ATI INC — Director's Dealing 2026

Jan 7, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ATI INC (ATI)
CIK: 0001018963
Period of Report: 2026-01-05

Reporting Person: Harris Timothy J (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-01-05	Common Stock, par value $0.10 per share	A	2677	—	Acquired	100987	Direct
2026-01-05	Common Stock, par value $0.10 per share	M	70442	$0.00	Acquired	171429	Direct
2026-01-05	Common Stock, par value $0.10 per share	F	30918	$121.08	Disposed	140511	Direct
2026-01-05	Common Stock, par value $0.10 per share	A	46318	$0.00	Acquired	186829	Direct
2026-01-05	Common Stock, par value $0.10 per share	F	20283	$121.08	Disposed	166546	Direct
2026-01-05	Common Stock, par value $0.10 per share	F	3359	$121.08	Disposed	163187	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2026-01-05	Performance Stock Unit	$0.00	M	25641	Disposed	2026-12-31	Common Stock, par value $0.10 per share (70442)	Direct

Footnotes

F1: 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.

F2: Awarded under the Issuer's 2022 Incentive Plan.

F3: Settlement of one-half of certain Performance Stock Units awarded in 2022 ("2022 Breakout Performance Units"), each of which represented a contingent right to receive shares of the Issuer's Common Stock if the Issuer's Common Stock achieved specified target market prices (based on a 20-trading day average) on the New York Stock Exchange ("NYSE") for at least 20 consecutive trading days (the "20-day Average Market Price") prior to December 31, 2025, up to a maximum of three shares per Unit. The shares underlying one-half of the 2022 Breakout Performance Units became payable as of January 5, 2026 following certification of the Issuer's achievement of the relevant performance criteria by the Compensation and Leadership Development Committee of the Company's Board of Directors (the "CLDC"). The remaining half of the 2022 Breakout Performance Units are scheduled by their terms to become payable in early 2027.

F4: Shares withheld for the payment of taxes in connection with the settlement of 2022 Breakout Performance Units.

F5: Represents the average of the high and low trading prices for one share of the Issuer's Common Stock on the NYSE on January 5, 2026.

F6: Settlement of performance-vested restricted stock units that were granted in 2023, the vesting of which was contingent on the Issuer's total shareholder return relative to a specified peer group during the period from January 1, 2023 through December 31, 2025 (the "2023-2025 PSUs"). The shares underlying the 2023-2025 PSUs became payable as of January 5, 2026 following certification of the Issuer's achievement of the relevant performance criteria by the CLDC.

F7: Shares withheld for the payment of taxes in connection with the settlement of the 2023-2025 PSUs.

F8: Shares withheld for payment of taxes on restricted stock units awarded in 2023, 2024 and 2025. One third of each such award vested by the terms thereof on January 5, 2026.