X0508 4 2024-02-20 0 0000036029 FIRST FINANCIAL BANKSHARES INC FFIN 0001243211 DUESER F SCOTT P. O. BOX 701 ABILENE TX 79604-0701 1 1 0 0 Chairman, President and CEO 0 Common Stock 2024-02-20 4 M 0 20000 21.18 A 951065 I By Trust Common Stock 496004 I By Partnership Common Stock 448310 I By Partnership Employee Stock Option, Right to Buy 21.18 2024-02-20 4 M 0 20000 21.18 D 2023-06-12 2027-06-12 Common Stock 20000 0 D Represents shares held by several trusts of which Mr. Dueser is trustee, settlor and beneficiary. Represents shares that are owned by a family limited partnership of which Mr. Dueser serves as manager of the general partner and to which he disclaims beneficial ownership with respect to 372,003 shares. This report should not be deemed an admission that Mr. Dueser is the beneficial owner of these shares for purposes of Section 16 or any other purpose. Represents shares that are owned by a family limited partnership of which Mr. Dueser serves as manager of the general partner and to which he disclaims beneficial ownership with respect to 319,636 shares. This report should not be deemed an admission that Mr. Dueser is the beneficial owner of these shares for purposes of Section 16 or any other purpose. By: Michelle S. Hickox Attorney in Fact for F. Scott Dueser 2024-02-20