X0609 4 2026-08-14 0000036029 FIRST FINANCIAL BANKSHARES INC FFIN 0001573445 Hickox Michelle S false P O BOX 701 ABILENE TX 79604 false true false false EVP/CFO false Common Stock 2016-08-14 4 D false 2337 D 9524 D Common Stock 2026-08-16 4 D false 1354 D 8170 D Common Stock 14600 I By IRA Deferred Stock Units 2026-08-14 4 A false 2337 A Common Stock 2337 12343 D Deferred Stock Units 2026-08-16 4 A false 1354 A Common Stock 1354 13697 D In connection with the vesting on August 14, 2026, of 2,337 restricted stock units previously granted to the reporting person, the reporting person's receipt of 2,337 shares of common stock was deferred resulting in the reporting person's receipt instead of 2,337 shares of deferred stock units into the First Financial Bankshares, Inc. Supplemental Executive Retirement Plan, as amended and restated effected July 26, 2022 (the "SERP"). The reporting person is therefore reporting the disposition of 2,337 restricted stock units in exchange for an equal number of deferred stock units under the SERP, which are payable upon the reporting person's termination. In connection with the vesting on August 16, 2026, of 1,354 restricted stock units previously granted to the reporting person, the reporting person's receipt of 1,354 shares of common stock was deferred resulting in the reporting person's receipt instead of 1,354 shares of deferred stock units into the First Financial Bankshares, Inc. Supplemental Executive Retirement Plan, as amended and restated effected July 26, 2022 (the "SERP"). The reporting person is therefore reporting the disposition of 1,354 restricted stock units in exchange for an equal number of deferred stock units under the SERP, which are payable upon the reporting person's termination. By: Michelle S. Hickox 2026-08-18