X0508 4 2026-01-05 0001018963 ATI INC ATI 0001880164 Miller Michael Benjamin C/O ATI INC. 2021 MCKINNEY AVENUE, SUITE 1100 DALLAS TX 75201 false true false false VP Chief Accounting Officer false Common Stock, par value $0.10 per share 2026-01-05 4 A false 854 0 A 8426 D Common Stock, par value $0.10 per share 2026-01-05 4 F false 374 121.08 D 8052 D Award of restricted stock units, which are settled in shares of stock upon vesting. The award vests in three equal annual installments on each of the first three anniversaries of the grant date. Awarded under the Issuer's 2022 Incentive Plan. Shares withheld for the payment of taxes on restricted stock units awarded in 2024 and 2025. One-third of each such award vested by the terms thereof on January 5, 2026. Represents the average of the high and low trading prices for one share of the Issuer's Common Stock on the New York Stock Exchange on January 5, 2026. /s/ Amanda J. Skov, Attorney-in-Fact for Michael B. Miller 2026-01-07