X0508 4/A 2025-04-01 2025-04-03 0000719220 S&T BANCORP INC STBA 0001538345 Drahnak Stephen A. 800 PHILADELPHIA STREET INDIANA PA 15701 1 Executive Vice President 0 Common Stock 2025-04-01 4 M 0 3585 37.15 A 15004.953 D Common Stock 2025-04-01 4 F 0 1569 37.15 D 13435.953 D Common Stock 2025-04-01 4 M 0 710 37.15 A 14145.953 D Common Stock 2025-04-01 4 F 0 311 37.15 D 13834.953 D Common Stock 2025-04-01 4 M 0 714 37.15 A 14548.953 D Common Stock 2025-04-01 4 F 0 313 37.15 D 14235.953 D Common Stock 2025-04-01 4 M 0 756 37.15 A 14991.953 D Common Stock 2025-04-01 4 F 0 331 37.15 D 14660.953 D Common Stock 8021.4882 I 401-k Common Stock 293 I Child Restricted Stock Units 2025-04-01 4 A 0 3585 0 A Common Stock 3585 3585 D Restricted Stock Units 2025-04-01 4 M 0 3585 0 D Common Stock 3585 0 D Restricted Stock Units 2025-04-01 4 M 0 710 0 D Common Stock 710 0 D Restricted Stock Units 2025-04-01 4 M 0 714 0 D Common Stock 714 738 D Restricted Stock Units 2025-04-01 4 M 0 756 0 D Common Stock 756 1536 D Restricted Stock Units 2025-04-01 4 A 0 1947 0 A Common Stock 1947 1947 D Upon vest, automatically converts into equal number of shares of common stock. Shares of common stock withheld for payment of tax liability for vested and converted RSU's. The number of shares initially reported was incorrect. The correct number of S&T Bancorp. shares owned by the child on 1/1/2012 was 293. Acquired upon achievement of certain performance criteria pursuant to the performance-based restricted stock units granted April 1, 2022, under the Issuer's 2022 Long Term Incentive Plan. The performance period for the restricted stock units was January 1, 2022, until December 31, 2024, with achievement of the applicable performance criteria subject to determination by the Issuer's Compensation Committee. This determination was obtained on March 25, 2025. The restricted performance units awarded on April 1, 2022 vesting on April 1, 2025. Vested shares will be delivered to the reporting person upon vesting. Each restricted stock unit represents a contingent right to receive one share of S&T Bancorp, Inc. common stock. The restricted stock units vest in three equal annual installments beginning April 1, 2023. Vested shares will be delivered to the reporting person upon vesting. The restricted stock units vest in three equal annual installments beginning April 1, 2024. Vested shares will be delivered to the reporting person upon vesting. Correction to the name of the award. It is not a Director's award, but officer award. All other aspects of the award, including date of award, number of shares, and vesting remain unchanged. The restricted stock units vest in three equal annual installments beginning April 1, 2025. Vested shares will be delivered to the reporting person upon vesting. The restricted stock units vest in three equal annual installments beginning April 1, 2025. In accordance with a pre-established deferral election made by the reporting person, vested shares will be delivered to the reporting person upon separation from service or sooner upon the occurrence of certain events. Filing delay due by April 3, 2025, caused by software unable to attach footnotes to awards. The restricted stock units vest in three equal annual installments beginning April 1, 2026. Vested shares will be delivered to the reporting person upon vesting. /s/ Susan L. Rager-Parr, attorney-in-fact for Stephen A. Drahnak 2025-04-04