X0609 4 2026-06-03 0001835385 Marathon Bancorp, Inc. /MD/ MBBC 0001855946 Spatz Nora false 500 SCOTT STREET WAUSAU WI 54403 1 EVP and CAO 0 Common Stock 2026-06-03 4 P 0 722 13.748 A 36423 I By 401(k) Common Stock 2026-06-04 4 P 0 74 13.7678 A 34497 I By 401(k) Common Stock 2026-06-05 4 P 0 320 14.2481 A 36817 I By 401(k) Common Stock 2026-06-08 4 P 0 197 14.241 A 37014 I By 401(k) Common Stock 2026-06-09 4 P 0 1904 14.50 A 38918 I By 401(k) Common Stock 2026-06-10 4 P 0 602 14.75 A 39520 I By 401(k) Common Stock 21149 D Common Stock 1598 I By Trust Common Stock 1149 I As custodian Common Stock 2109 I By ESOP Common Stock 1372 I By Spouse Stock Options 8.1300 2023-06-28 2032-06-28 Common Stock 2400 2400 D Stock Options 6.4800 2024-05-16 2033-05-16 Common Stock 2883 2883 D The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $13.655 to $13.75, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnote (1) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $13.75 to $14.00, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnote (2) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $14.00 to $14.25, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnote (3) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $14.18 to $14.25, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnote (4) to this Form 4. Includes shares of restricted stock which vest at a rate of 20% per year commencing on June 28, 2023. Includes shares of restricted stock which vest at a rate of 20% per year commencing on May 16, 2024. Stock options vest at a rate of 20% per year commencing on June 28, 2023. Stock options vest at a rate of 20% per year commencing on May 16, 2024. /s/ Benjamin Azoff, pursuant to power of attorney 2026-06-11