Form of Performance-Vested Restricted Stock Unit Agreement

This Performance-Vested Restricted Stock Unit Agreement (this “Agreement”) is made as of the __ day of January, 2023 (the “Grant Date”) by and between ATI Inc., a Delaware company (the “Company”), and #ParticipantName+C# (the “Participant”).

WHEREAS, the Company sponsors and maintains the Allegheny Technologies Incorporated 2022 Incentive Plan (the “Incentive Plan”);

WHEREAS, the Company desires to encourage the Participant to remain an employee of the Company and, during such employment, to contribute substantially to the financial performance of the Company;

WHEREAS, to provide that incentive, the Company awarded the Participant the number of performance-vested restricted stock units (singular “PSU” and plural “PSUs”) shown below, related to the common stock of the Company, $0.10 par value per share (“Common Stock”), subject to the terms and conditions of this Agreement, including restrictive covenants, set forth herein;

WHEREAS, the PSUs are subject to the Company’s attainment of the performance requirements set forth in Section 3 of this Agreement (the “Performance Goals”) and the Participant’s ongoing employment by the Company until the end of the Performance Period, except as otherwise provided herein;

WHEREAS, the Company and the Participant desire to evidence the award of the PSUs and the terms and conditions applicable thereto in this Agreement; and

WHEREAS, capitalized terms used but not defined herein shall have the meanings ascribed to them in the Incentive Plan.

NOW, THEREFORE, in consideration of the mutual promises and covenants contained herein, including the Restrictive Covenants set forth in Section 11 of this Agreement, and intending to be legally bound, the Company and the Participant agree as follows:

1.Grant of PSUs. The Company hereby grants to the Participant a target amount of #QuantityGranted# PSUs (subject to adjustment as provided in Section 3(d) of the Incentive Plan) as of the Grant Date. The target amount of PSUs represents the right to receive an equivalent number of Shares upon the achievement of the Performance Goals referenced in Section 3 below at the target level of achievement set forth herein, subject to the terms and conditions set forth in this Agreement and the Incentive Plan. The actual number of Shares in respect of the PSUs that become earned and vested shall be determined based on the level of achievement of the Performance Goals, as determined by the Committee in accordance with Section 3 below (or Section 7(a), upon a Change in Control), except as otherwise provided herein.

2. Performance Period. The overall Performance Period for the PSUs shall be the period commencing on January 1, 2023 and ending on December 31, 2025, and which shall consist of four individual independent performance measurement periods (each a “Measurement Period”) commencing on January 1, 2023 and ending on each of June 30, 2024, December 31, 2024, June 30, 2025, and December 31, 2025.

3. Performance Goals and Payment of PSUs.

The PSUs may be earned based on the achievement of the Performance Goals measured over each Measurement Period within the Performance Period as described below (except as otherwise provided in Section 7(a) below upon a Change in Control) and subject to the Participant’s continuous employment with the Company through the conclusion of the Performance Period, except as otherwise provided in Section 4 of this Agreement. As indicated in the table below, a portion of the target amount of PSUs is allocated to, and may be earned with respect to performance for, each individual independent Measurement Period:

(a) The number of PSUs that become earned and vested under this Agreement shall be determined in accordance with the schedule below based on the Company’s Total Shareholder Return (“TSR”) during each Measurement Period within the Performance Period (determined as set forth on Appendix A hereto), as compared to that of the TSR Peer Group set forth on Appendix A hereto and calculated in accordance with the methodology set forth on Appendix A hereto, with the payout percentage applied to the portion of the PSUs allocated to each Measurement Period.

Percentile Performance Payout (percentage of Target)

In each Measurement Period of PSUs allocated to Measurement Period

Threshold: 30th 50%

Target: 50th 100%

Maximum: 80th or more 200%

(b) As soon as administratively practicable following the end of the Performance Period, the Committee shall determine the TSR achieved by the Company for each individual independent Measurement Period and during the Performance Period and the resulting extent to which the PSUs have been earned during the Performance Period, calculated as the sum of all PSUs allocated to and earned with respect to each Measurement Period, with such total reduced by the limit on the total payout if TSR was negative for the Performance Period.

4. Termination of Service Prior to the End of the Performance Period. Except as otherwise provided in this Section 4, if, prior to the end of the Performance Period, the Participant experiences a Termination of Service, whether initiated by either party and for any reason, all rights of the Participant to the PSUs shall terminate immediately and be forfeited in their entirety without compensation to the Participant, without regard to performance during any Measurement Period, and the forfeited PSUs shall be canceled.

(a) Termination of Service Due to Death or Disability Prior to a Change in Control. If, during the Performance Period and prior to a Change in Control, the Participant experiences a Termination of Service due to the Participant’s death or Disability (as defined in Appendix B), then the PSUs shall be deemed to have been earned by the Participant in the target amount set forth in Section 1 hereof, all rights of the Participant with respect to such target amount of PSUs shall become immediately vested as of the date of such Termination of Service, and the Shares with respect thereto shall be delivered as soon as reasonably practicable (and in no event later than thirty (30) days) following the date of such Termination of Service, provided that, prior to the delivery date, the Participant does not breach any of the restrictive covenants set forth herein. Notwithstanding the foregoing, if the Participant experiences a Termination of Service due to Disability (other than during the two (2)-year period following a Section 409A CIC) and the Participant is (or during the Performance Period would be) Retirement eligible (without regard to any consent requirement), such Shares shall be delivered on the Scheduled Settlement Date (as defined in Section 5), provided that, prior to the delivery date, the Participant does not breach any of the restrictive covenants set forth herein.

(b) Termination of Service Due to Retirement Prior to a Change in Control. If, during the Performance Period and prior to a Change in Control, the Participant experiences a Termination of Service due to the Participant’s Retirement (as defined in Appendix B), then the continued service requirement shall lapse and the number of vested Shares shall equal the product of (i) the number of Shares underlying the PSUs that would be earned based on the level of achievement of the TSR as determined by the Committee and (ii) a fraction, the numerator of which is equal to the number of months the Participant was employed by the Company during the Performance Period (including any month during which the Participant remained employed by the Company for at least fifteen (15) days)

and the denominator of which is equal to the total number of months in the Performance Period (the “Proration Fraction”), with the resulting number of vested Shares to be delivered on the Scheduled Payment Date, provided that, prior to the delivery date, the Participant does not breach any of the restrictive covenants set forth herein.

(c) Certain Terminations Following a Change in Control. If, during the Performance Period, a Participant experiences a Termination of Service (i) at any time following a Change in Control due to the Participant’s death, Disability or Retirement, or (ii) during the two (2)‑year period following a Change in Control due to a termination by the Company without Cause or a resignation by the Participant for Good Reason (as defined in Appendix B hereto), any Replacement Award (as defined in Section 7 below) granted in respect of the PSUs (for the avoidance of doubt, with the number of Shares subject to the PSUs to equal the number of Shares determined to be earned in accordance with Section 7(a) below and without proration upon Retirement) shall vest in full immediately upon the date of Termination of Service, and the Shares with respect thereto shall be delivered as soon as reasonably practicable (and in no event later than thirty (30) days) following the date of such Termination of Service, subject to any required delay under Section 12 below. Notwithstanding the foregoing, if (A) such Change in Control is not a Section 409A CIC or the Termination of Service due to Disability or Retirement occurs after the second anniversary of such Change in Control and (B) the Participant is (or during the Performance Period would be) Retirement eligible (without regard to any consent requirement) or the PSUs otherwise constitute nonqualified deferred compensation, subject to Section 409A of the Code the acceleration of which would result in tax penalties under Section 409A of the Code, such Shares shall be delivered as soon as reasonable practicable (and in no event later than thirty (30) days following December 31, 2025.

5. Settlement of the Earned and Vested PSUs.

6. Rights as a Stockholder. Until the issuance of the Shares subject to the PSUs (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company), no right to vote or receive dividends or any other rights as a holder of Common Stock shall exist with respect to the PSUs.

7. Change in Control.

8. Withholding. No later than the date as of which an amount first becomes includible in the gross income of the Participant or subject to any applicable tax for federal income tax purposes with respect to any PSUs, the Participant shall pay to the Company, or make arrangements satisfactory to the Company regarding the payment of, all federal, state and local income and employment taxes that are required by applicable laws and regulations to be withheld with respect to such amount. The Participant may direct the Company to deduct any such taxes from any payment otherwise due to the Participant, including the delivery of Shares that gives rise to the withholding requirement. The Company’s obligation to deliver the Shares underlying the PSUs (or to make a book-entry or other electronic notation indicating ownership of the Shares) is subject to the condition precedent that the Participant either pay or provide for the amount of any such withholding.

9. No Right to Continued Employment; Effect on Benefit Plans. This Agreement shall not confer upon the Participant any right with respect to continuance of his or her employment or other relationship, nor shall it interfere in any way with the right of the Company, or any of its direct or indirect subsidiaries, to terminate his or her employment or other relationship, at any time. Income realized by the Participant pursuant to this Agreement shall not be included in the Participant’s earnings for the purpose of any benefit plan in which the Participant may be enrolled or for which the Participant may become eligible, unless otherwise specifically provided for in such plan.

10. Participant Representations. In connection with the grant of the PSUs, the Participant represents the following:

11. Restrictive Covenants.

12. Section 409A. This Agreement and the PSUs granted hereunder are intended to comply with the requirements of Section 409A of the Code or an exemption or exclusion therefrom, and, with respect to PSUs that are subject to Section 409A of the Code, the Incentive Plan and this Agreement shall be interpreted and administered in all respects in accordance with Section 409A of the Code (including with respect to the application of any defined terms, such as Change in Control, to PSUs that constitute nonqualified deferred compensation, which defined terms shall be interpreted to have the meaning required by Section 409A of the Code to the extent required in order to avoid accelerated taxation and/or tax penalties under Section 409A of the Code). Each payment (including the delivery of Shares) under the PSUs that constitutes nonqualified deferred compensation subject to Section 409A of the Code shall be treated as a separate payment for purposes of Section 409A of the Code. In no event may the Participant, directly or indirectly, designate the calendar year of any payment to be made under this Agreement that constitutes nonqualified deferred compensation subject to Section 409A of the Code. Notwithstanding any other provision of this Agreement to the contrary, if the Participant is a “specified employee” within the meaning of Section 409A of the Code (as determined in accordance with the methodology established by the Company as in effect on the date of Termination of Service), amounts that constitute nonqualified deferred compensation within the meaning of Section 409A of the Code that would otherwise be payable by reason of the Participant’s Separation from Service during the six (6)-month period immediately following such Separation from Service shall instead be paid or provided on the earlier to occur of (i) the first business day following the date that is six (6) months following the Participant’s Separation from Service and (ii) the date of the Participant’s death.

13. Miscellaneous.

14. Clawback. The Participant acknowledges and agrees that PSUs granted hereunder and the Shares received in respect thereof shall be subject to the clawback provisions set forth in Section 15(j) of the Incentive Plan, the terms of any clawback policy that the Company may adopt and that is applicable to the Participant, as it may be amended from time to time, and any provision of applicable law relating to cancellation, rescission, payback or recoupment of compensation, and the Participant shall pay any Forfeiture Amount required by Section 15(j) of the Incentive Plan, or any other amount as required by the terms of any such policy or applicable law.

ATI Inc.

By:

Name: Elliot S. Davis

Title: Senior Vice President, Chief Legal and Compliance Officer

“Disability” shall mean (a) prior to a Change in Control, any condition as a result of which the Participant has been determined eligible to receive long-term disability benefits under the Company’s long term disability plan and (b) following a Change in Control, as defined in any change in control, salary continuation or similar agreement between the Participant and the Company or any of its Subsidiaries or Affiliates.

“Good Reason” means, without the Participant’s express written consent, the occurrence of any one or more of the following:

(1) (i) a material diminution of the Participant’s position, authorities, duties, responsibilities or status (including offices, titles, or reporting relationships) as an employee of the Company (or those of the supervisor to whom the Participant is required to report, including a requirement that the Participant report to a corporate officer or other employee rather than directly to the Board), in each case, from those in effect as of immediately prior to the Change in Control, or (ii) the assignment to the Participant of duties or responsibilities inconsistent with his or her position as of immediately prior to the Change in Control, other than an insubstantial and inadvertent act that is remedied by the Company promptly after receipt of notice thereof given by the Participant;

(2) the Company’s requiring the Participant to be based at a location in excess of thirty-five (35) miles from the location of the Participant’s principal job location or office immediately prior to the Change in Control, except for required travel on the Company’s business to an extent consistent in all material respects with the Participant’s business travel obligations as of immediately prior to the Change in Control;

(3) (i) a reduction in the Participant’s annual base salary, (ii) a material reduction in the Participant’s target annual incentive opportunity or (iii) a material reduction in the other compensation and benefits provided or made available to the Participant from the Company, in each case, from those in effect immediately prior to the Change in Control or, if greater, following the Change in Control;

(4) a material breach of any Change in Control severance or similar agreement in place between the Company and the Participant, including the failure of the Company to obtain an unqualified agreement from any successor to the Company to assume and agree to perform the Company’s obligations under any such agreement;

(5) a material diminution in the budget over which the Participant retains authority relative to such budget immediately prior to the Change in Control; or

(6) any purported attempt by the Company to terminate the Participant’s employment other than for Cause or by reason of Disability occurring after an event constituting Good Reason.

The Participant’s mental or physical incapacity following the occurrence of an event described above shall not affect his or her ability to terminate employment for Good Reason, and the Participant’s death following delivery of a notice of termination for Good Reason shall not affect

the Participant’s estate’s entitlement to benefits provided upon a termination of employment for Good Reason.

To invoke a termination for Good Reason, the Participant must provide written notice to the Company of the existence of one or more of the conditions described above within ninety (90) days following the Participant’s knowledge of the initial existence of such condition or conditions, specifying in reasonable detail the conditions constituting Good Reason, and the Company or its affiliate will have thirty (30) days following receipt of such written notice (the “Cure Period”) during which it may remedy the condition. If the Company or the affiliate fails to remedy the condition constituting Good Reason during the applicable Cure Period, the Participant’s Termination of Service must occur, if at all, within thirty (30) days following such Cure Period.

“Retirement” shall mean, (a) prior to a Change in Control, a termination of employment with the Company and each Subsidiary of the Company, with the consent of the Company at or after (i) attaining age 55 and (ii) completing five years of employment with the Company or any Subsidiary of the Company and (b) following a Change in Control, at or after (i) attaining age 55 and (ii) completing five (5) years of employment with the Company or any Subsidiary of the Company.

The table below provides actions or adjustments for various events that might impact either the Company or any of the TSR peer companies.