income properties, we require borrowers and loan guarantors to provide annual financial statements on commercial real estate loans. In reaching a decision on whether to make a commercial or multifamily real estate loan, we consider and review a global cash flow analysis of the borrower and consider the net operating income of the property, the borrower’s expertise, credit history and profitability, and the value of the underlying property. A Phase I environmental site assessment is obtained when the possibility exists that hazardous materials may have existed on the site, or the site may have been impacted by adjoining properties that handled hazardous materials.

If we foreclose on a commercial or multifamily real estate loan, the marketing and liquidation period to convert the real estate asset to cash can be lengthy with substantial holding costs. In addition, vacancies, deferred maintenance, repairs and market stigma can result in prospective buyers expecting sale price concessions to offset their real or perceived economic losses for the time it takes them to return the property to profitability. Depending on the individual circumstances, initial charge-offs and subsequent losses on commercial and multifamily real estate loans can be unpredictable and substantial.

One- to Four-Family Non-Owner Occupied Residential Real Estate Loans. One- to four-family non-owner occupied residential real estate loans are subject to some of the same risks as our commercial real estate and multifamily real estate loans, in that they depend on the borrower’s creditworthiness and the feasibility and cash flow potential of the project. Such loans are also subject to similar risks with respect to foreclosures and subsequent operations of the property and resale.

Construction, Land and Development Loans. Our construction loans are based upon estimates of costs and values associated with the completed project. Underwriting is focused on the borrowers’ financial strength, credit history and demonstrated ability to produce a quality product and effectively market and manage their operations.

Construction lending involves additional risks when compared with permanent lending because funds are advanced upon the security of the project, which is of uncertain value prior to its completion. Because of the uncertainties inherent in estimating construction costs, as well as the market value of the completed project and the effects of governmental regulation of real property, it is relatively difficult to evaluate accurately the total funds required to complete a project and the related loan-to-value ratio. In addition, generally during the term of a construction loan, interest may be funded by the borrower or disbursed from an interest reserve set aside from the construction loan budget. These loans often involve the disbursement of substantial funds with repayment primarily dependent on the success of the ultimate project and the ability of the borrower to sell or lease the property or obtain permanent take-out financing, rather than the ability of the borrower or guarantor to repay principal and interest. If the appraised value of a completed project proves to be overstated, we may have inadequate security for the repayment of the loan upon completion of construction of the project and may incur a loss.

Commercial and Industrial Loans. Commercial and industrial loans generally have greater credit risk than residential real estate loans. Unlike residential real estate loans, which generally are made on the basis of the borrower’s ability to make repayment from his or her employment or other income, and which are secured by real property whose value tends to be more easily ascertainable, commercial and industrial loans generally are made on the basis of the borrower’s ability to repay the loan from the cash flow of the borrower’s business. As a result, the availability of funds for the repayment of commercial and industrial loans may depend substantially on the success of the business itself. Further, any collateral securing the loans may depreciate over time, may be difficult to appraise and may fluctuate in value. We try to minimize these risks through our underwriting standards.

Consumer Loans. Consumer loans other than home equity loans generally have greater risk compared to longer-term loans secured by improved, owner-occupied real estate, particularly consumer loans that are secured by rapidly depreciable assets, such as automobiles. In these cases, any repossessed collateral for a defaulted loan may not provide an adequate source of repayment of the outstanding loan balance. As a result, consumer loan collections are primarily dependent on the borrower’s continuing financial stability and thus are more likely to be adversely affected by job loss, divorce, illness or personal bankruptcy.

Balloon Loans. Although balloon mortgage loans may reduce to an extent our vulnerability to changes in market interest rates because they may re-price at the end of the term, subject to renegotiation of rate and terms at maturity, the ability of the borrower to renew or repay the loan and the marketability of the underlying collateral may be adversely affected if real estate values decline prior to the expiration of the term of the loan or in a rising interest rate environment.

Adjustable-Rate Loans. Although adjustable-rate mortgage loans may reduce to an extent our vulnerability to changes in market interest rates because they periodically re-price, as interest rates increase the required payments due from the borrower also increase (subject to rate caps), increasing the potential for default by the borrower. At the same time, the ability of the borrower to repay the loan and the marketability of the underlying collateral may be adversely affected by higher interest rates. Upward adjustments of the contractual interest rate are also limited by our maximum periodic and lifetime rate adjustments. Moreover, the interest rates on most of our adjustable-rate loans do not adjust for up to five years after origination. As a result, the effectiveness of adjustable-rate mortgage loans in compensating for changes in general interest rates may be limited during periods of rapidly rising interest rates.

Originations, Purchases and Sales of Loans

Residential lending activities are conducted by salaried and commissioned loan personnel operating at our main and branch office locations. Loans we originate are underwritten pursuant to our policies and procedures. Loans originated with the intent for sale are also underwritten pursuant to secondary market guidelines. Our ability to originate fixed-rate loans, adjustable-rate loans or balloon loans depends on relative customer demand for such loans, which can be affected by current and expected future levels of market interest rates. We originate residential real estate loans through our loan originators, marketing efforts, our customer base, walk-in customers and referrals from real estate brokers, builders, accountants and financial advisors.

Commercial lending activities are conducted by salaried commercial lenders operating primarily out of our main location. All loans originated by us are underwritten pursuant to our policies and procedures. Our commercial loans are typically fixed-rate balloon loans with terms of typically five years, with loan rates dependent on current and expected future levels of market interest rates. Commercial and multifamily lending are sourced primarily through loan originator contacts, networking and marketing efforts, our customer base and referrals from real estate brokers, accountants and financial advisors.

We currently sell a significant majority of the conforming fixed-rate one- to four-family residential real estate loans we originate on the secondary market. We typically sell our conforming fixed-rate one- to four-family residential real estate loans to Fannie Mae, Freddie Mac and through the Federal Home Loan Bank’s Mortgage Partnership Finance Program. We service all the loans that we sell. During the year ended June 30, 2026, we originated $5.0 million of one- to four-family residential real estate loans and sold $5.1 million, and during the year ended June 30, 2025, we originated $5.9 million of one- to four-family residential real estate loans and sold $6.1 million. We recognize, at the time of sale, the cash gain or loss on the sale of the loans based on the difference between the net cash proceeds received and the carrying value of the loans sold.

We purchase loan participations secured by properties primarily in the state of Wisconsin in loans in which we are not the lead lender. In these circumstances, we follow our customary loan underwriting and approval policies. At June 30, 2026, the outstanding balances of our loan participations where we are not the lead lender totaled $7.7 million, or 3.5% of our loan portfolio, of which $1.7 million were commercial real estate loans and $6.0 million were multifamily real estate loans. All such loans were performing in accordance with their original repayment terms. We also have participated out portions of loans that exceeded our loans-to-one borrower legal lending limit and for risk diversification. At June 30, 2026, we had participated out portions of three loans with an aggregate amount of $7.5 million. Historically, we have not purchased whole loans.

Loan Approval Procedures and Authority

Pursuant to applicable law, the aggregate amount of loans that we are permitted to make to any one borrower or a group of related borrowers is generally limited to 20% of our capital, subject to certain exceptions. At June 30, 2026,

based on the 20% limitation, our loans-to-one-borrower limit was approximately $7.8 million. At June 30, 2026, our largest loan relationship with one borrower was for $6.4 million, which was secured by commercial real estate properties, with the underlying loans performing in accordance with their original terms on that date.

Our lending is subject to written underwriting standards and origination procedures. Decisions on loan applications are made on the basis of detailed applications submitted by the prospective borrower, credit histories that we obtain, and property valuations (consistent with our appraisal policy) prepared by outside independent licensed appraisers approved by our board of directors as well as internal evaluations, where permitted by regulations. The loan applications are designed primarily to determine the borrower’s ability to repay the requested loan, and the more significant items on the application are verified through use of credit reports, bank statements and tax returns.

All loan approval amounts are based on the aggregate loans, including total balances of outstanding loans and the proposed loan to the individual borrower and any related entity. Our president and chief executive officer has individual authorization to approve loans up to $500,000. Our chief credit officer has individual authorization to approve loans up to $100,000. Our Loan Committee, which consists of at least two board members and our chief executive officer and chief credit officer can approve loans up to $1.0 million in the aggregate. Loans in excess of $1.0 million require the approval of our full board of directors.

Delinquencies and Asset Quality

Delinquency Procedures. When a loan payment becomes 10 days past due, we contact the customer by mailing a late notice, and loan officers may contact their customers. If a loan payment becomes 45 days past due, we mail an additional late notice and a loan-specific letter written by a collection representative, and we also place telephone calls to the borrower. These loan collection efforts continue until a loan becomes 90 days past due, at which point we would refer the loan for foreclosure proceedings unless management determines that it is in the best interest of Marathon Bank to work further with the borrower to arrange a workout plan. The foreclosure process would begin when a loan becomes 120 days delinquent. From time to time we may accept deeds in lieu of foreclosure.

Loans Past Due and Non-Performing Assets. Loans are reviewed on a regular basis. Loans that do not share common risk characteristics with other loans are evaluated individually and are not included in the collective analysis. The allowance for credit losses on loans that are individually evaluated may be estimated based on their expected cash flows, or, in the case of loans for which repayment is expected substantially through the operation or sale of collateral when the borrower is experiencing financial difficulty, may be measured based on the fair value of the collateral less estimated costs to sell. Non-accrual loans are loans for which collectability is questionable and, therefore, interest on such loans will no longer be recognized on an accrual basis. All loans that become 90 days or more delinquent are placed on non-accrual status unless the loan is well secured and in the process of collection. When loans are placed on non-accrual status, unpaid accrued interest is fully reversed, and further income is recognized only to the extent received on a cash basis or cost recovery method.

When we acquire real estate as a result of foreclosure, the real estate is classified as foreclosed assets. Assets acquired through, or in lieu of, loan foreclosure are held for sale and are initially recorded at fair value less estimated cost to sell at the date of foreclosure, establishing a new cost basis. Subsequent to foreclosure, valuations are periodically performed by management and the assets are carried at the lower of carrying amount or fair value less cost to sell. Revenue and expenses from operations and changes in the valuation allowance are included in net expenses from foreclosed assets.

Delinquent Loans**.** The following table sets forth our loan delinquencies, including non-accrual loans, by type and amount at the dates indicated.

Non-Performing Assets. The following table sets forth information regarding our non-performing assets. Non-performing assets include other real estate owned of $996,000 related to the foreclosure of collateral supporting a construction loan which was valued at $996,000 based on an offer to sell the property accepted by the Company in August 2025. The sale contract was terminated during the three months ended December 31, 2025 and the Company has relisted the property for $1.5 million. Non-performing loans at June 30, 2026 and 2025 consisted of one one-to four-family residential loan that was fully secured.

During the fiscal year ended June 30, 2023, the Company foreclosed on collateral supporting a construction loan which was valued at $2.3 million and was included in foreclosed assets (OREO), net. The valuation was based on independent appraisals subject to certain discounts less estimated costs to sell. A subsequent independent appraisal was obtained in April 2024 subject to certain discounts less estimated costs to sell. After adjusting for estimated costs to sell, the revised valuation was $1.4 million resulting in a provision for valuation allowance of $937,100 being recorded during the year ended June 30, 2024. An offer to sell the property for $1.1 million was accepted by the Company in August 2025 resulting in a provision for valuation allowance of $378,767 being recorded during the year ended June 30, 2025. The sale contract was terminated during the three months ended December 31, 2025 and the Company has relisted the property for $1.5 million. The recorded investment in one-to-four-family owner occupied properties that were in the process of foreclosure was approximately $66,000 and $67,000 at June 30, 2026 and 2025, respectively.

Classified Assets**.** Federal regulations provide for the classification of loans and other assets, such as debt and equity securities considered to be of lesser quality, as “substandard,” “doubtful” or “loss.” An asset is considered “substandard” if it is inadequately protected by the current net worth and paying capacity of the obligor or of the collateral pledged, if any. “Substandard” assets include those characterized by the “distinct possibility” that the insured institution will sustain “some loss” if the deficiencies are not corrected. Assets classified as “doubtful” have all of the weaknesses inherent in those classified “substandard,” with the added characteristic that the weaknesses present make “collection or liquidation in full,” on the basis of currently existing facts, conditions, and values, “highly questionable and improbable.” Assets classified as “loss” are those considered “uncollectible” and of such little value that their continuance as assets without the establishment of a specific loss allowance is not warranted. Assets which do not

currently expose the insured institution to sufficient risk to warrant classification in one of the aforementioned categories but possess weaknesses are designated as “special mention” or “Watch” by our management.

On the basis of our review of our loans, our classified and special mention or watch loans at the dates indicated were as follows. At June 30, 2026, one commercial real estate loan totaling $648,000 was rated special mention/watch. At June 30, 2025, special mention/watch rated loans consisted of one commercial real estate loan of $657,000 and one multifamily real estate loan of $494,000 from one customer relationship.

Allowance for Credit Losses

Allowance for Credit Losses on Loans. The allowance for credit losses on loans is established through charges to earnings in the form of a provision for credit losses. Loan losses are charged against the allowance for credit losses for the difference between the carrying value of the loan and the estimated net realizable value or fair value of the collateral, if collateral dependent, when management believes that the collectability of the principal is unlikely. Subsequent recoveries, if any, are credited to the allowance.

The allowance represents management’s current estimate of expected credit losses over the contractual term of loans, and is recorded at an amount that, in management’s judgment, reduces the recorded investment in loans to the net amount expected to be collected. No allowance for credit loss is recorded on accrued interest receivable and amounts written-off are reversed by an adjustment to interest income. Management’s judgment in determining the level of the allowance is based on evaluations of historical loan losses, current conditions and reasonable and supportable forecasts relevant to the collectability of loans. Loans that share common risk characteristics are evaluated collectively using a weighted-average remaining maturity methodology. The weighted-average remaining maturity methodology uses an average annual charge-off rate as a foundation for estimating the credit loss for the remaining balances of all loan pools. The average annual charge-off rate is applied to the contractual term, further adjusted for estimated prepayments to determine the unadjusted historical charge-off rate.

Management’s estimate of the allowance for credit losses on loans that are collectively evaluated also includes a qualitative assessment of available information relevant to assessing collectability that is not captured in the loss estimation process. This includes forecasts that are reasonable and supportable concerning expectations of future economic conditions. The reasonable and supportable forecast period is 24 months. This evaluation is inherently subjective, as it requires estimates that are susceptible to significant revision as more information becomes available.

Each factor is assigned a value to reflect improving, stable or declining conditions based on management’s best judgment using relevant information available at the time of the evaluation. Adjustments to the factors are supported through documentation of changes in conditions in a narrative accompanying the allowance for credit losses calculation for our loan portfolio.

Loans that do not share common risk characteristics with other loans are evaluated individually and are not included in the collective analysis. The allowance for credit losses on loans that are individually evaluated may be estimated based on their expected cash flows, or, in the case of loans for which repayment is expected substantially through the operation or sale of collateral when the borrower is experiencing financial difficulty, may be measured based on the fair value of the collateral less estimated costs to sell. In addition, the WDFI and the FDIC periodically review our

allowance for credit losses and as a result of such reviews, we may have to adjust our allowance for loan losses or recognize further loan charge-offs.

Allowance for Credit Losses on Unfunded Commitments. The Company records an allowance, reported in other liabilities, for expected credit losses on commitments to extend credit that are not unconditionally cancelable by the Company. The allowance for unfunded commitments is measured based on the principles utilized in estimating the allowance for credit losses on loans and an estimate of the amount of unfunded commitments expected to be advanced. Changes in the allowance for unfunded commitments are recorded through the provision for credit losses.

Allowance for Credit Losses on Available for Sale (“AFS”) Securities.* *The ASC 326 standard requires credit losses to be presented as an allowance for credit losses (“ACL”). The Company is still required to conduct an impairment evaluation on AFS securities to determine whether the Company has the intent to sell the security or it is more likely than not that it will be required to sell the security before recovery. If these situations apply, the guidance continues to require the Company to reduce the security's amortized cost basis down to its fair value through earnings. The Company also evaluates the unrealized losses on AFS securities to determine if a security's decline in fair value below its amortized cost basis is due to credit factors. The evaluation is based upon factors such as the creditworthiness of the underlying borrowers, performance of the underlying collateral, if applicable, and the level of credit support in the security structure. Management also evaluates other factors and circumstances that may be indicative of a decline in the fair value of the security due to a credit factor. This includes, but is not limited to, the extent to which fair value is less than amortized cost, the current interest rate environment, changes to rating of security or security issuer, and adverse conditions specifically related to the security among other factors. If this assessment indicates that a credit loss exists, the present value of the expected cash flows of the security is compared to the amortized cost basis of the security. If the present value of the cash flows expected to be collected is less than the amortized cost, an ACL is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis under the Current and Expected Credit Loss (“CECL”) standard, and declines due to non-credit factors are recorded in accumulated other comprehensive income (“AOCI”), net of taxes. If a credit loss is recognized in earnings, subsequent improvements to the expectation of collectability will be recognized through the ACL. If the fair value of the security increases above its amortized cost, the unrealized gain will be recorded in AOCI, net of taxes, on the consolidated balance sheets. Accrued interest receivable on AFS securities is excluded from the estimate of credit losses.

Allowance for Credit Losses on Held to Maturity (“HTM”) Securities. The Company’s portfolio of held to maturity securities consists of U.S. agency residential mortgage-backed securities which are highly rated by major rating agencies and have a long history of no credit losses. In estimating the net amount expected to be collected for held to maturity securities in an unrealized loss position, a historical loss based method is utilized.

The following table sets forth activity in our allowance for credit losses for the years indicated.

Allocation of Allowance for Credit Losses. The following table sets forth the allowance for loan losses allocated by loan category and the percent of the allowance in each category to the total allocated allowance at the dates indicated. The allowance for loan losses allocated to each category is not necessarily indicative of future losses in any particular category and does not restrict the use of the allowance to absorb losses in other categories.

Investment Activities

General. Our board of directors is responsible for approving and overseeing our investment policy. The investment policy is reviewed at least annually by management and any changes to the policy are recommended to the board of directors and are subject to its approval. This policy dictates that investment decisions be made based on the safety of the investment, regulatory standards, liquidity requirements, potential returns and consistency with our interest rate risk management strategy. Our investment/asset liability management committee, which consists of our President and Chief Executive Officer, Chief Financial Officer, Chief Administrative Officer and Chief Credit Officer and the board of directors, oversees our investing activities and strategies. All transactions are formally reviewed by the board of directors at least monthly.

Our current investment policy authorizes us to invest in debt securities issued by the U.S. government and its agencies or government sponsored enterprises. The policy also permits investments in mortgage-backed securities, including pass-through securities, issued and guaranteed by Fannie Mae, Freddie Mac and Ginnie Mae, as well as investments in federal funds and deposits in other insured institutions. In addition, management is authorized to invest in investment grade state and municipal obligations and corporate debt obligations within regulatory parameters. We do not engage in any investment hedging activities or trading activities, nor do we purchase any high-risk mortgage derivative products, corporate junk bonds, and certain types of structured notes.

Debt and equity securities investment accounting guidance requires that, at the time of purchase, we designate a security as held to maturity, available for sale, or trading, depending on our ability and intent. At all dates below, we had a portfolio of debt securities held to maturity at amortized cost and a portfolio of debt securities available for sale which is reported at fair value.

Corporate Debt Securities. At June 30, 2026, we had corporate debt securities totaling $3.0 million, which constituted 68.0% of our securities portfolio. All of our corporate debt securities are investment grade and have maturities not in excess of ten years. These securities generally provide slightly higher yields than U.S. government and agency securities and mortgage-backed securities.

State and Political Subdivision (“Municipal”) Securities. At June 30, 2026, we had municipal securities totaling $380,000, which constituted 8.7% of our securities portfolio. These securities often provide slightly higher after-tax yields than U.S. government and agency securities and mortgage-backed securities, but are not as liquid as other

investments, so we typically maintain investments in municipal securities, to the extent appropriate, for generating returns in our investment portfolio.

Mortgage-Backed Securities. At June 30, 2026, we had mortgage-backed securities totaling $1.0 million, which constituted 23.3% of our securities portfolio, including $677,000 of agency collateralized mortgage obligations (CMOs). Of the $342,000 of non-CMO mortgage-backed securities, $17,000 were commercial-backed and $325,000 were residential mortgage-backed securities. Mortgage-backed securities are securities issued in the secondary market that are collateralized by pools of mortgages. Certain types of mortgage-backed securities are commonly referred to as “pass-through” certificates because the principal and interest of the underlying loans is “passed through” to investors, net of certain costs, including servicing and guarantee fees. Residential mortgage-backed securities typically are collateralized by pools of one- to four-family or multifamily mortgages, although we invest primarily in mortgage-backed securities backed by one- to four-family mortgages. Commercial mortgage-backed securities typically are collateralized by pools of commercial mortgage loans. The issuers of such securities pool and resell the participation interests in the form of securities to investors such as Marathon Bank. The interest rate of the security is lower than the interest rates of the underlying loans to allow for payment of servicing and guaranty fees. All of our mortgage-backed securities are either backed by Ginnie Mae, a U.S. government agency, the Small Business Administration or government-sponsored enterprises, such as Fannie Mae and Freddie Mac.

Residential and commercial mortgage-backed securities issued by U.S. government agencies and government-sponsored enterprises are more liquid than individual mortgage loans because there is an active trading market for such securities. In addition, residential and commercial mortgage-backed securities may be used to collateralize our borrowings. Investments in residential and commercial mortgage-backed securities involve a risk that actual payments will be greater or less than the prepayment rate estimated at the time of purchase, which may require adjustments to the amortization of any premium or accretion of any discount relating to such interests, thereby affecting the net yield on our securities. Current prepayment speeds determine whether prepayment estimates require modification that could cause amortization or accretion adjustments.

Other Securities. We held common stock of the Federal Home Loan Bank of Chicago in connection with our borrowing activities totaling $1.5 million and $1.3 million, respectively, at June 30, 2026 and 2025. The Federal Home Loan Bank of Chicago common stock is carried at cost. We may be required to purchase additional Federal Home Loan Bank of Chicago stock if we increase borrowings in the future.

Portfolio Maturities and Yields. The composition and maturities of the debt securities held to maturity portfolio at June 30, 2026, are summarized in the following table. Maturities are based on the final contractual payment dates, and do not reflect the effect of scheduled principal repayments, prepayments, or early redemptions that may occur. All of our debt securities in this table at June 30, 2026, were taxable securities. Please refer to Note 3 of the notes to the audited consolidated financial statements for the composition and maturities of the debt securities available for sale portfolio at June 30, 2026.

Sources of Funds

General. Deposits have traditionally been our primary source of funds for use in lending and investment activities. We also use borrowings to supplement cash flow needs, lengthen the maturities of liabilities for interest rate risk purposes and to manage the cost of funds, and have increased our use of borrowings in recent periods. In addition, we receive funds from scheduled loan payments, investment maturities, loan prepayments, retained earnings and income on earning assets. While scheduled loan payments and income on earning assets are relatively stable sources of funds,

deposit inflows and outflows can vary widely and are influenced by prevailing interest rates, market conditions and levels of competition.

Deposits. Our deposits are generated primarily from residents within our primary market area. We offer a selection of deposit accounts, including non-interest-bearing checking accounts, interest-bearing checking accounts, money market accounts, savings accounts and certificates of deposit. Deposit account terms vary, with the principal differences being the minimum balance required, the amount of time the funds must remain on deposit and the interest rate. At June 30, 2026, we had $14.0 million in brokered deposits. At June 30, 2026, our core deposits, which are deposits other than certificates of deposit, were $114.9 million, representing 60.1% of total deposits.

Interest rates, maturity terms, service fees and withdrawal penalties are established on a periodic basis. Deposit rates and terms are based primarily on current operating strategies and market rates, liquidity requirements, rates paid by competitors and growth goals. The flow of deposits is influenced significantly by general economic conditions, changes in interest rates and competition. The variety of deposit accounts that we offer allows us to be competitive in generating deposits and to respond with flexibility to changes in our customers’ demands. Our ability to gather deposits is impacted by the competitive market in which we operate, which includes numerous financial institutions of varying sizes offering a wide range of products. We believe that deposits are a stable source of funds, but our ability to attract and maintain deposits at favorable rates will be affected by market conditions, including competition and prevailing interest rates.

The following table sets forth the distribution of total deposits by account type at the dates indicated.

As of June 30, 2026, the aggregate amount of uninsured deposits (deposits in amounts greater than or equal to $250,000, which is the maximum amount for federal deposit insurance) was $77.3 million, of which $10.0 million was the aggregate amount of our uninsured certificates of deposit. As of June 30, 2025, the aggregate amount of uninsured deposits was $64.9 million, of which $10.8 million was the aggregate amount of our uninsured certificates of deposit. The following table sets forth the maturity of these certificates of deposit as of June 30, 2026.

Borrowings**.** As of June 30, 2026, we had a master contract agreement with the Federal Home Loan Bank of Chicago pursuant to which we could borrow up to $87.0 million subject to providing additional collateral. At June 30, 2026 and 2025, we had $20.0 million and $15.0 million, respectively of Federal Home Loan Bank of Chicago advances (see Note 10 of the Notes to the Audited Consolidated Financial Statements). The Bank also has $19.6 million available to borrow from the Federal Reserve Bank which is pledged by multi-family loans and an unsecured Federal Funds purchasing limit of $5.0 million with the Bank’s correspondent bank. There were no borrowings under these arrangements at June 30, 2026.

Personnel and Human Capital Resources

As of June 30, 2026, we had 31 full-time equivalent employees. Our employees are not represented by any collective bargaining group. Management believes that we have good working relations with our employees. We believe our ability to attract and retain employees is a key to our success. Accordingly, we strive to offer competitive salaries and employee benefits to all employees and monitor salaries in our market areas. In addition, we are committed to developing our staff through continuing education and specialty education within banking, which may include using universities that offer banking management programs, when applicable.

Subsidiary Activities

Marathon Bank is the only subsidiary of Marathon Bancorp. Marathon Bank has two subsidiaries, Marathon Property Holdings, LLC and 520 N 28th Avenue, LLC which both hold bank properties or other real estate owned properties.

TAXATION

Marathon Bank and Marathon Bancorp are subject to federal and state income taxation in the same general manner as other corporations, with some exceptions discussed below. The following discussion of federal and state taxation is intended only to summarize material income tax matters and is not a comprehensive description of the tax rules applicable to Marathon Bancorp and Marathon Bank.

Our federal and state tax returns have not been audited for the past five years.

Federal Taxation

Method of Accounting. For federal income tax purposes, Marathon Bank currently reports its income and expenses on the accrual method of accounting and uses a tax year ending June 30 for filing its federal income tax returns. Marathon Bancorp and Marathon Bank intend to file a consolidated federal income tax return for the taxable year ended June 30, 2026. The Small Business Protection Act of 1996 eliminated the use of the mutual savings bank bad debt reserve method of calculating the tax return bad debt deduction. For taxable years beginning after 1995, Marathon Bank has been subject to the same bad debt reserve rules as commercial banks. It currently utilizes the experience method of deducting bad debts under Section 585 of the Internal Revenue Code.

Net Operating Loss Carryovers. Effective with the passage of the Tax Cuts and Jobs Act, net operating loss carrybacks are no longer permitted, and net operating losses are allowed to be carried forward indefinitely. Net operating loss carryforwards arising from tax years beginning after 2018 are limited to offset a maximum of 80% of a future year’s taxable income. At June 30, 2026, the Company had no federal net operating loss carryforwards.

Capital Loss Carryovers. A corporation cannot recognize capital losses in excess of capital gains generated. Generally, a financial institution may carry back capital losses to the preceding three taxable years and forward to the succeeding five taxable years. Any capital loss carryback or carryover is treated as a short-term capital loss for the year to which it is carried. As such, it is grouped with any other capital losses for the year to which it is carried and is used to offset any capital gains. Any unutilized loss carryforward remaining after the five-year carryover period is not deductible. At June 30, 2026, the Company had no capital loss carryovers.

Corporate Dividends. Marathon Bancorp may generally exclude from its income 100% of dividends received from Marathon Bank as a member of the same affiliated group of corporations.

State Taxation

As a Maryland business corporation, Marathon Bancorp is required to file an annual report with and pay franchise taxes to the state of Maryland.

Marathon Bancorp and Marathon Bank are subject to the Wisconsin corporate franchise (income) tax. The State of Wisconsin imposes a corporate franchise tax of 7.9% on the combined taxable income of the members of a consolidated income tax group.

In general, Wisconsin net business losses may be carried forward to the succeeding 20 taxable years. At June 30, 2026, the Company had $13.4 million in Wisconsin net operating loss carryforwards. Due to a change in Wisconsin tax law that provides for a subtraction from the Bank’s state taxable income for loan and fee interest income from certain commercial and agricultural loans, management determined that the Company was highly unlikely to incur a material Wisconsin tax liability in the foreseeable future, instead generating Wisconsin net operating loss carryforwards that would never be realized; and, accordingly a valuation allowance of $1.0 million was established for these carryforwards at June 30, 2026.

REGULATION AND SUPERVISION

General

As a state savings bank, Marathon Bank is subject to examination, supervision and regulation, primarily by the WDFI and by the FDIC. The state and federal systems of regulation and supervision establish a comprehensive framework of activities in which Marathon Bank may engage and is intended primarily for the protection of depositors and the FDIC’s Deposit Insurance Fund, and not for the protection of stockholders.

Marathon Bank is also regulated to a lesser extent by the Federal Reserve Board. In addition, Marathon Bank is a member of and owns stock in the Federal Home Loan Bank of Chicago, which is one of the 11 regional banks in the Federal Home Loan Bank System.

As a bank holding company, Marathon Bancorp is subject to examination and supervision by, and is required to file certain reports with, the Federal Reserve Board. Marathon Bancorp is subject to the rules and regulations of the SEC under the federal securities laws.

Set forth below are certain material regulatory requirements that are applicable to Marathon Bank and Marathon Bancorp. This description of statutes and regulations is not intended to be a complete description of such statutes and regulations and their effects on Marathon Bank and Marathon Bancorp. Any change in these laws or regulations, whether by Congress or the applicable regulatory agencies, could have a material adverse impact on Marathon Bancorp, Marathon Bank and their operations.

Intrastate and Interstate Merger and Branching Activities

Wisconsin Law and Regulation**.** Any Wisconsin savings bank meeting certain requirements may, upon approval of the WDFI, establish one or more branch offices in the state of Wisconsin and the states of Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Missouri, and Ohio. In addition, upon WDFI approval, a Wisconsin savings bank may establish a branch office in any other state as the result of a merger or consolidation.

Federal Law and Regulation**.** The Interstate Banking Act permits the federal banking agencies to, under certain circumstances, approve merger transactions between banks located in different states, regardless of whether the merger would be prohibited under state law. The Interstate Banking Act, as amended, authorizes de novo branching into another state at locations at which banks chartered by the host state could establish a branch. Mergers and the establishment of branches require the prior approval of the FDIC.

Loans and Investments

Wisconsin Law and Regulation.* *Under Wisconsin law and regulation, Marathon Bank is authorized to make, invest in, sell, purchase, participate or otherwise deal in mortgage loans or interests in mortgage loans without geographic restriction, including loans made on the security of residential and commercial property. Wisconsin savings banks also may lend funds on a secured or unsecured basis for business, commercial or agricultural purposes, provided

the total of all such loans does not exceed 20% of the savings bank’s total assets, unless the WDFI authorizes a greater amount. Loans are subject to certain other limitations, including percentage restrictions based on total assets.

Wisconsin savings banks may invest funds in certain types of debt and equity securities, including obligations of federal, state and local governments and agencies. Subject to prior approval of the WDFI, compliance with capital requirements and certain other restrictions, Wisconsin savings banks may invest in residential housing development projects. Wisconsin savings banks may also invest in service corporations or subsidiaries with the prior approval of the WDFI, subject to certain restrictions.

Wisconsin savings banks may make loans and extensions of credit, both direct and indirect, to one borrower in amounts up to 20% of the savings bank’s capital plus an additional 5% for loans fully secured by readily marketable collateral. In addition, and notwithstanding the 20% of capital and additional 5% of capital limitations set forth above, Wisconsin savings banks may make loans to one borrower, or a related group of borrowers, for any purpose in an amount not to exceed $500,000, or to develop domestic residential housing units in an amount not to exceed the lesser of $30 million or 30% of the savings bank’s capital, subject to certain conditions. This limit may be increased to 50% of capital for loans secured by certain assets. At June 30, 2026, Marathon Bank did not have any loans which exceeded the “loans-to-one borrower” limitations.

Federal Law and Regulation**.** FDIC regulations also govern the equity investments of Marathon Bank and, notwithstanding Wisconsin law and regulations, such regulations prohibit Marathon Bank from making certain equity investments and generally limit Marathon Bank’s equity investments to those that are permissible for national banks and their subsidiaries. Also, under FDIC regulations, Marathon Bank must obtain prior FDIC approval before directly, or indirectly through a majority-owned subsidiary, engaging “as principal” in any activity that is not permissible for a national bank unless certain exceptions apply. The activity regulations provide that state banks that meet applicable minimum capital requirements and other specified criteria would be permitted to engage in certain activities that are not permissible for national banks, including certain real estate and securities activities conducted through subsidiaries. The FDIC will not approve an activity that it determines presents a significant risk to the FDIC insurance fund. The current activities of Marathon Bank and its subsidiaries are permissible under applicable federal regulations.

Lending Standards

Wisconsin Law and Regulation.* *Wisconsin law and regulations issued by the WDFI impose on Wisconsin savings banks certain fairness in lending requirements and prohibit savings banks from discriminating against a loan applicant based upon the applicant’s physical condition, developmental disability, sex, marital status, race, color, creed, national origin, religion or ancestry.

Federal Law and Regulation**.** The federal banking agencies have adopted uniform regulations prescribing standards for extensions of credit that are secured by liens on interests in real estate or made for the purpose of financing the construction of a building or other improvements to real estate. Under the joint regulations adopted by the federal banking agencies, all insured depository institutions, such as Marathon Bank, must adopt and maintain written policies that establish appropriate limits and standards for extensions of credit that are secured by liens or interests in real estate or are made for the purpose of financing permanent improvements to real estate. These policies must establish loan portfolio diversification standards, prudent underwriting standards (including loan-to-value limits) that are clear and measurable, loan administration procedures, and loan documentation, approval and reporting requirements. The real estate lending policies must reflect consideration of the Interagency Guidelines for Real Estate Lending Policies (the “Interagency Guidelines”) that have been adopted by the federal bank regulators.

The Interagency Guidelines, among other things, require a depository institution to establish internal loan-to-value limits for real estate loans that are not in excess of the following supervisory limits:

Although no supervisory loan-to-value limit has been established for permanent mortgages on owner-occupied, one- to four-family or home equity loans, the Interagency Guidelines state that for any such loan with a loan-to-value ratio that equals or exceeds 90% at origination, an institution should require appropriate credit enhancement in the form of either mortgage insurance or readily marketable collateral.

Deposits

Wisconsin Law and Regulation.* *Under Wisconsin law, Marathon Bank is permitted to establish deposit accounts and accept deposits. Marathon Bank’s board of directors, or its designee, determines the rate and amount of interest to be paid on or credited to deposit accounts subject to FDIC limitations.

Deposit Insurance

Wisconsin Law and Regulation.* *Under Wisconsin law, Marathon Bank is required to obtain and maintain insurance on its deposits from a deposit insurance corporation. The deposits of Marathon Bank are insured up to the applicable limits by the FDIC.

Federal Law and Regulation.* *Marathon Bank is a member of the Deposit Insurance Fund, which is administered by the FDIC. Marathon Bank’s deposit accounts are insured by the FDIC, generally up to a maximum of $250,000 per depositor.

The FDIC imposes deposit insurance assessments against all insured depository institutions. An institution’s assessment rate depends upon the perceived risk of the institution to the Deposit Insurance Fund, with institutions deemed less risky paying lower rates. Currently, assessments for institutions of less than $10 billion of total assets are based on financial measures and supervisory ratings derived from statistical models estimating the probability of failure within three years. Effective January 1, 2023, assessment rates (inclusive of possible adjustments) for institutions of Marathon Bank’s size range from 3.5 to 32 basis points of each institution’s total assets less tangible capital. The FDIC may increase or decrease the range of assessments uniformly, except that no adjustment can deviate more than two basis points from the base assessment rate without notice and comment rulemaking. The FDIC also has the authority to issue special assessments. A significant increase in insurance premiums would have an adverse effect on the operating expenses and results of operations of Marathon Bank. We cannot predict what deposit insurance assessment rates will be in the future.

Insurance of deposits may be terminated by the FDIC upon a finding that an institution has engaged in unsafe or unsound practices, is in an unsafe or unsound condition to continue operations or has violated any applicable law, regulation, rule, order or condition imposed by the FDIC. We do not know of any practice, condition or violation that might lead to termination of deposit insurance at Marathon Bank.

Capital Requirements

Wisconsin Law and Regulation**.** Wisconsin savings banks are required to maintain a minimum net worth ratio of 6% and must maintain total capital necessary to ensure the continuation of insurance of deposit accounts by the FDIC. If the WDFI determines that the financial condition, history, management or earning prospects of a savings bank are not adequate, the WDFI may require a higher minimum capital level for the savings bank. If a Wisconsin savings bank’s capital ratio falls below the required level, the WDFI may direct the savings bank to adhere to a specific written plan established by the WDFI to correct the savings bank’s capital deficiency, as well as a number of other restrictions on the

savings bank’s operations, including a prohibition on the payment of dividends. At June 30, 2026 and June 30, 2025, Marathon Bank’s net worth ratio, as calculated under Wisconsin law, was 15.45% and 15.86%, respectively.

Federal Law and Regulation**.** Federal regulations require FDIC insured depository institutions to meet several minimum capital standards: a common equity Tier 1 capital to risk-based assets ratio of 4.5%, a Tier 1 capital to risk-based assets ratio of 6.0%, a total capital to risk-based assets of 8.0%, and a 4.0% Tier 1 capital to total assets leverage ratio.

Common equity Tier 1 capital is generally defined as common stockholders’ equity and retained earnings. Tier 1 capital is generally defined as common equity Tier 1 and additional Tier 1 capital. Additional Tier 1 capital includes certain noncumulative perpetual preferred stock and related surplus and minority interests in equity accounts of consolidated subsidiaries. Total capital includes Tier 1 capital (common equity Tier 1 capital plus additional Tier 1 capital) and Tier 2 capital. Tier 2 capital is comprised of capital instruments and related surplus, meeting specified requirements, and may include cumulative preferred stock and long-term perpetual preferred stock, mandatory convertible securities, intermediate preferred stock and subordinated debt. Also included in Tier 2 capital is the allowance for loan and lease losses limited to a maximum of 1.25% of risk-weighted assets and, for institutions that have exercised an opt-out election regarding the treatment of AOCI, up to 45% of net unrealized gains on available-for-sale equity securities with readily determinable fair market values. Institutions that have not exercised the AOCI opt-out have AOCI incorporated into common equity Tier 1 capital (including unrealized gains and losses on available-for-sale-securities). Marathon Bank exercised its AOCI opt-out election. Calculation of all types of regulatory capital is subject to deductions and adjustments specified in the regulations.

In determining the amount of risk-weighted assets for purposes of calculating risk-based capital ratios, all assets, including certain off-balance sheet assets (e.g., recourse obligations, direct credit substitutes, residual interests) are multiplied by a risk weight factor assigned by the regulations based on the risks believed inherent in the type of asset. Higher levels of capital are required for asset categories believed to present greater risk. For example, a risk weight of 0% is assigned to cash and U.S. government securities, a risk weight of 50% is generally assigned to prudently underwritten first lien one- to four-family residential real estate loans, a risk weight of 100% is assigned to commercial and consumer loans, a risk weight of 150% is assigned to certain past due loans and a risk weight of between 0% to 600% is assigned to permissible equity interests, depending on certain specified factors.

In addition to establishing the minimum regulatory capital requirements, the regulations limit capital distributions and certain discretionary bonus payments to management if the institution does not hold a “capital conservation buffer” consisting of 2.5% of common equity Tier 1 capital to risk-weighted asset above the amount necessary to meet its minimum risk-based capital requirements.

In assessing an institution’s capital adequacy, the FDIC takes into consideration, not only these numeric factors, but qualitative factors as well, including the bank’s exposure to interest rate risk. The FDIC has the authority to establish higher capital requirements for individual institutions where deemed necessary due to a determination that an institution’s capital level is, or is likely to become, inadequate in light of particular circumstances. Marathon Bank exceeds all regulatory capital requirements and is deemed “well capitalized” for regulatory capital purposes as of June 30, 2026.

Depository institutions and their holding companies that have less than $10 billion in total consolidated assets and meet other qualifying criteria may elect to use the optional community bank leverage ratio framework, which requires maintaining a leverage ratio of greater than 8.0% (reduced from 9% effective July 1, 2026) to satisfy the regulatory capital requirements, including the risk-based requirements. Institutions with capital meeting the specified requirement and electing to follow the alternative framework will be deemed to comply with the applicable regulatory capital requirements, including the risk-based requirements, and are considered well-capitalized under the prompt corrective action framework. Eligible institutions may opt into and out of the community bank leverage ratio framework on their quarterly call report. An institution that temporarily ceases to meet any qualifying criteria is provided with a new four-quarter grace period to again achieve compliance, provided that the institution maintains a leverage ratio greater than 7.0% and has not used the grace period for eight or more quarters in the previous five-year period. Failure to meet

the qualifying criteria within the grace period, maintain a leverage ratio greater than 7.0%, or remain within the grace-period usage limit requires the institution to comply with the generally applicable risk-based capital requirements.

As of June 30, 2026, Marathon Bank elected to use the community bank leverage ratio.

Safety and Soundness Standards

Each federal banking agency, including the FDIC, has adopted guidelines establishing general standards relating to internal controls, internal audit systems, loan documentation, credit underwriting, interest rate exposure, asset growth, asset quality, earnings and compensation, fees and benefits, and information security. In general, the guidelines require, among other things, appropriate systems and practices to identify and manage the risks and exposures specified in the guidelines. The guidelines prohibit excessive compensation as an unsafe and unsound practice and describe compensation as excessive when the amounts paid are unreasonable or disproportionate to the services performed by an executive officer, employee, director, or principal stockholder.

Prompt Corrective Regulatory Action

Federal bank regulatory authorities are required to take “prompt corrective action” with respect to institutions that do not meet minimum capital requirements. For these purposes, the statute establishes five capital categories: well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized, and critically undercapitalized.

Under the regulations, a bank is deemed to be (i) “well capitalized” if it has total risk-based capital of 10.0% or more, has a Tier 1 risk-based capital ratio of 8.0% or more, has a Tier 1 leverage capital ratio of 5.0% or more and a common equity Tier 1 ratio of 6.5% or more, and is not subject to any written capital order or directive; (ii) “adequately capitalized” if it has a total risk-based capital ratio of 8.0% or more, a Tier 1 risk-based capital ratio of 6.0% or more, a Tier 1 leveraged capital ratio of 4.0% or more and a common equity Tier 1 ratio of 4.5% or more, and does not meet the definition of “well capitalized”; (iii) “undercapitalized” if it has a total risk-based capital ratio that is less than 8.0%, a Tier 1 risk-based capital ratio that is less than 6.0%, a Tier 1 leverage capital ratio that is less than 4.0% or a common equity Tier 1 ratio of less than 4.5%; (iv) “significantly undercapitalized” if it has a total risk-based capital ratio that is less than 6.0% and a Tier 1 risk-based capital ratio that is less than 4.0% or a common equity Tier 1 ratio of less than 3.0%; and (v) “critically undercapitalized” if it has a ratio of tangible equity to total assets that is equal to or less than 2.0%.

The previously referenced final rule establishing an elective “community bank leverage ratio” regulatory capital framework provides that a qualifying institution whose capital meets or exceeds the community bank leverage ratio and opts to use that framework will be considered “well capitalized” for purposes of prompt corrective action.

Federal law and regulations also specify circumstances under which a federal banking agency may reclassify a well-capitalized institution as adequately capitalized and may require an institution classified as less than well capitalized to comply with supervisory actions as if it were in the next lower category (except that the FDIC may not reclassify a significantly undercapitalized institution as critically undercapitalized).

The FDIC may order savings banks that have insufficient capital to take corrective actions. For example, a savings bank that is categorized as “undercapitalized” is subject to growth limitations and is required to submit a capital restoration plan, and a holding company that controls such a savings bank is required to guarantee that the savings bank complies with the restoration plan. A “significantly undercapitalized” savings bank may be subject to additional restrictions. Savings banks deemed by the FDIC to be “critically undercapitalized” would be subject to the appointment of a receiver or conservator.

As noted above, Marathon Bank is considered “well capitalized” for regulatory capital purposes as of June 30, 2026.

Dividends

Under Wisconsin law and applicable regulations, a Wisconsin savings bank that meets its regulatory capital requirements may declare dividends on capital stock based upon net profits, provided that its paid-in surplus equals its capital stock. In addition, prior WDFI approval is required before dividends exceeding 50% of net profits for any calendar year may be declared and before a stock dividend may be declared out of retained earnings.

The FDIC has the authority to prohibit Marathon Bank from paying dividends if, in its opinion, the payment of dividends would constitute an unsafe or unsound practice in light of the financial condition of Marathon Bank. Institutions may not pay dividends if they would be “undercapitalized” following payment of the dividend within the meaning of the prompt corrective action regulations.

Liquidity and Reserves

Wisconsin Law and Regulation.* *Under WDFI regulations, all Wisconsin savings banks are required to maintain a certain amount of their assets as liquid assets, consisting of cash and certain types of investments. The exact amount of assets a savings bank is required to maintain as liquid assets is set by the WDFI, but generally ranges from 4% to 15% of the savings bank’s average daily balance of net withdrawable accounts plus short-term borrowings (the “Required Liquidity Ratio”). At June 30, 2026, Marathon Bank’s Required Liquidity Ratio was 8%, and Marathon Bank was in compliance with this requirement. In addition, 50% of the liquid assets maintained by a Wisconsin savings bank must consist of “primary liquid assets,” which are defined to include securities issued by the U.S. Government, U.S. Government agencies or the state of Wisconsin or a subdivision thereof, and cash. At June 30, 2026, Marathon Bank was in compliance with this requirement.

Federal Law and Regulation**.** The Federal Reserve Board currently has no reserve requirement for Marathon Bank.

Transactions with Affiliates and Insiders

Wisconsin Law and Regulation**.** Under Wisconsin law, a savings bank may not make a loan to a person owning 10% or more of its stock, an affiliated person (including a director, officer, the spouse of either and a member of the immediate family of such person who is living in the same residence), agent, or attorney of the savings bank, either individually or as an agent or partner of another, except as provided under the rules of the WDFI and regulations of the FDIC. In addition, unless the prior approval of the WDFI is obtained, a savings bank may not purchase, lease or acquire a site for an office building or an interest in real estate from an affiliated person, including a stockholder owning more than 10% of its capital stock, or from any firm, corporation, entity or family in which an affiliated person or 10% stockholder has a direct or indirect interest.

Federal Law and Regulation.* *Sections 23A and 23B of the Federal Reserve Act govern transactions between an insured savings bank, such as Marathon Bank, and any of its affiliates, including Marathon Bancorp. The Federal Reserve Board has adopted Regulation W, which comprehensively implements and interprets Sections 23A and 23B, in part by codifying prior Federal Reserve Board interpretations under Sections 23A and 23B.

An affiliate of a savings bank is any company or entity that controls, is controlled by or is under common control with the savings bank. A subsidiary of a savings bank that is not also a depository institution or a “financial subsidiary” under federal law is not treated as an affiliate of the savings bank for the purposes of Sections 23A and 23B; however, the FDIC has the discretion to treat subsidiaries of a savings bank as affiliates on a case-by-case basis. Sections 23A and 23B limit the extent to which a savings bank or its subsidiaries may engage in “covered transactions” with any one affiliate to an amount equal to 10% of the savings bank’s capital stock and surplus, and limit all such transactions with all affiliates to an amount equal to 20% of such capital stock and surplus. The term “covered transaction” includes the making of loans, purchase of assets, issuance of guarantees and other similar types of transactions. Most loans and other extensions of credit by a savings bank to any of its affiliates must be secured by collateral in amounts ranging from 100% to 130% of the loan amounts, depending on the type of collateral. In addition, any affiliate transactions by a

savings bank must be on terms that are substantially the same, or at least as favorable, to the savings bank as those that would be provided to a non-affiliate, and be consistent with safe and sound banking practices.

A savings bank’s loans to its executive officers, directors, any owner of more than 10% of its stock (each, an insider) and any of certain entities affiliated with any such person (an insider’s related interest) are subject to the conditions and limitations imposed by Sections 22(g) and 22(h)of the Federal Reserve Act and the Federal Reserve Board’s Regulation O thereunder, as made applicable to state nonmember banks by Section 18(j)(2) of the Federal Deposit Insurance Act and Section 337.3 of the FDIC Rules and Regulations. Under these restrictions, the aggregate amount of the loans to any insider and the insider’s related interests may not exceed the loans-to-one-borrower limit applicable to national banks (which is generally 15% of unimpaired capital and unimpaired surplus). Total loans by a savings bank to all its insiders and insiders’ related interests in the aggregate may not exceed the savings bank’s unimpaired capital and unimpaired surplus. Loans to an executive officer, with certain exceptions such as loans for the education of the officer’s children and certain loans secured by the officer’s primary residence, may not exceed the greater of $25,000 or 2.5% of the savings bank’s unimpaired capital and unimpaired surplus, but in no event more than $100,000. Under rules proposed by the Federal Reserve Board and the FDIC on July 31, 2026, loans to executive officers generally would be limited to the lower of 2.5% of unimpaired capital and unimpaired surplus or $400,000, with the upper limit dollar threshold automatically updated every five years utilizing nominal GDP. Regulation O also requires that any proposed loan to an insider or a related interest of that insider be approved in advance by a majority of the board of directors of the savings bank, with any interested director not participating in the voting, if such loan, when aggregated with any existing loans to that insider and the insider’s related interests, would exceed either $500,000 or the greater of $25,000 or 5% of the savings bank’s unimpaired capital and surplus. Under rules proposed by the Federal Reserve Board and the FDIC on July 31, 2026, prior board approval generally would be required whenever aggregate extensions of credit to an insider exceed the lower of 5% percent of unimpaired capital and unimpaired surplus or $2 million, with the upper limit dollar threshold automatically updated every five years utilizing nominal GDP. Generally, such loans must be made on substantially the same terms as, and follow credit underwriting procedures that are no less stringent than, those that are prevailing at the time for comparable transactions with other persons and must not present more than a normal risk of collectability.

Anti-tying Restrictions

Wisconsin savings banks, such as Marathon Bank, are subject to the prohibitions on certain tying arrangements. Subject to certain exceptions, a savings bank is prohibited from extending credit to or offering any other service to a customer, or fixing or varying the consideration for such extension of credit or service, on the condition that such customer obtain some additional service from the institution or certain of its affiliates or not obtain services of a competitor of the institution.

Examinations and Assessments

Marathon Bank is required to file periodic reports with and is subject to periodic examinations by the WDFI and the FDIC. Federal regulations require annual on-site examinations for all depository institutions except certain well-capitalized and highly rated institutions with assets of less than $3 billion, which are examined every 18 months. In July 2026, the 21st Century ROAD to Housing Act increased the asset threshold of institutions subject to the 18-month cycle to $6.0 billion. Marathon Bank is required to pay examination fees and annual assessments to fund its supervision.

Customer Privacy

Under Wisconsin and federal law and regulations, savings banks, such as Marathon Bank, are required to develop and maintain privacy policies relating to information on its customers, restrict access to and establish procedures to protect customer data. Applicable privacy regulations further restrict the sharing of non-public customer data with non-affiliated parties if the customer requests.

Cyber Security

The federal banking agencies recently adopted rules providing for new notification requirements for banking organizations and their service providers for significant cybersecurity incidents. Specifically, the new rules require a banking organization to notify its primary federal regulator as soon as possible, and no later than 36 hours after, the banking organization determines that a “computer-security incident” rising to the level of a “notification incident” has occurred. Notification is required for incidents that have materially affected or are reasonably likely to materially affect the viability of a banking organization’s operations, its ability to deliver banking products and services, or the stability of the financial sector. Service providers are required under the rule to notify affected banking organization customers as soon as possible when the provider determines that it has experienced a computer-security incident that has materially affected or is reasonably likely to materially affect the banking organization’s customers for four or more hours.

Community Reinvestment Act

Under the Community Reinvestment Act, Marathon Bank has a continuing and affirmative obligation consistent with its safe and sound operation to help meet the credit needs of its entire community, including low- and moderate-income neighborhoods. The Community Reinvestment Act does not establish specific lending requirements or programs for financial institutions nor does it limit an institution’s discretion to develop the types of products and services that it believes are best suited to its particular community, consistent with the Community Reinvestment Act. The Community Reinvestment Act requires the FDIC, in connection with its examination of Marathon Bank, to assess Marathon Bank’s record of meeting the credit needs of its community and to take that record into account in the FDIC’s evaluation of certain applications by Marathon Bank. For example, the regulations specify that a bank’s Community Reinvestment Act performance will be considered in its expansion (e.g., branching or merger) proposals and may be the basis for approving, denying or conditioning the approval of an application. As of the date of its most recent regulatory examination, Marathon Bank was rated “satisfactory” with respect to its Community Reinvestment Act compliance.

On October 24, 2023, the FDIC and the other federal banking agencies issued a final rule (the “2023 CRA Rule”) to replace the CRA regulations adopted by the agencies in 1995 (the “1995 CRA Regulations”). Legal challenges pushed back the implementation date and compliance deadlines of the 2023 CRA Rule. On July 16, 2025, the federal banking agencies issued a joint notice of proposed rulemaking, which has not been finalized, to rescind the 2023 CRA Rule and reinstate the 1995 CRA Regulations, with certain conforming and technical amendments. On July 31, 2026, instead of adopting the 2025 proposal, the FDIC and the OCC issued a new notice of proposed rulemaking for the CRA framework (the “2026 Proposed CRA Rule”). During the transition period, the 1995 CRA Regulations remain applicable.

The 2026 Proposed CRA Rule would retain the key elements of the 1995 CRA Regulations, with targeted substantive, technical and process-oriented amendments. Marathon Bank would continue to be classified as a small bank under the 2026 Proposed CRA Rule, which proposes to increase the total asset threshold from the current less than $412 million to less than $1 billion. Under the 2026 Proposed CRA Rule, banks such as Marathon Bank with $10.0 billion or less in assets would not be subject to CRA data collection, maintenance and reporting requirements and would receive more flexible CRA supervision. Marathon Bancorp cannot predict whether the FDIC will adopt the 2026 Proposed CRA Rule as proposed, with modifications, or at all.

Federal Home Loan Bank System

The Federal Home Loan Bank System, consisting of 11 Federal Home Loan Banks, is under the jurisdiction of the Federal Housing Finance Board. The designated duties of the Federal Housing Finance Board are to supervise the Federal Home Loan Banks; ensure that the Federal Home Loan Banks carry out their housing finance mission; ensure that the Federal Home Loan Banks remain adequately capitalized and able to raise funds in the capital markets; and ensure that the Federal Home Loan Banks operate in a safe and sound manner.

Marathon Bank, as a member of the Federal Home Loan Bank of Chicago, is required to acquire and hold shares of capital stock in the Federal Home Loan Bank of Chicago in specified amounts. Marathon Bank is in

compliance with this requirement with an investment in Federal Home Loan Bank of Chicago stock of $1.5 million at June 30, 2026.

Among other benefits, the Federal Home Loan Banks provide a central credit facility primarily for member institutions. It is funded primarily from proceeds derived from the sale of consolidated obligations of the Federal Home Loan Bank System. It makes advances to members in accordance with policies and procedures established by the Federal Housing Finance Board and the board of directors of the Federal Home Loan Bank of Chicago. At June 30, 2026, Marathon Bank had $20.0 million of advances from the Federal Home Loan Bank of Chicago.

Other Regulations

Interest and other charges collected or contracted for by Marathon Bank are subject to state usury laws and federal laws concerning interest rates. Marathon Bank’s operations are also subject to federal laws applicable to credit transactions, such as the:

The operations of Marathon Bank also are subject to the:

Holding Company Regulation

General**.** Marathon Bancorp is a bank holding company within the meaning of the Bank Holding Company Act of 1956. As such, Marathon Bancorp is registered with the Federal Reserve Board and subject to the regulation, examination, supervision and reporting requirements applicable to bank holding companies. In addition, the Federal Reserve Board has enforcement authority over Marathon Bancorp and its non-savings institution subsidiaries. Among other things, this authority permits the Federal Reserve Board to restrict or prohibit activities that are determined to be a

serious risk to the subsidiary savings institution. Acquisitions of additional banks or savings institutions generally require the prior approval of the Federal Reserve Board.

Permissible Activities. A bank holding company is generally prohibited from engaging in non-banking activities, or acquiring direct or indirect control of more than 5% of the voting securities of any company engaged in non-banking activities. One of the principal exceptions to this prohibition is for activities found by the Federal Reserve Board to be so closely related to banking or managing or controlling banks as to be a proper incident thereto. Some of the principal activities that the Federal Reserve Board has determined by regulation to be so closely related to banking are: (i) making or servicing loans; (ii) performing certain data processing services; (iii) providing discount brokerage services; (iv) acting as fiduciary, investment or financial advisor; (v) leasing personal or real property; (vi) making investments in corporations or projects designed primarily to promote community welfare; and (vii) acquiring a savings and loan association whose direct and indirect activities are limited to those permitted for bank holding companies.

The Gramm-Leach-Bliley Act of 1999 authorized a bank holding company that meets specified conditions, including being “well capitalized” and “well managed,” to opt to become a “financial holding company” and thereby engage in a broader array of financial activities than previously permitted. Such activities can include insurance underwriting and investment banking. Marathon Bancorp did not elect “financial holding company” status.

Capital. Consolidated regulatory capital requirements identical to those applicable to subsidiary banks generally apply to bank holding companies. However, the Federal Reserve Board has provided a “Small Bank Holding Company” exception to its consolidated capital requirements, and bank holding companies with less than $3.0 billion of consolidated assets are not subject to the consolidated holding company capital requirements unless otherwise directed by the Federal Reserve Board. As a result, the Federal Reserve Board’s consolidated holding company regulatory capital requirements do not presently apply to Marathon Bancorp.

Source of Strength. The Federal Reserve Board has issued regulations requiring that all bank holding companies serve as a source of strength to their subsidiary depository institutions by providing financial, managerial and other support in times of an institution’s distress.

Dividends and Stock Repurchases. The Federal Reserve Board has issued a policy statement regarding the payment of dividends by holding companies. In general, the policy provides that dividends should be paid only out of current earnings and only if the prospective rate of earnings retention by the holding company appears consistent with the organization’s capital needs, asset quality and overall supervisory financial condition. Separate regulatory guidance provides for prior consultation with Federal Reserve Bank staff concerning dividends in certain circumstances such as when the company’s net income for the past four quarters, net of dividends previously paid over that period, is insufficient to fully fund the dividend, the proposed dividend is not covered by earnings for the period for which it is being paid or the company’s overall rate or earnings retention is inconsistent with the company’s capital needs and overall financial condition. The ability of a bank holding company to pay dividends may be restricted if a subsidiary savings bank becomes undercapitalized.

The Federal Reserve Board regulatory guidance also states that a bank holding company should consult with Federal Reserve Bank supervisory staff prior to redeeming or repurchasing common stock or perpetual preferred stock if the bank holding company is experiencing financial weaknesses or the repurchase or redemption would result in a net reduction, at the end of a quarter, in the amount of such equity instruments outstanding compared with the beginning of the quarter in which the redemption or repurchase occurred.

There is a separate requirement that a bank holding company give the Federal Reserve Board prior written notice of any purchase or redemption of then outstanding equity securities if the gross consideration for the purchase or redemption, when combined with the net consideration paid for all such purchases or redemptions during the preceding 12 months, is equal to 10% or more of the company’s consolidated net worth. The Federal Reserve Board may disapprove such a purchase or redemption if it determines that the proposal would constitute an unsafe and unsound practice, or would violate any law, regulation, Federal Reserve Board order or directive, or any condition imposed by, or written agreement with, the Federal Reserve Board. There is an exception to this approval requirement for well-capitalized bank holding companies that meet certain other conditions.

These regulatory policies may affect the ability of Marathon Bancorp to pay dividends, repurchase shares of common stock or otherwise engage in capital distributions.

Acquisition of Bank Holding Company

Under the Change in Bank Control Act, no person (including a company), or group of persons acting in concert, may acquire control of a bank holding company unless the Federal Reserve Board has been given 60 days’ prior written notice and not disapproved the proposed acquisition. The Federal Reserve Board considers several factors in evaluating a notice, including the financial and managerial resources of the acquirer and competitive effects. Control, as defined under the Change in Bank Control Act and applicable regulations, means the power, directly or indirectly, to direct the management or policies of the company or to vote 25% or more of any class of voting securities of the company. Acquisition of more than 10% of any class of a bank holding company’s voting securities constitutes a rebuttable presumption of control under certain circumstances, including where, as is the case with Marathon Bancorp, the issuer has registered securities under Section 12 of the Securities Exchange Act of 1934.

In addition, federal regulations separately provide that no company may acquire control (as defined in the Bank Holding Company Act) of a bank holding company without the prior approval of the Federal Reserve Board. Control, as defined under the Bank Holding Company Act and Federal Reserve Board regulations, means ownership, control or power to vote 25% or more of any class of voting stock, control in any manner over the election of a majority of the company’s directors, or a determination by the regulator that the acquiror has the power to exercise, directly or indirectly, a controlling influence over the management or policies of the company. Any company that acquires such control becomes a “bank holding company” subject to registration, examination and regulation by the Federal Reserve Board. In March 2020, the Federal Reserve Board adopted a final rule, effective September 30, 2020, that revised its framework for determining whether a company has a “controlling influence” over a bank holding company for that purpose.

Federal Securities Laws

Marathon Bancorp’s common stock is registered with the SEC under the Securities Exchange Act of 1934 (the “Exchange Act”). Marathon Bancorp is subject to the information, proxy solicitation, insider trading restrictions and other requirements under the Exchange Act.

On May 19, 2026, the SEC proposed amendments to streamline filer status categories for companies subject to reporting obligations under the Exchange Act into two primary categories: “large accelerated filers” and “non-accelerated filers.” The public float requirement forlarge accelerated filer status would be revised from $700 million to $2.0 billion and would require a registrant to have been subject to Exchange Act reporting requirements for at least 60 consecutive calendar months before it could become a large accelerated filer. The proposal would eliminate the accelerated filer and smaller reporting company categories as separate filer status categories and would instead extend existing accommodations and scaled disclosure requirements currently available to smaller reporting companies and emerging growth companies to all non-accelerated filers. The proposal is intended to simplify the existing reporting framework, under which companies may be required to evaluate overlapping filer statuses, including large accelerated filer, accelerated filer, non-accelerated filer, smaller reporting company and emerging growth company status. Non-accelerated filers such as Marathon Bancorp would also benefit from certain emerging growth company-style accommodations, including exemptions from pay-versus-performance disclosure and shareholder advisory votes on executive compensation, including say-on-pay, say-on-frequency and golden parachute advisory votes.

On May 5, 2026, the SEC proposed rule amendments that would permit Exchange Act reporting companies to file semiannual reports on a new Form 10-S in lieu of quarterly reports on Form 10-Q. The election would be optional and made annually through a registrant's Form 10-K cover page. If adopted, electing companies would file one semiannual report and one annual report per fiscal year instead of three quarterly reports and one annual report. The proposal would also amend Regulation S-X to facilitate semiannual reporting and simplify financial statement age requirements.

As of the date of this filing, both proposals remain pending and have not been adopted. Marathon Bancorp cannot predict whether the SEC will adopt the proposed amendments as proposed, with modifications, or at all.