AVIENT CORP

Reconciliation of Non-GAAP Financial Measures (Unaudited)

(Dollars in millions, except per share data)

Senior management uses comparisons of diluted adjusted earnings per share (EPS) from continuing operations attributable to Avient shareholders, excluding special items, to assess performance and facilitate comparability of results. Senior management also uses adjusted operating income to assess performance and allocate resources because senior management believes that this measure is useful in understanding current profitability levels and how it may serve as a basis for future performance. In addition, adjusted operating income is a component of Avient’s annual employee incentive plans and is used in debt covenant computations.

Further, as a result of Avient's portfolio shift to an innovator of materials solutions, it has completed several acquisitions and divestitures, which have resulted in a significant amount of intangible asset amortization. Management excludes intangible asset amortization from adjusted EPS as it believes excluding acquired intangible asset amortization is a useful measure of current period earnings per share.

Senior management believes the measures described above are useful to investors because they allow for comparison to Avient's performance in prior periods without the effect of items that, by their nature, tend to obscure Avient's operating results due to the potential variability across periods based on timing, frequency and magnitude. The presentation of these non-GAAP measures is not intended to be considered in isolation from, as a substitute for, or as superior to, the financial information prepared and presented in accordance with U.S. GAAP. Non-GAAP financial measures have limitations as analytical tools and should not be considered in isolation from, or solely as alternatives to, financial measures prepared in accordance with GAAP. The presentation of these measures may be different from non-GAAP financial measures used by other companies.

A reconciliation of these measures to their most directly comparable GAAP measures is provided in the tables below.

(1) Special items include charges related to specific strategic initiatives or financial restructuring such as: consolidation of operations; debt extinguishment costs; costs incurred directly in relation to acquisitions or divestitures; employee separation costs resulting from personnel reduction programs, plant realignment costs, executive separation agreements; asset impairments; settlement gains or losses and mark-to-market adjustments associated with actuarial gains and losses on pension and other post-retirement benefit plans; environmental remediation costs, fines, penalties and related insurance recoveries related to facilities no longer owned or closed in prior years; gains and losses on the divestiture of operating businesses, joint ventures and equity investments; gains and losses on facility or property sales or disposals; results of litigation, fines or penalties, where such litigation (or action relating to the fines or penalties) arose prior to the commencement of the performance period; one-time, non-recurring items; and the effect of changes in accounting principles or other such laws or provisions affecting reported results. The tax benefit or expense on the foregoing special items, non-recurring income tax items and adjustments to uncertain tax position reserves and deferred income tax valuation allowances are also included.

Appendix A 80

Appendix A 81

Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: KEEP THIS PORTION FOR YOUR RECORDS DETACH AND RETURN THIS PORTION ONLYTHIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. V69480-P25455 ! ! ! For All Withhold All For All Except For Against Abstain ! !! ! !! To withhold authority to vote for any individual nominee(s), mark "For All Except" and write the number(s) of the nominee(s) on the line below. 2. Approval, on an advisory basis, of Named Executive Officer compensation. 3. Ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2025. THIS PROXY AND VOTING INSTRUCTION CARD, WHEN PROPERLY EXECUTED, WILL BE VOTED AS DIRECTED OR, IF NO DIRECTION IS GIVEN, WILL BE VOTED AS THE BOARD RECOMMENDS. 1. Election of twelve director nominees to our Board of Directors. The Board of Directors recommends you vote FOR ALL nominees listed in Proposal 1 and FOR Proposals 2 and 3. AVIENT CORPORATION Nominees: 01) Robert E. Abernathy 02) Richard H. Fearon 03) Gregory J. Goff 04) Neil Green 05) William R. Jellison 06) Ashish K. Khandpur 07) Sandra Beach Lin 08) Kim Ann Mink 09) Ernest Nicolas 10) Kerry J. Preete 11) Patricia Verduin 12) William A. Wulfsohn Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor, administrator, or other fiduciary, please give full title as such. Joint owners should each sign personally. All holders must sign. If a corporation or partnership, please sign in full corporate or partnership name by authorized officer. SCAN TO VIEW MATERIALS & VOTEw AVIENT CORPORATION 33587 WALKER ROAD AVON LAKE, OH 44012 VOTE BY INTERNET Before The Meeting - Go to www.proxyvote.com or scan the QR Barcode above Use the Internet to transmit your voting instructions and for electronic delivery of information up until 11:59 P.M. Eastern Time on May 13, 2025, or up until 11:59 P.M. Eastern Time on May 12, 2025 for shares held in the Avient Retirement Savings Plan. Have your proxy and voting instruction card in hand when you access the website and follow the instructions to obtain your records and to create an electronic voting instruction form. During The Meeting - Go to www.virtualshareholdermeeting.com/AVNT2025 You may attend the meeting via the Internet and vote during the meeting. Have the information that is printed in the box marked by the arrow available and follow the instructions. VOTE BY PHONE - 1-800-690-6903 Use any touch-tone telephone to transmit your voting instructions up until 11:59 P.M. Eastern Time on May 13, 2025, or up until 11:59 P.M. Eastern Time on May 12, 2025 for shares held in the Avient Retirement Savings Plan. Have your proxy and voting instruction card in hand when you call and then follow the instructions. VOTE BY MAIL Mark, sign and date your proxy card and return it in the postage-paid envelope we have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717.

V69481-P25455 Avient Corporation 2025 ANNUAL MEETING OF SHAREHOLDERS Wednesday, May 14, 2025 9:00 a.m. Eastern Time Virtually via live webcast at www.virtualshareholdermeeting.com/AVNT2025 Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting: The Notice, Proxy Statement, Proxy Card, and Annual Report are available at www.proxyvote.com. AVIENT CORPORATION This proxy and voting instruction card is solicited by the Board of Directors for use at and in connection with the Annual Meeting of Shareholders to be held on May 14, 2025. The shares of common stock held will be voted as you specify on the reverse side. If no choice is specified, this proxy and voting instruction card will be voted FOR ALL nominees listed in Proposal 1 and FOR Proposals 2 and 3. By signing this proxy and voting instruction card, you revoke all prior proxies and appoint Amy M. Sanders, Jamie A. Beggs, and Kristen A. Gajewski, and each of them, with full power of substitution, to vote the common shares of Avient Corporation, held of record on March 18, 2025, on the matters shown on the reverse side hereof and on any other matters that may come before the Annual Meeting of Shareholders and all adjournments or postponements. IMPORTANT NOTICE TO PARTICIPANTS IN THE AVIENT RETIREMENT SAVINGS PLAN: As a participant under the Avient Retirement Savings Plan (the "Plan"), Fidelity Management Trust Company, as Trustee of the Plan, has been requested to forward you important information concerning your rights as a participant in the Plan. The number of common shares you are eligible to direct the Trustee to vote is based on your balance in the Plan (based on your balance in the Avient Stock Fund) on March 18, 2025, the record date for the determination of shareholders eligible to vote at the Annual Meeting of Shareholders to be held on May 14, 2025. We encourage you to exercise your rights under the Plan. Please review the enclosed documents carefully before deciding how to direct the Trustee. Because the common shares in the Plan are registered in the name of the Trustee, you will not be able to direct the common shares attributable to your interest in the Plan electronically online during the Annual Meeting of Shareholders. To give a proper direction, you must vote by returning this completed proxy and voting instruction card, signed and dated, in the enclosed envelope or by following telephone or internet voting procedures set forth in this proxy and voting instruction card. Directions must be received by May 12, 2025. If you give a proper direction, the Trustee will vote the common shares attributable to your interest in the Plan as you direct, unless otherwise required by law. If you do not give a proper direction, the Trustee will vote the common shares attributable to your interest in the same proportion as the proper directions that the Trustee does receive, unless otherwise required by law. Directions received after May 12, 2025 will not be counted for common shares held in the Plan. Your direction to the Trustee is confidential and will not be disclosed unless required by law. As a participant under the Avient Retirement Savings Plan, I hereby direct Fidelity Management Trust Company as Trustee of the Avient Retirement Savings Plan to vote (electronically online during the Annual Meeting of Shareholders or by proxy), as designated on the reverse side, the whole number of common shares of Avient Corporation that are held by the Trustee and attributable to my interest in the Plan on March 18, 2025, and also a proportionate number of shares as of such date to which no directions have been received, at the Annual Meeting of Shareholders to be held on May 14, 2025. Address changes and comments can be directed to Avient's Investor Relations Department at investorrelations@avient.com See reverse for voting instructions.