X0508 4 2024-04-01 0000719220 S&T BANCORP INC STBA 0001920913 Nicholson Susan A 800 PHILADELPHIA STREET INDIANA PA 15701 1 Executive Vice President 0 Common Stock 2024-04-01 4 D 0 178 31.89 D 2990 D Common Stock 2024-04-01 4 F 0 145 31.89 D 2845 D Common Stock 2024-04-01 4 F 0 149 31.89 D 2696 D Common Stock 2024-04-01 4 F 0 212 31.89 D 2484 D Common Stock 2024-04-01 4 M 0 545 31.89 A 3029 D Common Stock 2024-04-01 4 F 0 239 31.89 D 2790 D Common Stock 2024-04-01 4 M 0 637 31.89 A 3427 D Common Stock 2024-04-01 4 F 0 279 31.89 D 3148 D Restricted Stock Units 2024-04-01 4 M 0 545 0 D Common Stock 545 564 D Restricted Stock Units 2024-04-01 4 M 0 637 0 D Common Stock 637 1294 D Director Restricted Stock Units 2024-04-01 4 A 0 2073 0 A Common Stock 2073 2073 D Forfeiture of performance shares from the 2021 Long-Term Incentive Plan. Performance shares vested at 73%, between Threshold and Target level. Shares withheld upon vesting of Restricted Stock for payment of tax liability. 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. 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. 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. /s/ Susan L. Rager-Parr, attorney-in-fact for Susan A. Nicholson 2024-04-03