X0306 4 2022-08-16 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 Common Stock 2022-08-16 4 D 0 3272 0.00 D 929420 I By Trust Common Stock 2022-08-16 4 A 0 10394 0.00 A 939814 I By Trust Common Stock 496004 I By Partnership Common Stock 448310 I By Partnership Employee Stock Option, Right to Buy 47.19 2022-08-16 4 A 0 21326 0.00 A 2032-08-16 Common Stock 21326 21236 D Deferred Stock Units 0.00 2022-08-16 4 A 0 3272 0.00 A Common Stock 3272 3272 D In connection with the vesting on August 16, 2022 of 3,272 restricted stock units previously granted to Mr. Dueser on August 16, 2021, Mr. Dueser's receipt of 3,272 shares of common stock was deferred, resulting in Mr. Dueser's receipt instead of 3,272 shares of deferred stock units into the First Financial Bankshares, Inc. Supplemental Executive Retirement Plan, as amended and restated effective July 26, 2022 (the "SERP"). Mr. Dueser is therefore reporting the disposition of 3,272 restricted stock units in exchange for an equal number of shares of deferred stock units under the SERP, which are payable upon Mr. Dueser's termination of employment. Represents shares held by several trusts of which Mr. Dueser is trustee, settlor and beneficiary. Reflects grant of restricted stock units (RSUs) which vest in three approximately equal installments on each of the three anniversaries of the grant date. 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. The options vest 20% after one year from the grant date, 40% after the second year, 60% after the third year, 80% after the fourth year and 100% after the fifth year. By: James R. Gordon Attorney in Fact for F. Scott Dueser 2022-08-18