ATI (ATI) 8-KRegulation FD Disclosure

ATI Inc.'s ("the Company") Q4 2023 and full year 2023 guidance released on November 2, 2023 did not reflect the change in accounting policy discussed below. There is no significant difference between our expectations regarding Adjusted Earnings Per Share (EPS) for Q4 2023, which reflect the change in accounting policy, and the Adjusted EPS that we anticipated for the quarter without giving effect to the change in accounting policy, largely due to pension annuitization transactions executed in Q4 2023. Therefore, the Adjusted Q4 2023 EPS guidance range of $0.57 - $0.67 previously presented on page 7 of the Q3 Earnings Presentation, released on November 2, 2023, remains unchanged. However, the Company's change in accounting policy does require an adjustment to the full year Adjusted EPS range estimate, as previously released on November 2, 2023. Adjusting for the accounting policy change, Adjusted EPS for year-to-date September 2023 increases from $1.63 to $1.92. Accordingly, the full year 2023 Adjusted EPS range estimate increases from $2.20 - $2.30 to $2.49 to $2.59, with the new midpoint of the range at $2.54. This revised range incorporates no additional changes in estimates associated with Q4 2023 and full year 2023.

During the fourth quarter of 2023, the Company voluntarily changed the method of accounting for recognizing actuarial gains and losses for its defined benefit pension plans. Under the accounting method change, remeasurement of the projected benefit obligation and plan assets for defined benefit pension plans are immediately recognized in earnings through net periodic pension benefit cost within nonoperating retirement benefit expense on the consolidated statements of operations, with pension plans to be remeasured annually in the fourth quarter or on an interim basis as triggering events require remeasurement. Prior to this accounting method change, the Company deferred the recognition of these gains and losses in accumulated other comprehensive loss on the consolidated balance sheet. The accumulated actuarial gains/losses were then amortized into net periodic benefit costs within nonoperating retirement benefit expense on the consolidated statement of operations over the average expected remaining life of plan participants. While the historical accounting principle was acceptable, we believe that the current accounting policy is preferable because it provides a better representation of the operating results of the Company and the economic performance of plan assets in relation to the measurement of its benefit obligations for the period. The change in accounting will more clearly reflect the current period impact of the Company’s pension asset investment strategy to readers of the financial statements.

Beginning with the fourth quarter and fiscal year ended December 31, 2023, the Company's financial information will reflect the impact of the change in accounting principle, with prior periods retrospectively adjusted. As of January 1, 2021, this change resulted in a cumulative effect decrease to retained earnings of $1.07 billion with a corresponding offset to accumulated other comprehensive loss.