X0508 4 2023-08-16 0 0000036029 FIRST FINANCIAL BANKSHARES INC FFIN 0001642844 Roewe Randall Allen P O BOX 701 ABILENE TX 79604 0 1 0 0 Chief Risk Officer 0 Common Stock 2023-08-16 4 F 0 65 29.53 D 27667 D Common Stock 2023-08-16 4 A 0 1693 0.00 A 29360 D Common Stock 2023-08-16 4 D 0 275 D 29085 D Employee Stock Option, Right to Buy 29.53 2023-08-16 4 A 0 5954 0.00 A 2033-08-16 Common Stock 5954 5954 D Deferred Stock Units 2023-08-16 4 A 0 275 A Common Stock 275 275 D The reporting person elected, in accordance with the Registrant's 2021 Omnibus Stock and Incentive Plan, to exercise his right to have the Registrant withhold 65 shares of the Registrant's common stock to pay income taxes related to vesting of previously granted restricted stock units. Reflects grant of restricted stock units (RSUs) which vest in three approximately equal installments on each of the three anniversaries of the grant date. In connection with the vesting on August 16, 2023, of 275 restricted stock units previously granted to Mr. Roewe on August 16, 2022, Mr. Roewe's receipt of 275 shares of common stock was deferred resulting in Mr. Roewe's receipt instead of 275 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. Roewe is therefore reporting the disposition of 275 restricted stock units in exchange for an equal number of shares of deferred stock units under the SERP, which are payable upon Mr. Roewe's termination of employment. The options vest 33.33% after one year from the grant date, 66.66% after the second year, and 100% after the third year. By: Michelle S. Hickox Attorney in Fact for Randall A. Roewe 2023-08-18