You are cordially invited to attend the 2023 Annual Meeting of Stockholders of ATI Physical Therapy, Inc., to be held virtually at www.virtualshareholdermeeting.com/ATIP2023 on June 13, 2023 at 10:00 a.m. Central Time. The Annual Meeting will be held in a virtual meeting format only and you will not be able to attend in person. Instructions for accessing the virtual meeting platform online are included in the proxy statement for this meeting.

The matters expected to be acted upon at the Annual Meeting are described in the accompanying Notice of Annual Meeting of Stockholders and proxy statement. The Annual Meeting materials include the notice, proxy statement, our annual report, and proxy card.

Your vote is important. Whether or not you plan to attend the Annual Meeting virtually, please cast your vote as soon as possible by Internet, telephone or, if you received a paper proxy card and voting instructions by mail, by completing and returning the enclosed proxy card in the postage-prepaid envelope to ensure that your shares will be represented. Your vote by written proxy will ensure your representation at the Annual Meeting regardless of whether you are able to attend virtually. Returning the proxy does not affect your right to attend the Annual Meeting virtually or to vote your shares virtually during the Annual Meeting.

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING TO BE HELD ON JUNE 13, 2023. THE PROXY STATEMENT AND ANNUAL REPORT ARE AVAILABLE AT www.virtualshareholdermeeting.com/ATIP2023.

WHETHER OR NOT YOU PLAN TO ATTEND THE VIRTUAL ANNUAL MEETING, WE ENCOURAGE YOU TO VOTE AND SUBMIT YOUR PROXY THROUGH THE INTERNET OR BY TELEPHONE OR REQUEST AND SUBMIT YOUR PROXY CARD AS SOON AS POSSIBLE, SO THAT YOUR SHARES MAY BE REPRESENTED AT THE MEETING.

The accompanying proxy is solicited on behalf of the board of directors (“Board of Directors” or “Board”) of ATI Physical Therapy, Inc. for use at our 2023 Annual Meeting of Stockholders, or Annual Meeting, to be held virtually at www.virtualshareholdermeeting.com/ATI2023 on June 13, 2023 at 10:00 a.m. Central Time, and any adjournment or postponement thereof. The Notice of Internet Availability of Proxy Materials and this proxy statement for the Annual Meeting, or Proxy Statement, and the accompanying form of proxy were first distributed and made available on the Internet to stockholders on or about May   , 2023. An annual report for the fiscal year ended December 31, 2022 is available with this Proxy Statement by following the instructions in the Notice of Internet Availability of Proxy Materials. In this Proxy Statement, we refer to ATI Physical Therapy, Inc. as “ATI,” the “Company,” “we,” or “us.” References to our website in this Proxy Statement are not intended to function as hyperlinks and the information contained on our website is not intended to be incorporated into this Proxy Statement.

In accordance with U.S. Securities and Exchange Commission (the “SEC”) rules, we are using the Internet as our primary means of furnishing proxy materials to stockholders. Consequently, most stockholders will not receive paper copies of our proxy materials. We will instead send these stockholders a Notice of Internet Availability of Proxy Materials with instructions for accessing the proxy materials, including our Proxy Statement and annual report, and voting via the Internet. The Notice of Internet Availability of Proxy Materials also provides information on how stockholders may obtain paper copies of our proxy materials if they so choose. We believe this rule makes the proxy distribution process more efficient, less costly, and helps in conserving natural resources.

You are receiving this Proxy Statement because our Board of Directors is soliciting your proxy to vote your shares at the Annual Meeting with respect to the proposals described in this Proxy Statement. This Proxy Statement includes information that we are required to provide to you pursuant to the rules and regulations of the SEC and is designed to assist you in voting your shares.

Only holders of record of our Class A common stock (“Common Stock”) at the close of business on April  , 2023, or the Record Date, will be entitled to vote at the Annual Meeting. At the close of business on the Record Date, we had [   ] shares of Common Stock outstanding and entitled to vote. For ten days prior to the Annual Meeting, a complete list of the stockholders entitled to vote at the Annual Meeting will be available for examination by any stockholder for any purpose relating to the Annual Meeting during ordinary business hours at our headquarters, at 790 Remington Blvd., Bolingbrook, Illinois 60440. If our headquarters are closed during the ten days prior to the Annual Meeting, a stockholder may send a written request to our Chief Legal Officer and Corporate Secretary at 790 Remington Blvd., Bolingbrook, Illinois 60440, and we will arrange a way for the stockholder to inspect the list.

The holders of shares of outstanding capital stock of the Company representing a majority of the voting power of all outstanding shares of capital stock of the Company entitled to vote at such meeting as of the Record Date must be present, in person or by proxy, at the Annual Meeting in order to conduct business. This presence is called a quorum. Proxies received but marked as abstentions, if any, and broker non-votes (as described below) will be included in the calculation of the number of shares considered to be present at the meeting for quorum purposes.

In deciding all matters at the Annual Meeting, as of the close of business on the Record Date, each share of Common Stock represents one vote. We do not have cumulative voting rights for the election of directors. You may vote all shares owned by you as of the Record Date, including (i) shares held directly in your name as the stockholder of record and (ii) shares held for you as the beneficial owner in street name through a broker, bank, trustee, or other nominee.

Stockholder of Record: Shares Registered in Your Name. If, on the Record Date, your shares were registered directly in your name with our transfer agent, Continental Stock Transfer & Trust Company then you are considered the stockholder of record with respect to those shares. As a stockholder of record, you may vote at the Annual Meeting or vote by telephone, through the Internet or, if you request or receive paper proxy materials, by filling out and returning the proxy card.

Beneficial Owner: Shares Registered in the Name of a Broker or Nominee. If, on the Record Date, your shares were held in an account with a brokerage firm, bank, or other nominee, then you are the beneficial owner of the shares held in street name. As a beneficial owner, you have the right to direct your nominee on how to vote the shares held in your account, and your nominee has enclosed or provided voting instructions for you to use in directing it on how to vote your shares. However, the organization that holds your shares is considered the stockholder of record for purposes of voting at the Annual Meeting. Because you are not the stockholder of record, you may not vote your shares at the Annual Meeting unless you request and obtain a valid proxy from the organization that holds your shares giving you the right to vote the shares at the Annual Meeting.

For Proposals No. 4-A and 4-B, each director will be elected by a plurality of the votes cast by the stockholders present in person or represented by proxy at the meeting and entitled to vote thereon, which means that the four individuals nominated for election to our Board of Directors at the Annual Meeting receiving the highest number of “FOR” votes will be elected. For Proposals No. 1, 3, 5, 6 and 7, approval will require the affirmative vote of a majority of the votes cast by the stockholders present in person or represented by proxy at the meeting and entitled to vote thereon. The affirmative vote of the holders of at least 66.7% of the outstanding shares of our Common Stock entitled to vote is required to approve Proposal 2, the Declassification Proposal.

Under Delaware law, abstentions are counted as present and entitled to vote for purposes of determining whether a quorum is present. Abstentions are not considered “votes cast” and therefore will have no effect on Proposals No. 1, 2, 3, 5, 6 and 7. At the Annual Meeting, there will be no abstentions on Proposals No. 4-A and 4-B. Rather, stockholders will have the option to “withhold” their vote for all or any of the Class II directors up for election.

Broker non-votes occur when shares held by a broker for a beneficial owner are not voted because the broker did not receive voting instructions from the beneficial owner and lacked discretionary authority to vote the shares. Under Delaware law, broker non-votes are counted as present and entitled to vote for purposes of determining whether a quorum is present. However, brokers have limited discretionary authority to vote shares that are beneficially owned. While a broker is entitled to vote shares held for a beneficial owner on “routine” matters without instructions from the beneficial owner of those shares, absent instructions from the beneficial owner of such shares, a broker is not entitled to vote shares held for a beneficial owner on “non-routine” matters. At our Annual Meeting, only Proposal No. 3 is considered a routine matter for which brokers have discretionary authority to vote shares that are beneficially owned. There will therefore be no broker non-votes on Proposal 3. The other proposals presented at the Annual Meeting are non-routine matters for which broker non-votes are not deemed to be “votes cast”. Broker non-votes will therefore have no effect on Proposals No. 1, 2, 4, 5, 6 and 7.

Votes submitted by telephone or through the Internet must be received by 11:59 p.m. Eastern Time on June 12, 2023. Submitting your proxy, whether by telephone, through the Internet or, if you request or receive a paper proxy card, by mail will not affect your right to vote at the Annual Meeting should you decide to attend the Annual Meeting virtually. If you are not the stockholder of record, please refer to the voting instructions provided by your nominee to direct your nominee on how to vote your shares. Your vote is important. Whether or not you plan to attend the Annual Meeting, we urge you to vote by proxy to ensure that your vote is counted.

All proxies will be voted in accordance with the instructions specified on the proxy card. If you sign a physical proxy card and return it without instructions as to how your shares should be voted on a particular proposal at the Annual Meeting, your shares will be voted in accordance with the recommendations of our Board of Directors stated above.

If you do not vote and you hold your shares in street name, and your broker does not have discretionary power to vote your shares, your shares may constitute “broker non-votes” (as described above) and will not be counted in determining the number of shares necessary for approval of the proposals, except for Proposal 3. However, broker non-votes will be counted for the purpose of establishing a quorum for the Annual Meeting.

If you receive more than one proxy card, your shares are registered in more than one name or are registered in different accounts. To make certain all of your shares are voted, please follow the instructions included on each proxy card and vote each proxy card by telephone, through the Internet, or by mail. If you requested or received paper proxy materials and you intend to vote by mail, please complete, sign, and return each proxy card you received to ensure that all of your shares are voted.

We recommend that you vote your shares in advance of the meeting as instructed above, even if you plan to attend the Annual Meeting virtually.

A stockholder of record who has given a proxy may revoke it at any time before it is exercised at the Annual Meeting by:

Please note, however, that if your shares are held of record by a broker, bank, or other nominee and you wish to revoke a proxy, you must contact that firm to revoke any prior voting instructions.

We will pay the expenses of soliciting proxies, including preparation, assembly, printing, and mailing of this Proxy Statement, the proxy, and any other information furnished to stockholders. Following the original mailing of the soliciting materials, we and our agents, including directors, officers, and other employees, without additional compensation, may solicit proxies by mail, email, telephone, facsimile, by other similar means, or in person. Following the original mailing of the soliciting materials, we will request brokers, custodians, nominees, and other record holders to forward copies of the soliciting materials to persons for whom they hold shares and to request authority for the exercise of proxies. In such cases, we, upon the request of the record holders, will reimburse such holders for their reasonable expenses. If you choose to access the proxy materials or vote through the Internet, you are responsible for any Internet access charges you may incur.

Voting results will be tabulated and certified by the inspector of elections appointed for the Annual Meeting. The preliminary voting results will be announced at the Annual Meeting. The final results will be tallied by the inspector of elections and filed with the SEC in a current report on Form 8-K within four business days after the Annual Meeting.

Our current Board of Directors consists of nine (9) members:

In accordance with our Second Amended and Restated Certificate of Incorporation (“Charter”), we have a classified Board of Directors, which divides our Board into three classes with staggered three-year terms, with only one class of directors being elected in each year.

At each succeeding annual meeting of the stockholders, successors to the class of directors whose term expires at that annual meeting shall be elected for a three-year term or until the election and qualification of their respective successors in office, subject to their earlier death, resignation or removal.

As further described in Proposals 1 and 2, if the Transaction Proposal and Declassification Proposal are approved, the phase out of our classified Board structure will commence at the Annual Meeting, at which the current Class II directors will be nominated for election for a one year term. At the 2024 annual meeting of stockholders, any directors elected at the 2023 meeting along with our Class III directors, together with any directors appointed to fill vacancies or newly created directorships, will stand for election for a one year term. At our 2025 annual meeting of stockholders, all directors will be nominated for election for a one-year term. The phasing in of annual elections of directors over this period is designed so that the term of any incumbent director will not be shortened, and to ensure a smooth transition to annual elections of all our directors over time.

In addition, as part of the comprehensive transaction to enhance the Company’s liquidity further described in the Transaction Proposal (the “Transaction”), we have agreed to certain corporate governance changes. Among other things, contingent on approval of the Transaction Proposal and the closing of the Transaction, (i) Mr. Maldonado, a Class II director who is affiliated with Advent and is nominated for election at this Annual Meeting, will resign from the Board upon the closing of the Transaction and (ii) our preferred equityholders will have the right to appoint three additional directors to our Board (resulting in the right of the preferred equityholders to appoint a total of four directors to the Board). We anticipate that the preferred equityholders will appoint such directors in connection with the closing of the Transaction, which we anticipate will take place promptly after this Annual Meeting. As further described in the Declassification Proposal, any new preferred equityholder directors will not be included in our Board classes, rather, their terms will expire at the 2024 annual meeting of stockholders.

The Board has determined that each of Ms. Burns, Mr. Dourney, Mr. Maldonado, Mr. McKnight, Mr. Parisi, Mr. Petrone, and Ms. Sparks are independent directors under applicable NYSE rules for purposes of serving on our Board.

Our Board of Directors has primary responsibility for the oversight of our risk management while management is responsible for day-to-day management of risk. The Board oversees risk management either as a whole or through Board committees, discusses with management our major risk exposures, their potential impact on our business and the steps we take to manage them. This risk oversight process includes the Audit Committee of the Board of Directors (i) identifying major risk areas and (ii) presenting such exposure to the Board of Directors to assess our risk identification, risk management and mitigation strategies with respect to areas of potential material risk, including strategic, operational, legal, compliance, human resources, financial, cybersecurity, strategic, and reputational risk. The risk oversight process also includes the Compensation Committee’s oversight of the management of risks relating to our compensation plans and arrangements, including whether the Company’s incentive compensation plans encourage excessive or inappropriate risk taking, and the Nominating and Corporate Governance Committee’s oversight of governance practices and the composition of our Board and its committees.

At each meeting of the Audit Committee of our Board of Directors our management reports on existing and emerging risks at our Company, including, as appropriate, risk assessments, cyber and data security risks, privacy updates and any security incidents. The Company’s executive management team also meets regularly to discuss cyber and data security risks.

On June 16, 2021 (the “Closing Date”), a Business Combination transaction (the “Business Combination”) was finalized pursuant to the Agreement and Plan of Merger (“Merger Agreement”), dated February 21, 2021 between the operating company, Wilco Holdco, Inc. (“Wilco Holdco”), and Fortress Value Acquisition Corp. II ( “FAII” or “FVAC”), a special purpose acquisition company. In connection with the closing of the Business Combination, the Company changed its name from Fortress Value Acquisition Corp. II to ATI Physical Therapy, Inc. The Business Combination was accounted for as a reverse recapitalization in accordance with U.S. generally accepted accounting principles. The Company’s Common Stock is listed on the NYSE under the symbol “ATIP.”

In connection with the execution of the Merger Agreement, FAII entered into the Stockholders Agreement with certain entities affiliated with Advent party thereto, (the “Advent Stockholders”) which became effective upon the Closing Date. Pursuant to the terms of the Stockholders Agreement, the Advent Stockholders currently have the right to designate director nominees for election to the Board at any meeting of our stockholders (“Advent Directors”). The number of nominees that the Advent Stockholders are entitled to nominate pursuant to the Stockholders Agreement is dependent on the aggregate number of shares of our Common Stock (including any securities or rights convertible into, or exercisable or exchangeable for (in each case, directly or indirectly), shares of our Common Stock, including options and warrants) held by Advent Stockholders. For so long as the Advent Stockholders own (i) 50% or more of our Common Stock, the Advent Stockholders are entitled to designate five (5) Advent Directors, (ii) 38% or more (but less than 50%) of our Common Stock, the Advent Stockholders are entitled to designate four (4) Advent Directors, (iii) 26% or more (but less than 38%) of our Common Stock, the Advent Stockholders are entitled to designate three (3) Advent Directors, (iv) 13% or more (but less than 26%) of our Common Stock, the Advent Stockholders are entitled to designate two (2) Advent Directors, (v) 5% or more (but less than 13%) of our Common Stock, the Advent Stockholders are entitled to designate one (1) Advent Director and (vi) less than 5%, the Advent Stockholders are not entitled to designate any Advent Directors.

In addition, in connection with our recent refinancing, on February 24, 2022 (the “Refinancing Date”), we issued, in the aggregate, 165,000 shares of non-convertible Series A Senior Preferred Stock with an initial stated value of $1,000 per share, or $165.0 million of stated value in the aggregate (“Series A Preferred Stock”), which includes warrants to purchase up to 11.5 million shares of Common Stock. The holders of Series A Preferred Stock, voting as a separate class, have the right to designate and elect one director to serve on the Company’s Board until such time that (i) as of any applicable fiscal quarter end, the Company’s 12-month Consolidated Adjusted EBITDA (as defined in the Certificate of Designation for the Series A Preferred Stock) exceeds $100,000,000, or (ii) the Lead Purchaser (as defined in the Certificate of Designation for the Series A Preferred Stock) ceases to hold at least 50.1% of the Series A Preferred Stock originally held by it. The holders of Series A Preferred Stock designated Daniel Dourney as their designee, and the Board appointed Mr. Dourney to the Board on February 24, 2022.

In connection with the Transaction and contingent on approval of the Transaction Proposal and closing of the Transaction, among other things, (i) our Stockholders Agreement with the Advent Stockholders will be terminated and Advent will no longer have the right to designate director nominees for election to our Board and (ii) our preferred equityholders will have the right to appoint three additional directors to our Board (resulting in the right of the preferred equityholders to appoint a total of four directors to the Board).

Because Advent currently beneficially owns a majority of the voting power of our outstanding Common Stock, we are a “controlled company” under the listing rules of the NYSE. As a controlled company, we are exempt from certain NYSE governance requirements that would otherwise apply to the composition and function of our Board. For example, we are not required to comply with certain rules that would otherwise require, among other things, (i) the compensation of our executive officers to be determined by a majority of the independent directors or a committee of independent directors, and (ii) director nominees to be selected or recommended either by a majority of the independent directors or a committee of independent directors. Notwithstanding our status as a controlled company, we remain subject to the requirements that our independent directors hold regular executive sessions and that our Audit Committee consist entirely of independent directors.

If at any time we cease to be a controlled company, we will take all action necessary to comply with the NYSE listing rules, including ensuring that our Compensation Committee and our Nominating and Corporate Governance Committee are each composed entirely of independent directors, subject to any permitted “phase-in” periods. We will no longer qualify as a controlled company once a majority of the voting power of our outstanding Common Stock is no longer held by a single person, entity or group.

In connection with the Transaction and contingent on approval of the Transaction Proposal and closing of the Transaction, we anticipate that funds affiliated with Knighthead Capital Management, LLC, who are the current holders of our Series A Senior Preferred Stock, will gain a majority of the voting power of our outstanding Common Stock, resulting in a change of control of the Company under NYSE listing rules. We will, however, remain a “controlled company” under the listing rules of the NYSE.

Any nominee for director in an uncontested election who fails to receive a majority of the votes cast at a stockholder meeting must tender their resignation to the Board from the Board and all committees thereof. A director nominee shall have failed to receive the affirmative vote of a majority of votes cast if the number of “against” votes in respect of such director nominee’s election exceeds the number of votes “for” such director nominee’s election (excluding abstentions and broker non-votes). The Nominating and Corporate Governance Committee shall assess the appropriateness of such nominee continuing to serve as a director and shall recommend to the Board the action to be taken with respect to such tendered resignation. Any director who tenders a resignation pursuant to this provision shall not participate in the Nominating and Corporate Governance Committee recommendation or Board action regarding whether to accept the resignation offer. In determining whether or not to recommend that the Board accept any resignation offer, the Nominating and Corporate Governance Committee may consider all factors believed relevant by its members. The Board will act on the Nominating and Corporate Governance Committee’s recommendation and publicly disclose its decision and rationale within 90 days from the publication of the election results.

We have four standing committees - an Audit Committee, a Compensation Committee, a Nominating and Corporate Governance Committee and a Healthcare Compliance Committee. The Board may from time to time establish other committees. Each of the committees report to the Board as it deems appropriate and as the Board may request. The composition, duties and responsibilities of these committees are set forth below.

Joanne Burns, James Parisi and Teresa Sparks are members of the Audit Committee. James Parisi is the Chair of the Audit Committee. Each member of the Audit Committee qualifies as an independent director under the NYSE corporate governance standards and the independence requirements of Rule 10A-3 of the Exchange Act. In addition, each of Ms. Burns, Mr. Parisi and Ms. Sparks is an “audit committee financial expert” within the meaning of 407(d) of Regulation S-K promulgated under the Securities Act.

Pursuant to the Stockholders Agreement and subject to the terms therein, as long as there are two or more Advent Directors on the Board, the investors’ party thereto have the right to require that at least a majority of the members of the Audit Committee be Advent Directors. Contingent on approval of the Transaction Proposal and closing of the Transaction, we anticipate that the Stockholders Agreement will be terminated.

Under its charter, the functions of the Audit Committee include:

Joanne Burns, John Larsen and Carmine Petrone are members of the Compensation Committee. Carmine Petrone is Chair of the Compensation Committee. The Board has determined that Ms. Burns and Mr. Petrone are independent under SEC rules for purposes of serving on the Compensation Committee.

Pursuant to the Stockholders Agreement and subject to the terms therein, as long as there are two or more Advent Directors on the Company’s Board, the investors that are party thereto have the right to require at least a majority of the members of the Compensation Committee be Advent Directors. Contingent on approval of the Transaction Proposal and closing of the Transaction, we anticipate that the Stockholders Agreement will be terminated. Under its charter, the functions of the Compensation Committee include:

The Compensation Committee charter also provides that the Compensation Committee shall have the sole authority to retain or obtain the advice of a compensation consultant, legal counsel or other adviser. However, before engaging or receiving advice from a compensation consultant, external legal counsel or any other adviser, the Compensation Committee will consider the independence of each such adviser, including the factors required by the NYSE and the SEC.

Currently, John Larsen, John Maldonado and James Parisi are members of the Nominating and Corporate Governance Committee. John Larsen is Chair of the Nominating and Corporate Governance Committee.

Pursuant to the Stockholders Agreement and subject to the terms therein, as long as there are two or more Advent Directors on the Board, the investors’ party thereto have the right to require at least a majority of the members of the Nominating and Corporate Governance Committee be Advent Directors. Contingent on approval of the Transaction Proposal and closing of the Transaction, we anticipate that the Stockholders Agreement will be terminated.

On February 21, 2023, the Board approved an amendment to the Nominating and Corporate Governance Committee Charter to delegate oversight of Environmental, Social and Corporate Governance (“ESG”) to the Nominating and Corporate Governance Committee. Under its charter, the functions of the Nominating and Corporate Governance Committee include:

The Nominating and Corporate Governance Committee shall have the sole authority to retain and terminate any search firm to be used to identify director candidates and shall have sole authority to approve the search firm’s fees and other retention terms.

Currently, John Maldonado, Teresa Sparks and Andrew McKnight are members of the Health Care Compliance Committee. Teresa Sparks is Chair of the Health Care Compliance Committee.

Under its charter, the functions of the Health Care Compliance Committee include:

Our Board of Directors and its committees meet regularly throughout the year, and also hold special meetings and act by written consent from time to time. During fiscal year 2022, our Board of Directors met 8 times, the Audit Committee met 9 times, the Compensation Committee met 4 times and the Nominating and Corporate Governance Committee met 4 times. During fiscal year 2022, each member of our Board of Directors attended at least 75% of the aggregate of all meetings of our Board of Directors and of all meetings of committees of our Board of Directors on which such member served that were held during the period in which such director served.

Our policy is to invite and encourage each member of our Board of Directors to be present at our annual meetings of stockholders. We completed our Business Combination and became a public company on June 17, 2021 and this 2023 Annual Meeting is our second annual meeting.

Stockholders and interested parties who wish to communicate with our Board of Directors, non-management members of our Board of Directors as a group, a committee of our Board of Directors, or a specific member of our Board of Directors (including our chairperson or lead independent director, if any) may do so by letters addressed to the attention of our Chief Legal Officer and Corporate Secretary.

All communications are reviewed by the Chief Legal Officer and Corporate Secretary and provided to the members of our Board of Directors as appropriate. Unsolicited items, sales materials, abusive, threatening, or otherwise inappropriate materials, and other routine items and items unrelated to the duties and responsibilities of our Board of Directors will not be provided to directors.

The address for these communications is:

ATI has adopted a Code of Conduct & Compliance Program Guide applicable to its directors, executive officers and employees, including its principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions that complies with the rules and regulations of the NYSE. A copy of the Code of Conduct & Compliance Program Guide will be provided without charge upon written request to Erik Kantz, Chief Legal Officer and Corporate Secretary, in writing at our principal executive offices at 790 Remington Boulevard, Bolingbrook, Illinois 60440 and a copy can be found on our investor relations website at https://investors.atipt.com under the link “Governance Documents.” We intend to satisfy any disclosure requirements related to waivers of or amendments to our Code of Conduct & Compliance Program Guide by posting such information on our website at www.investors.atipt.com.

Our culture is shaped by our core values, which are as follows:

As part of our core value of “teamwork,” we support various initiatives. We strive to ensure our work environment reflects diversity, fairness and meritocracy. We strive to provide a voice for our diverse employees to share insights, communicate with leadership, and generate ideas and actions to enhance and impact diversity at the Company. We also offer our local communities the benefits of a large corporate network, while delivering services and support with a local focus. In the communities we serve, ATI is elevating awareness of health and wellness. We assist children and families in need through our support of the ATI Foundation, a 501(c)(3) charity organized to provide funding to children with physical impairments.

Candidates for nomination to our Board of Directors are selected by our Board of Directors based on the recommendation of the Nominating and Corporate Governance Committee in accordance with the Committee’s charter, our Charter and amended and restated bylaws (“Bylaws”). The Nominating and Corporate Governance Committee is responsible for identifying, screening and recommending candidates to the entire Board of Directors for membership. In recommending candidates for nomination, the Nominating and Corporate Governance Committee considers candidates recommended by directors, officers, employees, stockholders, and others. Evaluations of candidates generally involve a review of background materials, internal discussions, and interviews with selected candidates as appropriate and, in addition, the committee may engage consultants or third-party search firms to assist in identifying and evaluating potential nominees.

At the time of the consummation of our Business Combination on June 17, 2021, John Larsen, John Maldonado, Carmine Petrone, Christopher Krubert, Joanne Burns, James Parisi and Andrew McKnight were nominated for election to the Board of Directors. Teresa Sparks was appointed to the Board of Directors on December 8, 2021. Christopher Krubert resigned and Daniel Dourney, pursuant to nomination rights of the holders of our Series A Preferred Stock (as discussed above), was appointed to the Board of Directors on February 24, 2022. As described further in this Proxy Statement, our Board of Directors has nominated Joanne Burns, John Maldonado, James Parisi and Sharon Vitti for re-election at the 2023 Annual Meeting.

Additional information regarding the process for properly submitting stockholder nominations for candidates for membership on our Board of Directors is set forth below under “Additional Information—Stockholder Proposals to Be Presented at Next Annual Meeting.”

The Nominating and Corporate Governance Committee is responsible for reviewing with the Board of Directors, on an annual basis, the appropriate characteristics, skills and experience required for the Board of Directors as a whole and its individual members. In evaluating the suitability of individual candidates (both new candidates and current members of the Board of Directors), the Nominating and Corporate Governance Committee, in recommending candidates for election, and the Board of Directors, in approving (and, in the case of vacancies, appointing) such candidates, take into account many factors, including ability to make independent analytical inquiries, general understanding of marketing, finance and other elements relevant to the success of a publicly traded company in today’s business environment, experience in the Company’s industry and with relevant social policy concerns, understanding of the Company’s business on a technical level, other board service and educational and professional background. Each candidate nominee must also possess fundamental qualities of intelligence, honesty, good judgment, high ethics and standards of integrity, fairness and responsibility. The Board of Directors evaluates each individual in the context of the Board of Directors as a whole, with the objective of assembling a group that can best perpetuate the success of the business and represent stockholder interests through the exercise of sound judgment using its diversity of experience in these various areas. In determining whether to recommend a director for re-election, the Nominating and Corporate Governance Committee also considers the director’s past attendance at meetings and participation in and contributions to the activities of the Board of Directors. The Nominating and Corporate Governance Committee and the Board of Directors will take into account the nature of and time involved in a director’s service on other boards and/or committees in evaluating the suitability of individual director candidates and current directors and making its recommendations to the Company’s stockholders.

Both the Board and the Nominating and Corporate Governance Committee believe that Board diversity is important to ensure a balanced Board with a rounded perspective. Diversity is broadly interpreted by the Board to include viewpoints, background, experience, industry knowledge and geography, as well as more traditional characteristics of diversity, such as race and gender. Our Nominating and Corporate Governance Committee may also consider such other factors as it may deem, from time to time, to be in our Company’s and stockholders’ best interests.

On April 17, 2023, as further described in the Company’s Form 8-K filed with the SEC on [•], the Company entered into Amendment No. 2 (the “Credit Agreement Amendment”) to the Company’s Credit Agreement, dated as of February 24, 2022, by and among ATI Holdings Acquisition, Inc. as borrower, Wilco Intermediate Holdings, Inc., Barclays Bank PLC, as administrative agent and issuing bank, and the lenders party thereto (the “2022 Credit Agreement” and together with the Credit Agreement Amendment, the “Credit Agreement”), a Note Purchase Agreement, an Assignment and Assumption Agreement, certain other definitive agreements (such documents referred to collectively as the “Signing Date Definitive Documents”), and an Amended & Restated Transaction Support Agreement (the “A&R TSA”), pursuant to which the Parties (as defined below) agreed to and appended thereto final forms of the remaining definitive documents (such documents, the “Closing Date Definitive Documents” and together with the Signing Date Definitive Documents, the “Definitive Documents”), with certain of its first lien lenders under the 2022 Credit Agreement (the “First Lien Lenders”), the administrative agent under the 2022 Credit Agreement, holders of its Series A Senior Preferred Stock (the “Preferred Equityholders”) and holders of the majority of the Company’s Common Stock (together with the First Lien Lenders and the Preferred Equityholders, the “Parties”) setting forth the terms of a comprehensive transaction to enhance the Company’s liquidity (collectively, the “Transaction”). Specifically, the Company has agreed, subject to stockholder approval of this Transaction Proposal, to a delayed draw new money financing in which the Company (i) may cause to be issued to the purchasers from time to time party to the Note Purchase Agreement an aggregate principal amount of $25.0 million (the “Delayed Draw Amounts”) in the form of a new stapled security, comprised of (A) second lien PIK convertible notes (the “Notes”) and (B) shares of Series B Preferred Stock which will provide the holder thereof with voting rights such that the holders thereof will have the right to vote on corporate matters on an as-converted basis as if the conversion occurred at an initial price per share equal to the average closing price for the five trading days immediately preceding the signing of the Note Purchase Agreement (the “NYSE Minimum Price”), (ii) will facilitate the exchange of $100.0 million of the aggregate principal amount of the term loans under the 2022 Credit Agreement held by certain of the Preferred Equityholders for Notes and (iii) will agree to certain other changes to the terms of the 2022 Credit Agreement, including modifications of the financial covenants thereunder. Holders of the Notes will also receive additional Notes upon the in-kind payment of interest on any outstanding Notes. The Notes will be convertible into shares of Common Stock of the Company at a fixed conversion price of $0.25 (subject to adjustment, the “Conversion Price”).

In addition, as part of the Transaction, the Company has agreed to certain corporate governance changes, including that (i) John Maldonado, an affiliate of the Advent Stockholders, will resign from the Board upon closing of the Transaction, (ii) HPS Investment Partners, LLC, will have the right to appoint one board observer to the Board under certain circumstances, (iii) the Preferred Equityholders’ pre-existing rights as holders of the Company’s Series A Senior Preferred Stock to designate and elect one director to the Board, will be revised to provide that (A) the Preferred Equityholders have the right to appoint three additional directors to the Company’s Board (resulting in the right of the Preferred Equityholders to appoint a total of four directors to the Board) until such time after the Closing Date that the Lead Purchaser (in each case, as defined in certain of the transaction agreements entered into in connection with the original issuance of the Series A Preferred Stock) ceases to hold at least 50.1% of the Series A Preferred Stock held by it as of the Closing Date, one of whom must be unaffiliated with (and independent of) the Preferred Equityholders and who must meet the definition of “independent” under the listing standards of the NYSE, and by the SEC, (B) all such designee directors of the Preferred Equityholders will be subject to consideration by the Board of Directors (acting in good faith and consistent with their review of other Board candidates), (iv) the provision in the certificate of designation of our Series A Senior Preferred Stock that eliminated the Preferred Equityholders’ director designation rights upon the Company’s achievement of certain amounts of EBITDA will be deleted (and the equivalent provision in that certain Investors’ Rights Agreement, dated as of February 24, 2022, by and among the Company and the Preferred Equityholders listed therein, will also be deleted), (v) as further described in Proposal 2, the Declassification Proposal, contingent upon approval of this Transaction Proposal and if the Declassification Proposal is also approved by our stockholders, the Board will be declassified to effect, among other things, that all

go-forward appointments or elections of directors to the Board, including the directors nominated for election at this Annual Meeting, will be for terms of one year or until the next annual meeting of stockholders, as applicable (for the avoidance of doubt, without affecting the length of the terms of other directors of the Board that are in effect on the date on which the Transaction is consummated), and (vi) the Advent Stockholders will no longer have the right to appoint five directors to the Board and the Stockholders Agreement, dated as of February 21, 2021, by and among the Fortress Value Acquisition Corp. II and certain entities affiliated with Advent (the “Stockholders Agreement”) will be terminated.

This discussion of the Transaction is qualified in its entirety by reference to the Signing Date Definitive Documents, which are filed as exhibits to our current report on Form 8-K filed with the SEC on April [•], 2023 (the “Definitive Document 8-K”). You should read the Definitive Document 8-K, including the exhibits thereto, carefully and in its entirety.

We believe that the Transaction will have numerous benefits for the Company, including to enhance the Company’s liquidity, increase the Company’s financial flexibility and allow the Company to comply with the covenants under its Credit Agreement.

Our Common Stock is listed on the New York Stock Exchange (“NYSE”), and, as such, we are subject to the NYSE Continued Listing Standards, including NYSE Listed Company Manual Section 312.03. NYSE Section 312.03 provides that, subject to certain exceptions, stockholder approval is required prior to the issuance of common stock, or securities convertible into or exercisable for common stock, in certain circumstances, including the following:

If this Proposal is approved and the Transaction closes, we intend to issue up to an aggregate of $125.0 million of Notes, which, based on the Conversion Price, would be convertible into 500 million shares of Common Stock (or a range of 10 million to 25 million shares of Common Stock on a post-split basis if Proposal 5 for the Reverse Stock Split is approved by the stockholders at this Annual Meeting), or, as converted, approximately 71% of the Company’s outstanding Common Stock as of March 31, 2023. As a result, the issuance of the Notes and the shares of Common Stock issuable upon conversion of the Notes, will result in a change of control of the Company. The Company is also obligated under NYSE rules to obtain stockholder approval prior to the issuance of the Notes held by the Preferred Equityholders because (i) certain of the Preferred Equityholders, as substantial security holders of the Company, are Related Parties under the rules and regulations of the NYSE and (ii) the number of shares of Common Stock into which the Notes are proposed to be converted would exceed 1% of the number of shares of Common Stock outstanding before such issuance.

We are seeking stockholder approval of this Transaction Proposal in order to comply with the NYSE Continued Listing Standards discussed above and to satisfy conditions under certain of the Definitive Documents. The closing of the Transaction is conditioned upon approval of this Transaction Proposal by a majority of the Company’s stockholders. Approval of the Reverse Stock Split pursuant to Proposal 5 will enable the Company to have enough authorized shares of Common Stock under its Charter to implement the Transaction. Pursuant to the A&R TSA, Advent has agreed to support the Transaction and vote in favor of this Transaction Proposal and the Reverse Stock Split Proposal, subject to certain conditions as outlined in the A&R TSA.

The following is a summary of the material features of the Notes.

Draws. Draws on the Delayed Draw Amounts will be available beginning immediately upon the closing of the Transaction (the “Closing Date”) and ending on the date that is 18 months after the Closing Date, the Company may request either (i) two draws in an amount of $12.5 million each, or (ii) one draw in an amount of $25.0 million, subject in each case to, (a) projected liquidity at any time during the 6-month period following the date of the relevant draw being below either (i) $20 million or (ii) the prevailing minimum liquidity covenant threshold, as determined by reference to the Credit Agreement and (b) the consent of our Board. The Note Purchase Agreement also provides, subject to certain conditions and consent rights outlined in the Note Purchase Agreement, the issuance by the Company of up to an additional $150.0 million in Notes. Proceeds of the Notes will be used for general corporate purposes, subject to certain exceptions.

Interest. The Notes will bear interest at a rate of 8.00% per annum, payable quarterly in-kind in the form of additional Notes by capitalizing the amount of such interest on the outstanding principal balance of the Notes in arrears on each interest payment date.

Maturity. The Notes will mature on August 24, 2028, unless earlier repurchased or converted.

Conversion. The Notes may be converted, in whole or in part (if the portion to be converted is $1,000 principal amount or an integral multiple thereof), at the option of the holder, into shares of Common Stock based on the Conversion Price. The initial Conversion Price represents a discount of approximately 3% based on the NYSE Minimum Price.

Adjustments to Conversion Price. The Conversion Price is subject to adjustment as a result of the following events:

Guarantees; Collateral; Ranking. The Notes will be guaranteed by Wilco Holdco, Inc., Wilco Intermediate Holdings, Inc., ATI Holdings Acquisition, Inc., and the subsidiaries of ATI Holdings Acquisition, Inc. that guaranty the obligations under the Credit Agreement. The Notes will be secured by the same collateral that secures the obligations under the Credit Agreement.

Pursuant to the terms of an intercreditor and subordination agreement, the Notes (and the guarantees thereof) will rank junior in right of payment to the obligations under the Credit Agreement, and the liens on the collateral securing the Notes will rank junior to the liens on such collateral securing the obligations under the Credit Agreement.

Other Covenants. The Note Purchase Agreement includes affirmative and negative covenants (other than financial covenants) that are substantially consistent with the Credit Agreement, as well as customary events of default.

Voting. The Company will issue to each holder of Notes shares of Series B Preferred Stock (the “Series B Preferred Stock”) in an amount equal to the quotient (rounded down to the nearest whole number) obtained by dividing (A) the amount paid by such holder to the Company for the Notes by (B) $1,000. The holders of Series B Preferred Stock shall have full voting rights and powers equal to the voting rights and powers of the holders of Common Stock, and shall be entitled to notice of any stockholders' meeting in accordance with the bylaws of the Company, shall be entitled to vote, together with holders of Common Stock, with respect to any question upon which holders of Common Stock have the right to vote. Fractional votes shall not, however, be permitted, and any fractional voting rights available on an as-converted basis (after aggregating all shares into which shares of Series B Preferred Stock held by each holder could be converted) shall be rounded down to the nearest whole share of Series B Preferred Stock.

The Series B Preferred Stock shall not have any dividend, distribution or redemption rights or, right to receive any distribution of any of the Company’s assets.

In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company, the holders of Series B Preferred Stock shall be entitled to be paid out of the assets of the Company available for distribution to its stockholders, after satisfying any senior payment obligations and before any payment in respect of any Common Stock, an amount per share of Series B Preferred Stock equal to $0.0001.

The Series B Preferred Stock shall be governed in all respects by Delaware law.

The terms of the Notes and the Series B Preferred Stock are qualified in their entirety by reference to the (a) Note Purchase Agreement, filed as Exhibit [•] to the Definitive Document 8-K, (b) the Certificate of Designation of Series B Preferred Stock, which is included as Exhibit D to the Note Purchase Agreement, and (c) our Charter.

Provisions of the Delaware General Corporation Law (“DGCL”) and our Charter and Bylaws could make it more difficult to acquire the Company by means of a tender offer, a proxy contest or otherwise, or to remove incumbent officers and directors. These provisions, summarized below, are intended to discourage coercive takeover practices and inadequate takeover bids and to encourage persons seeking to acquire control of the Company to first negotiate with the board of directors. We believe that the benefits of these provisions outweigh the disadvantages of discouraging certain takeover or acquisition proposals because, among other things, negotiation of these proposals could result in an improvement of their terms and enhance the ability of the Board to maximize stockholder value. However, these provisions may delay, deter or prevent a merger or acquisition of us that a stockholder might consider is in its best interest, including those attempts that might result in a premium over the prevailing market price of our Common Stock.

We have opted out of Section 203 of the DGCL; however the Charter contains a provision that is substantially similar to Section 203, but excludes Advent and its affiliates and successors and investment funds affiliated with Advent (the “Excluded Parties”) from the definition of “interested stockholder,” and make certain related changes. Upon consummation of the Business Combination, the Excluded Parties became “interested stockholders” within the meaning of Section 203 of the DGCL, but are not subject to the restrictions on business combinations set forth in Section 203, as the FAII Board approved the Business Combination in which the Excluded Parties became interested stockholders prior to such time they became interested stockholders.

Generally, under our Charter the Company shall not engage in any business combination, at any point in time at which the Common Stock is registered under Section 12(b) or 12(g) of the Securities Exchange Act of 1934, as amended, with any interested stockholder for a period of three years following the time that such stockholder became an interested stockholder, unless:

In addition, our Charter provides for certain other provisions that may have an anti-takeover effect:

Though we have agreed, subject to stockholder approval, to commence the declassification of our Board beginning at this Annual Meeting, as further described above and in Proposal 2, under the terms of our Charter, our Board is currently divided into three classes, with one class of directors being elected in each year and each serving a three-year term. Each class of directors is voted on at the annual meeting of the stockholders of the Company every third year. Directors are elected by a plurality of the votes cast at a meeting of the stockholders by holders of Common Stock. So long as the Board is classified, it would take at least two elections of directors for any individual or group to gain control of the Board. Accordingly, while the classified board is in effect, these provisions could discourage a third party from initiating a proxy contest, making a tender offer or otherwise attempting to gain control of the Company.

Our Bylaws provide that stockholders seeking to bring business before the annual meeting of the stockholders, or to nominate candidates for election as directors at the annual meeting of the stockholders, must provide timely notice of their intent in writing. To be timely, a stockholder’s notice will need to be received by the Company’s secretary at our principal executive offices not later than the close of business on the 90th nor earlier than the close of business on the 120th day prior to the anniversary date of the immediately preceding annual meeting of the stockholders. Pursuant to Rule 14a-8 of the Exchange Act, proposals seeking inclusion in our annual proxy statement must comply with the notice periods contained therein. Our Bylaws also specify certain requirements as to the form and content of a stockholders’ meeting. These provisions may preclude our stockholders from bringing matters before our annual meeting of the stockholders or from making nominations for directors at our annual meeting of the stockholders.

FAII and certain holders of Common Stock affiliated with Advent are currently parties to the Stockholders Agreement, pursuant to which, among other things, Advent is entitled to designate for nomination to the Board (A) five directors if Advent holds equal to or greater than 50% of the outstanding shares of Common Stock, (B) four

directors if Advent holds less than 50% but equal to or greater than 38% of the outstanding shares of Common Stock, (C) three directors if Advent holds less than 38% but equal to or greater than 26% of the outstanding shares of Common Stock, (D) two directors if Advent holds less than 26% but equal to or greater than 13% of the outstanding shares of Common Stock and (E) one director if Advent holds less than 13% but equal to or greater than 5% of the outstanding shares of Common Stock.

As part of the Transaction and contingent on approval of this Transaction Proposal, the Company and the Parties have agreed that the Stockholders Agreement and Advent’s designation rights will be terminated. In addition, if this Proposal is approved, certain lenders under the 2022 Credit Agreement will have the right to appoint one board observer to the Board under certain circumstances, and the Preferred Equityholders will have the right to appoint a total of four directors to the Board.

The Bylaws provide that, unless ATI consents to the selection of an alternative forum, any (A) derivative action or proceeding brought on behalf of ATI, (B) action asserting a claim of breach of a fiduciary duty owed by any director, officer, stockholder or employee to ATI or its stockholders, (C) action asserting a claim against ATI or its directors, officers or employees arising pursuant to any provision of the DGCL or our Charter or the Bylaws or (D) action asserting a claim against ATI or its directors, officers or employees governed by the internal affairs doctrine shall, to the fullest extent permitted by law, be exclusively brought in the Court of Chancery of the State of Delaware. Additionally, the Bylaws also provide that, to the fullest extent permitted by law, unless ATI consents to the selection of an alternative forum, the federal district courts of the United States of America will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act. Any person or entity purchasing or otherwise acquiring any interest in shares of capital stock of ATI shall be deemed to have notice of and consented to the forum provisions in the Bylaws. This exclusive forum provision will not apply to claims under the Exchange Act but will apply to other state and federal law claims including actions arising under the Securities Act. Section 22 of the Securities Act, however, creates concurrent jurisdiction for federal and state courts over all suits brought to enforce any duty or liability created by the Securities Act or the rules and regulations thereunder. Accordingly, there is uncertainty as to whether a court would enforce such a forum selection provision as written in connection with claims arising under the Securities Act, and investors cannot waive compliance with the federal securities laws and the rules and regulations thereunder.

Pursuant to the A&R TSA and the Signing Date Definitive Documents, the closing of the Transaction is contingent upon the approval this Proposal by the stockholders at the Annual Meeting. Advent, who beneficially owns approximately 56% of our Common Stock as of March 31, 2023, has, pursuant to the A&R TSA, agreed to support the Transaction and vote in favor of this Transaction Proposal at the Annual Meeting, subject to certain conditions as outlined in the A&R TSA.

If the Company does not complete the Transaction or otherwise access additional financing, the Company will need to consider other alternatives, including pursuing separate amendments to or waivers of the minimum liquidity covenant, the requirement to deliver audited financial statements without certain going concern qualifications, and other requirements under the Credit Agreement, as well as raising funds from other sources, obtaining alternate financing, disposal of assets, or pursuing other strategic alternatives to improve its liquidity position and business results.

If the Transaction Proposal is approved, the Company will issue to our Preferred Equityholders up to an aggregate $125.0 million of Notes (plus additional Notes upon the in-kind payment of interest on any outstanding Notes) that are convertible into shares of Common Stock of the Company at the Conversion Price, and holders thereof will have the right to vote on corporate matters on an as-converted basis as described above, which will significantly dilute the voting power of the Company’s current stockholders, giving them a smaller percentage interest in the aggregate book value of the Company. This dilutive effect may be material to our current stockholders. In addition, the Preferred Equityholders and HPS will receive Board designation rights as described above.

Certain of our affiliates have interests in this Proposal that may be different from, or in addition to, the interests of our stockholders generally. Our Preferred Equityholders who currently own 100% of our Series A Senior Preferred

Stock, have the right to designate and elect one director to the Board and, subject to approval by the stockholders of this Proposal, upon closing of the Transaction will own approximately 71% of our Common Stock on an as-converted basis, and will receive the Board designation rights as described above.

As of March 31, 2023, Advent beneficially owned approximately 56% of our Common Stock. Pursuant to the A&R TSA, Advent has agreed to support the Transaction and vote in favor of this Transaction Proposal and the Reverse Stock Split Proposal, subject to certain conditions as outlined in the A&R TSA.

Our Board of Directors was aware of these interests and considered them, among other matters, in approving the Transaction and in approving this Proposal and declaring it advisable.

The affirmative vote of a majority of the votes cast at the Annual Meeting is required to approve this Transaction Proposal.

Our Charter provides for a classified Board divided into three classes of directors, with directors in each class being elected for staggered three-year terms. Under this current structure, only one class of directors, constituting approximately one-third of the Board, is considered for election at each annual meeting of stockholders. As part of the Transaction, our Board has approved certain corporate governance changes, including, subject to stockholder approval of the Transaction and of this Proposal, the declassification of our Board over time. Therefore, contingent upon approval of the Transaction Proposal as set forth in Proposal 1, we are asking our stockholders to approve an amendment and restatement of our Charter to phase out the classified Board so that all directors are elected for one-year terms (and the Board is fully declassified) by our 2025 annual meeting (the “Third Amended and Restated Certificate”), subject to the special rights of the holders of one or more outstanding series of our preferred stock to elect directors. The Board recommends that stockholders vote “FOR” the Third Amended and Restated Certificate, a copy of which is attached hereto as Appendix A.

Contingent on approval of the Transaction Proposal, if approved by our stockholders, we will amend and restate our Charter to make changes to Article V as set forth in Appendix A to this Proxy Statement to provide that our classified Board structure will be phased out beginning at this 2023 Annual Meeting, such that from and after the 2025 annual meeting of stockholders, all directors will be up for election at each annual meeting and will serve for a term of one year and until such directors’ successors are duly elected and qualified or until such directors’ earlier death, resignation or removal.

If the Third Amended and Restated Certificate is approved, the phase out of the classified Board will commence at the 2023 Annual Meeting, at which the directors originally elected or appointed to Class II are up for election, and each director up for election at the 2023 Annual Meeting will be elected for a one-year term. Then, at the 2024 annual meeting of stockholders, the directors elected at the 2023 meeting, along with the directors originally appointed to Class III, together with any directors appointed to fill vacancies or newly created directorships, will be up for election, and each such director will be elected for a one-year term. Finally, at the 2025 annual meeting of stockholders, all directors will be up for election, and each director elected at the 2025 annual meeting of stockholders (and at all annual meetings thereafter) will be elected for a one-year term and until their successors are duly elected and qualified or until their earlier death, resignation or removal. The phasing in of annual elections of directors over this period is designed so that the term of any incumbent director will not be shortened, and to ensure a smooth transition over time to a system of annual elections of all our directors.

The Third Amended and Restated Certificate provides that, subject to the special rights of the holders of one or more outstanding series of our preferred stock to elect directors, directors elected or appointed to fill any vacancy on the Board, or to fill newly created director positions resulting from an increase in the number of directors, would serve until the next annual meeting following such director’s election or appointment. The Third Amended and Restated Certificate does not change the provisions relating to the establishment of the total number of directors constituting the Board.

In addition, under Delaware law, unless the certificate of incorporation provides otherwise, where the board of directors is classified, directors may be removed only for cause. At present, because our Board is classified, our Charter provides that our directors may be removed only for cause, and only by the affirmative vote of holders of a majority of the voting power of all then outstanding shares of capital stock of the Company entitled to vote generally in the election of directors, voting together as a single class. If the proposed Third Amended and Restated Certificate is approved, directors will be subject to removal, with or without cause, by the affirmative vote of holders of a majority of the voting power of all then outstanding shares of capital stock of the Corporation entitled to vote generally in the election of directors, voting together as a single class.

This description of the amendments to our Charter set forth in the Third Amended and Restated Certificate is only a summary of the proposed amendments to our Charter and is qualified by reference to the full text of the Third Amended and Restated Certificate, which has been included as Appendix A to this Proxy Statement and is incorporated by reference herein.

If the Transaction Proposal is not approved, or if the Third Amended and Restated Certificate is not approved, we will continue to have a classified board and our Class II directors, Ms. Burns, Mr. Maldonado, Mr. Parisi and Ms. Vitti will stand for election to a three-year term expiring at the 2026 annual meeting of stockholders.

The affirmative vote of the holders of at least 66.7% of the outstanding shares of our common stock entitled to vote is required to approve this proposal.

If our stockholders approve the proposed Third Amended and Restated Certificate, we intend to file the Third Amended and Restated Certificate with the Secretary of State of the State of Delaware promptly after such approval is received and prior to taking a vote on the election of directors at the 2023 Annual Meeting. The Third Amended and Restated Certificate will become effective upon the effectiveness of its filing. In that case, each of the directors originally appointed to Class II who are nominated for election at the Annual Meeting would stand for election under Proposal 4-A for a one-year term expiring at the 2024 annual meeting.

Our Audit Committee has selected Deloitte & Touche LLP as our independent registered public accounting firm to perform the audit of our consolidated financial statements for the fiscal year ending December 31, 2023, and recommends that the stockholders vote for ratification of such selection. Deloitte & Touche LLP was engaged as our independent registered public accounting firm effective April 4, 2023, which was after the Company filed its Annual Report on Form 10-K for the year ended December 31, 2022 with the SEC (the Form “10-K”). The Company dismissed the prior auditor, PricewaterhouseCoopers LLP (“PwC”) after the filing of the Form 10-K. The ratification of the selection of Deloitte & Touche LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2023 requires the affirmative vote of a majority of the votes cast by the stockholders present in person or represented by proxy at the Annual Meeting and entitled to vote thereon. The Board considers the selection of our independent registered public accounting firm to be an important matter of stockholder concern and considers the proposal for stockholders to ratify such selection to be an important opportunity for stockholders to provide direct feedback to the Board on an important issue of corporate governance. In the event that Deloitte & Touche LLP is not ratified by our stockholders, the Audit Committee will review its future selection of Deloitte & Touche LLP as our independent registered public accounting firm, but may ultimately determine to retain Deloitte & Touche LLP. Even if the appointment is ratified, the Audit Committee, in its sole discretion, may direct the appointment of a different independent registered public accounting firm at any time during the year if the Audit Committee determines that such a change would be in the best interests of the Company and its stockholders.

PwC audited our financial statements for the fiscal years ended December 31, 2021 and 2022 and served as our independent registered public accounting firm through the fiscal year ended on December 31, 2022. We expect representatives of both Deloitte & Touche LLP and PwC, to be present at the Annual Meeting. They will have an opportunity to make a statement if they so desire and are expected to be available to respond to appropriate questions by stockholders.

On April 4, 2023, upon the completion of a comprehensive selection process, the Audit Committee dismissed PwC as the Company’s independent registered public accounting firm, to be effective as of the date the Form 10-K was filed. The reports of PwC on the consolidated financial statements of the Company as of, and for, the fiscal years ended December 31, 2022 and 2021 did not contain an adverse opinion or a disclaimer of opinion and were not qualified or modified as to uncertainty, audit scope, or accounting principles.

During the Company’s fiscal years ended December 31, 2022 and 2021, there were: (i) no disagreements within the meaning of Item 304(a)(1)(iv) of Regulation S-K between the Company and PwC on any matter of accounting principles or practices, financial statement disclosure, or auditing scope or procedure, any of which, if not resolved to PwC’s satisfaction, would have caused PwC to make reference thereto in their reports, and (ii) no “reportable events” within the meaning of Item 304(a)(1)(v) of Regulation S-K.

On April 4, 2023, the audit committee approved the engagement of Deloitte & Touche LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2023, effective immediately after the Company filed its Form 10-K. During the Company’s fiscal years ended December 31, 2022 and 2021, neither the Company nor anyone acting on its behalf consulted with Deloitte regarding: (i) the application of accounting principles to a specific transaction, either completed or proposed, or the type of audit opinion that might be rendered on the Company’s financial statements, and neither a written report nor oral advice was provided to the Company that Deloitte concluded was an important factor considered by the Company in reaching a decision as to any accounting, auditing, or financial reporting issue, (ii) any matter that was the subject of a disagreement within the meaning of Item 304(a)(1)(iv) of Regulation S-K, or (iii) any “reportable event” within the meaning of Item 304(a)(1)(v) of Regulation S-K.

We regularly review the services and fees from our independent registered public accounting firm. These services and fees are also reviewed with our Audit Committee annually.

During the fiscal years ended December 31, 2022 and 2021, aggregate fees for services and related expenses provided by PwC were as follows.

The following table shows the fees for professional services rendered to us by PwC, our prior independent registered public accounting firm, for services in respect of the years ended December 31, 2022 and 2021:

All of the services relating to the fees described in the table above were approved by our Audit Committee.

The purpose of our Audit Committee is to assist our Board of Directors with oversight of (i) the conduct and integrity of the Company’s and its subsidiaries’ (collectively the “Company Group”) external financial reporting; (ii) the performance of the Company Group’s internal audit function and systems of internal control over financial reporting and disclosure controls and procedures; (iii) the qualifications, engagement, compensation, independence and performance of the Company Group’s independent auditors, their conduct of the annual audit of the Company Group’s financial statements, and their engagement to provide any other services; (iv) the Company Group’s legal and regulatory compliance (other than health care compliance matters); and (v) the application of the Company Group’s policies and procedures as established by management and the Board. Our Audit Committee’s principal responsibility is one of oversight. Our management is responsible for determining that our financial statements are complete, accurate, and in accordance with generally accepted accounting principles and establishing satisfactory internal control over financial reporting. The independent auditor is responsible for auditing our financial statements and the effectiveness of our internal control over financial reporting. Our internal and outside counsel are responsible for assuring compliance with laws and regulations and our corporate governance policies.

In the performance of its oversight function, our Audit Committee has:

Based on these reviews and discussions, we recommended to our Board of Directors the inclusion of the audited financial statements in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022, as filed with the SEC on March 16, 2023.

Set forth below are alternative proposals for the election of directors.

As further described in the Transaction Proposal and Declassification Proposal, if both such Proposals are approved, we will file our Third Amended and Restated Certificate of Incorporation with the Secretary of State of the State of Delaware promptly following such approvals and during the Annual Meeting before the vote is taken to elect directors to allow us to proceed with Proposal 4-A for the annual election of our Class II directors. If the Transaction Proposal and Declassification Proposal are approved, Proposal 4-A will apply and the current Class II directors will each be nominated for election for a one year term. At the 2024 annual meeting of stockholders, any directors elected at the 2023 meeting along with our Class III directors, together with any directors appointed to fill vacancies or newly created directorships, will stand for election for a one year term. At our 2025 annual meeting of stockholders, all directors will be nominated for election for a one-year term.

If the Transaction Proposal or Declassification Proposal are not approved by our stockholders at the Annual Meeting, Proposal 4-B will apply and we will not commence declassification. In that case, our Class II directors will each be nominated for election for a three year term.

If the Company’s stockholders approve the Transaction Proposal and Declassification Proposal as described above, the stockholders will be asked to consider four nominees for election to the Board, each of whom would serve for a one-year term until the 2024 annual meeting of stockholders of the Company, and until such director’s successor is duly elected and qualified or until such director’s earlier death, resignation, or removal.

Our Board of Directors currently consists of nine directors and is currently divided into three classes. Each class serves for three years, with the terms of office of the respective classes expiring in successive years. Directors in Class II will stand for election at the Annual Meeting. The terms of office of directors in Class I and Class III do not expire until the annual meetings of stockholders held in 2025 and 2024, respectively. At the recommendation of our Nominating and Corporate Governance Committee, our Board of Directors proposes that, upon the approval of the Transaction Proposal and Declassification Proposal and confirmation of the filing of the Third Amended and Restated Certificate of Incorporation with the Secretary of State of the State of Delaware, each of the four Class II nominees named below, each of whom is currently serving as a director in Class II, be nominated for a one-year term expiring at the 2024 annual meeting of stockholders and until such director’s successor is duly elected and qualified or until such director’s earlier death, resignation, or removal. Each director will be elected by a plurality of the votes cast by the stockholders present in person or represented by proxy at the meeting and entitled to vote thereon, which means that the four individuals nominated for election to our Board of Directors at the Annual Meeting receiving the highest number of “FOR” votes will be elected.

If the Transaction Proposal is approved and the Transaction is consummated, Mr. Maldonado will resign from the Board.

Shares represented by proxies will be voted “FOR” the election of each of the four nominees named below, unless the proxy is marked to withhold authority to so vote. If any nominee for any reason is unable to serve or for good cause will not serve, the proxies may be voted for such substitute nominee as the proxy holder might determine. Each nominee has consented to being named in this Proxy Statement and to serve if elected. Proxies may not be voted for more than three directors. Stockholders may not cumulate votes for the election of directors.

IF THE TRANSACTION PROPOSAL AND DECLASSIFICATION PROPOSAL ARE APPROVED BY STOCKHOLDERS, OUR BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR ALL NOMINEES” IN THE ELECTION OF THE DIRECTORS.

If the Company’s stockholders do not approve the Transaction Proposal and Declassification Proposal as described above, the stockholders will be asked to consider three Class II directors for election to the Board, each of whom would serve as a Class II director for a three-year term until the 2026 annual meeting of stockholders of the Company.

The Company’s stockholders will be asked to vote on this Proposal No. 4-B solely in the event that at the Annual Meeting, the Company’s stockholders do not approve the Transaction Proposal or Declassification Proposal. If the Company’s stockholders approve the Transaction Proposal and Declassification Proposal, then the Company will amend its Charter to commence the elimination of its classified Board by filing the Third Amended and Restated Certificate of Incorporation with the Secretary of State of the State of Delaware during the Annual Meeting as described above, and the stockholders will proceed to vote on Proposal No. 4-A and not this Proposal No. 4-B. If, however, the Company’s stockholders do not approve of the Transaction Proposal or Declassification Proposal, a vote will be taken on this Proposal No. 4-B.

Our Board of Directors currently consists of nine directors and is divided into three classes. Each class serves for three years, with the terms of office of the respective classes expiring in successive years. Directors in Class II will stand for election at the 2023 Annual Meeting. The terms of office of directors in Class I and Class III do not expire until the annual meetings of stockholders held in 2025 and 2024, respectively. At the recommendation of our Nominating and Corporate Governance Committee, our Board of Directors proposes that each of the three Class II nominees named below, each of whom is currently serving as a director in Class II, be elected as a Class II director for a three year term expiring at the 2026 annual meeting of stockholders and until such director’s successor is duly elected and qualified or until such director’s earlier death, resignation, or removal. Each director will be elected by a plurality of the votes cast by the stockholders present in person or represented by proxy at the meeting and entitled to vote thereon, which means that the three individuals nominated for election to our Board of Directors at the Annual Meeting receiving the highest number of “FOR” votes will be elected.

Shares represented by proxies will be voted “FOR” the election of each of the four nominees named below, unless the proxy is marked to withhold authority to so vote. If any nominee for any reason is unable to serve or for good cause will not serve, the proxies may be voted for such substitute nominee as the proxy holder might determine. Each nominee has consented to being named in this Proxy Statement and to serve if elected. Proxies may not be voted for more than three directors. Stockholders may not cumulate votes for the election of directors.

IF THE TRANSACTION PROPOSAL OR DECLASSIFICATION PROPOSAL ARE NOT APPROVED BY STOCKHOLDERS, OUR BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR ALL NOMINEES” IN THE ELECTION OF THE DIRECTORS.

The nominees and their ages, occupations, and length of service on our Board of Directors as of the date of this Proxy Statement, are provided below.

Ms. Burns, age 62, joined our Board in 2021. Prior to serving on the Board, Ms. Burns served as the Chief Strategy Officer for Cerner Corporation, a healthcare IT company, from 2013 to 2019. Ms. Burns serves on the board of directors of Availity, a healthcare claims clearinghouse, as the chair of the performance and compensation committee and a member of the finance committee. Ms. Burns also serves on the board of directors of Innara Health, a neonatal medical device company, and she is chair of the board of directors and the compensation committee of SNOMED International, an international non-profit organization focused on clinical terminology used in electronic health records. Ms. Burns received her B.S. from the State University of New York College at Plattsburgh and her M.P.A. from the University of San Francisco.

Mr. Parisi, age 58, joined our Board in 2021. Since May, 2018 Mr. Parisi has served on the board of directors of Cboe Global Markets, Inc., a global exchange operator, as the chair of the audit committee, a member of the compensation committee and a member of the Alternative Trading System oversight committee. Previously, Mr. Parisi served on the board of directors of Cotiviti Inc., a clinical and financial analytics company, as the Chair of the audit committee and a member of the board strategy committee from 2015 until 2018. Mr. Parisi also served on the board of directors for Cboe Futures Inc., a futures exchange, where he was a member of the regulatory oversight committee from 2016 until 2018 and served on the board of directors of Pursuant Health, Inc., a provider of self-service health and wellness testing kiosks, as the chair of the audit committee from 2014 until 2021. Mr. Parisi served as Chief Financial Officer of CME Group Inc., a publicly traded company, from 2004 through 2014. Mr. Parisi received his B.S. from the University of Illinois at Urbana-Champaign and his M.B.A. from the University of Chicago Booth School of Business.

Ms. Vitti came to ATI Physical Therapy as Chief Executive Officer in 2022 with nearly 30 years of experience in healthcare. Before joining the Company, Ms. Vitti served as Senior Vice President at CVS Health and President of MinuteClinic, where she led all aspects of care delivery, business operations and strategic development. Prior to Vitti’s tenure at CVS Health and MinuteClinic, she served in executive leadership at Brigham and Women’s Hospital, including nine years as Senior Vice President of Clinical Services for Ambulatory and Women’s Health. Vitti received her Bachelor of Science degree from Clark University and a Master of Public Administration from New York University.

Mr. Maldonado, age 47, has served on our Board since 2016. Mr. Maldonado is a Managing Partner at Advent. Prior to joining Advent in 2006, he worked at Bain Capital, Parthenon Capital and the Parthenon Group. He also currently serves on the Board of Directors of Iodine Software and AccentCare, Inc., a provider in post-acute healthcare services (“AccentCare”), RxBenefits, a pharmacy adviser to employee benefits consultants, Healthcare Private Equity Association, an association that supports the healthcare private equity community and . Mr. Maldonado received his B.A. in mathematics, summa cum laude, from Dartmouth College and his M.B.A., with high distinction, as a Baker Scholar from Harvard Business School.

The directors who are serving for terms that end after the Annual Meeting and their ages, occupations, and length of service on our Board of Directors as of the date of this Proxy Statement are provided below.

Mr. Dourney, age 66, joined our Board in February 2022. Mr. Dourney joined the Board of National Spine and Pain Centers in February, 2023. From April 2019 to June 2021, Mr. Dourney served as President and Chief Executive Officer of Professional PT, LLC, a provider of outpatient physical and hand therapy and rehabilitation services. Previously, from May 2016 to March 2019, he was the President and Chief Operations Officer of OptimisCorp, a

medical technology provider, and, prior to that was the COO of Physiotherapy Associates, an outpatient physical and occupational rehabilitation service and health and wellness program provider, from May 2014 to March 2016. Mr. Dourney has served on the board of directors of OptimisCorp since May 2016. Mr. Dourney received a bachelor’s degree from State University of New York Upstate Medical University and is a physical therapist.

Mr. Larsen, age 65, has served on our Board since 2018 and has served as the Chair of the Board since 2021. He also served as Executive Chairman and a member of the leadership team fulfilling the role of Principal Executive Officer until April 28, 2022. Mr. Larsen’s role at the Company has primarily been to work alongside executives and board members, participating in and nurturing broad networks of alliances with others. Mr. Larsen is an executive at Bridgeway Partners LLC (“Bridgeway”) and Cloverfields, LLC (“Cloverfields”). Prior to forming Bridgeway in 2020, Mr. Larsen served in various roles at UnitedHealth Group from 2005 until 2018. Mr. Larsen was also an executive at Gondola Eye, LLC from 2019 until 2020.

Ms. Sparks joined the Company Board in December 2021 and is currently a member of the Audit Committee. From October 2018 to August 2020, Ms. Sparks served as Chief Financial Officer (“CFO”) and Executive Vice President of Envision Healthcare, a leading provider of physician-led services and post-acute care services in addition to ambulatory surgery services. Previously, from March 2018 to September 2018, she was the interim CFO at Brookdale Senior Living, and, prior to that, was the CFO at Surgery Partners and its predecessor company, Symbion, Inc., from November 2014 to January 2018. Ms. Sparks currently serves on the board of directors of Harrow Health, Inc., a publicly traded ophthalmic-focused healthcare company, where she is chair of the audit committee and a member of the nominating and governance and compensation committees. Ms. Sparks also serves on the board of directors and as chair of the audit committee of several other private companies. Ms. Sparks received a B.S. in Business Administration and Accounting Summa Cum Laude from Trevecca Nazarene University.

Mr. McKnight served as Chief Executive Officer and a director of Fortress Value Acquisition Corp. II, which completed its merger with ATI Physical Therapy (“ATI”) in June 2021. Mr. McKnight is a Managing Partner of the Credit Funds business at Fortress. Mr. McKnight is based in Dallas and heads the liquid credit investment strategies at Fortress, serves on the investment committee for the Credit Funds business at Fortress and is a member of the Management Committee of Fortress. Mr. McKnight previously served on the board of directors of Mosaic Acquisition Corp. from 2017 to 2020. Mr. McKnight has also served on the board of directors and as the Chief Executive Officer of Fortress Value Acquisition Corp. since its inception in January 2020 and continues to serve on the board of directors of MP Materials where he is a member of the Compensation Committee. Additionally, Mr. McKnight has served as a director and Chief Executive Officer of FVAC III since its inception in August 2020, and as Chairman of the FVAC IV board. Prior to joining Fortress in February 2005, he was the trader for Fir Tree Partners (“Fir Tree”) where he was responsible for analyzing and trading high yield and convertible bonds, bank debt, derivatives and equities for the value-based hedge fund. Prior to Fir Tree, Mr. McKnight worked on Goldman, Sachs & Co.’s (“Goldman”) distressed bank debt trading desk. Mr. McKnight is a member of ATI’s Health Care Compliance Committee. Mr. McKnight received a B.A. in Economics from the University of Virginia.

Mr. Petrone, age 40, has served on our Board since 2016 and currently serves as the Chair of the Compensation Committee. Mr. Petrone is a Managing Director at Advent, focused on investments in the healthcare sector. Mr. Petrone has worked on more than 12 Advent investments. Mr. Petrone currently serves on the board of AccentCare and Iodine Software. Prior to joining Advent in 2010, Mr. Petrone was an associate at Thomas H. Lee Partners from 2006 to 2008. Mr. Petrone currently serves on the Board of Directors of AccentCare. He holds a B.A. in Economics from the John Hopkins University and an M.B.A. from Harvard Business School.

In 2022, each non-employee director, except for Carmine Petrone, John Maldonado and Andrew McKnight, received annual compensation in the form of a $75,000 annual cash retainer and restricted stock unit and stock option awards valued at $100,000, as well as additional retainers for committee chairs and, to a lesser extent, members. John Larsen, our Executive Chairman, received an additional $50,000 annual cash retainer and $25,000 restricted stock award for serving as Chairman of the Board.

The director restricted stock unit grant for 2022 vests on the first anniversary of the grant date and entitles the director to receive shares of our Common Stock upon vesting, and the director stock option grant for 2022 vests one-third on each of the first three anniversaries of the date of the grant, all as further described below. The terms of the Award Agreements with the directors are otherwise the same as the executives.

Annual cash retainers are paid on a quarterly basis at the end of each quarter and include committee fees detailed below.

The following persons were our executive officers as of December 31, 2022:

Our Board of Directors chooses executive officers, who then serve at the discretion of our Board of Directors. There is no family relationship between any of the directors or executive officers and any of our other directors or executive officers.

Ms. Vitti came to ATI Physical Therapy as Chief Executive Officer in 2022 with nearly 30 years of experience in healthcare. Before joining the Company, Ms. Vitti served as Senior Vice President at CVS Health and President of MinuteClinic, where she led all aspects of care delivery, business operations and strategic development. Prior to Vitti’s tenure at CVS Health and MinuteClinic, she served in executive leadership at Brigham and Women’s Hospital, including nine years as Senior Vice President of Clinical Services for Ambulatory and Women’s Health. Vitti received her Bachelor of Science degree from Clark University and a Master of Public Administration from New York University.

Mr. Jordan has more than 20 years of financial experience, serving as a leader for almost half that time. As Chief Financial Officer of the Company since 2019, Mr. Jordan is responsible for financial operations, including accounting, tax and financial reporting. He sets the organization’s strategic direction and analyzes financial strengths as well as ways to drive change and process improvements. His expertise is expansive, including SEC reporting, SOX compliance, forecasting and technical accounting matters. Prior to being named as CFO, Mr. Jordan served as the Company's Senior Vice President and Chief Accounting Officer, beginning in 2018. Before ATI, Mr. Jordan worked at Sears Holding Corporation (“Sears”), starting as the Assistant Controller and advancing to Vice President and Corporate Controller. He began his career in 2003 and held various positions at Deloitte & Touche LLP and Sun Coke Energy before joining Sears. Mr. Jordan received his B.S. in Accounting from Purdue University and is a Certified Public Accountant.

Mr. Cox was named Chief Operating Officer in 2022. In this role, he oversees the Company's ATI Worksite Solutions and Sports Medicine businesses — together known as Health Services — as well as field operations, revenue cycle management, payer contracting and reimbursement, central scheduling and telehealth support, and transformation & enterprise project management. Prior to ATI, Mr. Cox spent nearly 15 years in senior leadership positions at CVS Health. He holds an M.B.A. from The Wharton School at the University of Pennsylvania with a dual concentration in Finance and General Management, and an undergraduate degree from Duke University.

Mr. Kantz joined ATI in 2016 as Assistant General Counsel Mergers & Acquisitions. Prior to that, Mr. Kantz was a partner and Vice Chair of the Business Group at Saul Ewing Arnstein & Lehr LLP, and was previously partner and Director of Operations at College Sports Chicago. He holds a bachelor’s degree from Illinois Wesleyan University and a juris doctor degree from DePaul University.

Mr. Oakes was named Chief Information Officer of the Company in 2020, and prior to assuming the role, Mr. Oakes served the Company as Vice President of Business Technology beginning in 2018. Prior to joining the Company, Mr. Oakes served as a management consultant at KPMG LLP from 2013 until 2018, where he helped companies build modern IT operating models and prepare for digital disruption. Mr. Oakes also served in various IT leadership roles at Walgreen Company, d/b/a Walgreens (“Walgreens”) and as a management consultant with Accenture plc. Mr. Oakes holds a degree from Loyola University Chicago.

Mr. Gregerson joined ATI as Chief Growth Officer in January 2023. In this role, he leads growth initiatives across business development, mergers and acquisitions, sales, marketing, real estate, and other potential future growth opportunities. Prior to joining ATI, Mr. Gregerson served in executive-level positions with several large hospital and health systems. He holds a bachelor’s degree from the University of California, Santa Barbara and a juris doctor degree from Washington and Lee University School of Law.

Ms. Tansey joined ATI Physical Therapy as Chief People Officer in August 2022 with more than 20 years' experience in Human Resources and Operations. Before coming to ATI, she served as Chief People Officer at elder-care provider InnovAge. Prior to that, Ms. Tansey held various HR leadership positions at CVS Health for more than a decade, rising to Vice President of Human Resources. She holds a Master of Science, Human Resources Management from the University of Maryland Global Campus and a Bachelor of Arts in Political Science and Government from Ohio Wesleyan University.

The following table sets forth, as of March 31 2023, certain information with respect to the beneficial ownership of our Common Stock for each of our named executive officers, each of our directors, all of our directors and executive officers as a group and each person we know to be the beneficial owner of more than 5% of our Common Stock.

In accordance with the rules of the SEC, beneficial ownership includes voting or investment power with respect to securities and includes the shares of common stock issuable pursuant to options and warrants that are exercisable or settled within 60 days of the date of this table. Shares of common stock issuable pursuant to options and warrants are deemed outstanding for computing the percentage of the class beneficially owned by the person holding such securities but are not deemed outstanding for computing the percentage of the class beneficially owned by any other person. Except as otherwise indicated, all share ownership is as of March 31, 2023 and the percentage of beneficial ownership is based on 207,384,260 shares of Common Stock legally outstanding.

The business address of each beneficial owner is c/o ATI Physical Therapy, Inc., 790 Remington Blvd., Bolingbrook, IL 60440, unless otherwise indicated below.

At the Annual Meeting, the stockholders will be asked to approve an amendment to the Company’s Charter to effect a reverse stock split (the “Reverse Stock Split”). Such approval will require the affirmative vote of majority of the votes cast by the stockholders present in person or represented by proxy at the meeting and entitled to vote thereon. On April __, 2023, our Board of Directors approved the amendment to our Certificate of Incorporation (the “Reverse Stock Split Amendment”), a copy of which is attached hereto as Appendix B.

If the Transaction Proposal and the Declassification Proposal are approved and the Company files a Third Amended and Restated Certificate of Incorporation to implement the declassification, the Reverse Stock Split will be an amendment to the Third Amended and Restated Certificate of Incorporation. If Proposal 2 is not approved, the Reverse Stock Split Amendment will be an amendment to the Second Amended and Restated Certificate of Incorporation.

If approved by our stockholders, the Reverse Stock Split Amendment would permit, but would not require, the Board to effect a Reverse Stock Split of our Common Stock issued and outstanding or held in treasury, as well as the number of shares issuable upon the exercise or vesting of all then-outstanding stock options, warrants and restricted stock units convertible into Common Stock by a ratio of not less than 1-for-20 and not more than 1-for-50, with the exact ratio to be set at a whole number within this range as determined by the Board (or a duly authorized committee thereof) in its sole discretion. The Reverse Stock Split, if effected, would affect all of our holders of Common Stock uniformly.

If this Proposal is approved by our stockholders, we intend to file with the Secretary of State of the State of Delaware the Reverse Stock Split Amendment and implement the Reverse Stock Split as soon as practicable after the Annual Meeting, in order to enable the Company to have enough authorized shares of Common Stock available under its Charter to implement the Transaction (see the Transaction Proposal). The Board also may determine in its discretion not to effect the Reverse Stock Split and not to file the Reverse Stock Split Amendment. No further action on the part of stockholders will be required to either implement or abandon the Reverse Stock Split.

The following description of the proposed amendment is a summary and is subject to the full text of the proposed Reverse Stock Split Amendment, a copy of which is attached hereto as Appendix B.

The Board’s primary objective in proposing the Reverse Stock Split is to raise the per share trading price of the Company’s Common Stock. As noted above, the Reverse Stock Split would also enable the Company to have enough authorized shares of Common Stock available under its Charter to implement the Transaction (see the Transaction Proposal).

NYSE Compliance. On November 18, 2022, the Company received a notice from the New York Stock Exchange (“NYSE”) that the Company was not in compliance with one of the NYSE’s continued listing standards, as the average closing price of the Company’s Common Stock was less than $1.00 per share over a consecutive 30- trading day period. Pursuant to the NYSE’s continued listing standards, the Company has six months following receipt of the notice to regain compliance with the minimum share price requirements, with the possibility of extension at the discretion of the NYSE. In order to regain compliance, on the last trading day in any calendar month during the cure period, the Company’s Common Stock must have: (i) a closing price of at least $1.00 per share; and (ii) an average closing price of at least $1.00 per share over the 30 trading day period ending on the last trading day of such month. The Company’s failure to regain compliance during this period could result in delisting.

Continued Listing on NYSE. The Board believes that the continued listing of our Common Stock on the NYSE is beneficial for our stockholders and that the anticipated increased market price of the Company’s Common Stock that will result from the Reverse Stock Split may enhance the Company’s ability to regain compliance with the NYSE’s minimum share price requirements for continued listing. If the NYSE were to delist the Company’s Common Stock for any reason, it could negatively impact our reputation and, as a consequence, our business, and would likely decrease the liquidity and market price of our Common Stock; the number of investors willing to hold or acquire our

Common Stock; our ability to access equity markets, issue additional securities and obtain additional financing in the future; and our ability to provide equity incentives to our employees.

Investor Considerations. The Board also believes that the anticipated increased market price of the Company’s Common Stock that may result from the Reverse Stock Split may encourage investor interest and improve the marketability of the Common Stock to a broader range of investors. Because of the trading volatility often associated with low-priced stocks, many brokerage firms and institutional investors have internal policies and practices that either prohibit them from investing in low-priced stocks or tend to discourage individual brokers from recommending low-priced stocks to their customers. The closing sale price of our Common Stock on March 31, 2023, was $0.2542 per share.

To decrease the risk of market manipulation of our common stock. The Board believes that the potential increase in stock price may reduce the risk of market manipulation of our common stock, which we believe is enhanced when our stock trades below $1.00 per share. By reducing market manipulation risk, we may also thereby potentially decrease the volatility of our stock price.

Reverse Stock Split Ratio. The purpose of seeking stockholder approval of exchange ratios within the ratio range (rather than a fixed exchange ratio) is to provide the Company with the flexibility to achieve the desired results of the Reverse Stock Split. If the stockholders approve this proposal, then the Board or an authorized committee thereof, in its sole discretion, would affect the Reverse Stock Split only upon the determination by the Board or an authorized committee thereof that such action would be in the best interests of the Company and our stockholders at that time. If the Board, or an authorized committee thereof, were to effect the Reverse Stock Split, then the Board or such committee would set the effective date and select the final ratio. No further action on the part of stockholders would be required to either implement or abandon the Reverse Stock Split. If the stockholders approve the proposal, and the Board or an authorized committee thereof determines to effect the Reverse Stock Split, we would communicate to the public, prior to the effective date, additional details regarding the Reverse Stock Split, including the final ratio selected by the Board or an authorized committee thereof.

The Reverse Stock Split Amendment is not being proposed in response to any effort of which we are aware to accumulate shares of our outstanding Common Stock or obtain control of the Company, nor is it a plan by management to recommend such actions to our Board or our stockholders. We anticipate that the Reverse Stock Split will, however, contribute to the Company being able to execute the Transaction if approved by stockholders, which, as described in the Transaction Proposal, will result in the Preferred Equityholders’ accumulation of securities convertible into approximately 71% of the Company’s outstanding Common Stock as of March 31, 2023.

The primary effects of the reverse stock split as of the effective date would be:

The Board believes that the Reverse Stock Split will increase the price of the Company’s Common Stock in order to, among other things:

Risk related to Reverse Stock Split. The Board cannot predict, however, the effect of the Reverse Stock Split upon the market price for the Company’s Common Stock, and the history of similar reverse stock splits for companies in like circumstances is varied.

Fractional Shares. The Reverse Stock Split will affect all stockholders of the Company uniformly and will not affect any stockholder’s percentage ownership interests or proportionate voting power, except to the extent that the Reverse Stock Split results in any stockholders owning a fractional share. If a stockholder would otherwise receive a fractional share post-split the share amount will be rounded to the next whole share. The principal effect of the Reverse Stock Split will be to reduce the 207,384,260 outstanding shares as of March 31, 2023 by the ratio range of 1-for-20 to 1-for-50 shares, depending on the final ratio chosen by the Board or an authorized committee thereof.

Outstanding Equity Rights. In addition, all outstanding options, stock appreciation rights, warrants, restricted stock awards and restricted stock units (collectively, the “Outstanding Equity Rights”), entitling the holders thereof to acquire, through purchase, exchange or otherwise, shares of Common Stock will enable such holders to acquire upon exercise of their respective Outstanding Equity Rights that number of shares of Common Stock, as applicable, as adjusted based on the final ratio, which such holders would have been able to purchase upon exercise or conversion, as and to the extent applicable, of their respective Outstanding Equity Rights immediately preceding the Reverse Stock Split, at an exercise price or conversion rate, as and to the extent applicable, equal to the exercise price or conversion rate, as applicable, specified before the Reverse Stock Split, as adjusted by the final ratio, resulting in the same aggregate price being required to be paid upon exercise or conversion thereof immediately preceding the Reverse Stock Split.

The Reverse Stock Split will reduce the number of outstanding shares of our Common Stock without a proportionate reduction in the number of shares of authorized but unissued Common Stock in our Certificate of Incorporation, which will give the Company a significantly larger number of authorized shares, as a percentage of total outstanding shares, available to be issued in the future without further stockholder action, except as may be required by applicable laws or the rules of any stock exchange on which our Common Stock is listed. The issuance of additional shares of our Common Stock may have a dilutive effect on the ownership of existing stockholders. The larger number of authorized but unissued shares will contribute to the Company being able to execute the Transaction, which, as described in the Transaction Proposal, will result in the Preferred Equityholders’ accumulation of securities convertible into approximately 71% of the Company’s outstanding Common Stock as of March 31, 2023.

The Reverse Stock Split may result in some stockholders owning “odd lots” of less than 100 shares of Common Stock. Odd lot shares may be more difficult to sell, and brokerage commissions and other costs of transactions in odd lots may be higher than the costs of transactions in “round lots” of even multiples of 100 shares.

Par Value. The Reverse Stock Split will not affect the par value of the Company’s Common Stock. As a result, on the effective date, the present value of the stated capital on the Company’s balance sheet attributable to the

Common Stock will be reduced based on the final ratio, and the additional paid-in capital account will be increased with the amount by which the stated capital is reduced. The per share net loss and net book value of the Common Stock will be retroactively increased for each period because there will be fewer shares of Common Stock outstanding.

The table below illustrates the effect, as of one for twenty to one for fifty of a Reverse Stock Split at certain ratios on (i) the shares of Common Stock issued and outstanding; (ii) the shares of Common Stock reserved for future issuance under the Company’s 2021 Equity Incentive Plan, as amended, as well as any other securities underlying the Common Stock; and (iii) the resulting number of shares of Common Stock available for issuance:

As noted above, the Reverse Stock Split would result in an increased proportion of unissued authorized shares to issued shares, which could have possible anti-takeover effects and could be used by us to oppose a hostile takeover attempt or to delay or prevent changes in our control or management (for example, by permitting issuances that would dilute the stock ownership of a person seeking to effect a change in the composition of the board of directors or contemplating a tender offer or other transaction for the combination of us with another company). These authorized but unissued shares could (within the limits imposed by applicable law) be issued in one or more transactions that could make a change of control of the Company more difficult, and therefore more unlikely, or used to resist or frustrate a third-party transaction that is favored by a majority of the independent stockholders. For example, without further stockholder approval, our Board could (within the limits imposed by applicable law) strategically sell shares of Common Stock in a private transaction to purchasers who would oppose a takeover or favor our then current Board, or the shares could be available for potential issuance pursuant to a stockholder rights plan.

The additional authorized shares could be used to discourage persons from attempting to gain control of the Company by diluting the voting power of shares then outstanding or increasing the voting power of persons that would support the Board in a potential takeover situation, including by preventing or delaying a proposed business combination that is opposed by the Board although perceived to be desirable by some stockholders. The issuance of additional shares to certain persons allied with our management could have the effect of making it more difficult to remove our current management by diluting the stock ownership or voting rights of persons seeking to cause such removal.

Despite these possible anti-takeover effects, this Reverse Stock Split amendment has been prompted by business and financial considerations and not by the threat of any hostile takeover attempt or any effort of which we are aware to accumulate our stock or to obtain control of our company by means of a merger, tender offer, solicitation in opposition to management or otherwise (nor is our Board currently aware of any such attempts directed at us).

Nevertheless, stockholders should be aware that approval of this Proposal could facilitate future efforts by us to deter or prevent changes in our control, including transactions in which the stockholders might otherwise receive a premium for their shares over then current market prices.

If the Reverse Stock Split Amendment is approved by the Company’s stockholders, and the Board or an authorized committee thereof determines it is in the best interests of the Company and our stockholders to effect the

Reverse Stock Split, then the Reverse Stock Split would become effective at such time as the Reverse Stock Split Amendment, the form of which is attached as Appendix B to this Proxy Statement, is filed with the Secretary of State of the State of Delaware.

If, at any time prior to the filing of the Reverse Stock Split Amendment with the Delaware Secretary of State, notwithstanding stockholder approval, and without further action by the stockholders, the Board, in its sole discretion, determines that it is in the Company’s best interests and the best interests of the Company’s stockholders to delay the filing of the Reverse Stock Split Amendment or abandon the Reverse Stock Split, the Reverse Stock Split may be delayed or abandoned.

The Company reserves the right to abandon a reverse stock split without further action by our stockholders at any time before the effectiveness of the filing with the Secretary of the State of Delaware of the Reverse Stock Split Amendment to our Certificate of Incorporation, even if the authority to effect the Reverse Stock Split has been approved by our stockholders at the Annual Meeting. By voting in favor of the Reverse Stock Split Amendment, you are expressly also authorizing the board of directors to delay, not to proceed with, and abandon, the Reverse Stock Split if it should so decide, in its sole discretion, that such action is in the best interests of the Company and its stockholders.

As soon as practicable after the effective date, stockholders will be notified that the Reverse Stock Split has been effected. Continental Stock Transfer & Trust Company, the Company’s transfer agent, will act as exchange agent for purposes of implementing the exchange. Stockholders whose shares are held by a brokerage firm, bank or other similar organization do not need to take any action with respect to the exchange.

These shares will automatically reflect the new quantity of shares based on the Reverse Stock Split. However, these brokerage firms, banks or other similar organizations may have different procedures for processing the Reverse Stock Split, and stockholders whose shares are held by a brokerage firm, bank or other similar organization are encouraged to contact their brokerage firm, bank or other similar organization.

Certain registered holders of our Common Stock hold some or all of their respective shares electronically in book-entry form with the transfer agent. These stockholders do not have stock certificates evidencing their ownership of our Common Stock. Stockholders who hold shares electronically in book-entry form with the transfer agent will not need to take action to receive whole shares of post-Reverse Stock Split Common Stock because the exchange will be automatic.

New CUSIP number. If a Reverse Stock Split is effected, then after the effective time, our Common Stock will have a new Committee on Uniform Securities Identification Procedures (“CUSIP”) number, which is a number used to identify our equity securities, and stock certificates with the older CUSIP number will need to be exchanged for stock certificates with the new CUSIP number by following the procedures described below. After the Reverse Stock Split, we will continue to be subject to the periodic reporting and other requirements of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). We currently expect that our Common Stock will continue to be listed on the NYSE under the symbol “ATIP” subject to any future change of listing of our securities, although it will be considered a new listing with a new CUSIP number. The Reverse Stock Split is not intended to be, and we do not believe that it will have the effect of, a “going private transaction” covered by Rule 13e-3 under the Exchange Act.

The Company will not issue fractional shares for post-Reverse Stock Split shares in connection with the Reverse Stock Split, each partial share will be rounded to the nearest whole share.

If the stockholders approve the Reverse Stock Split Amendment, then the Board or an authorized committee thereof will be authorized to proceed with the Reverse Stock Split. In determining whether to proceed with the Reverse Stock Split and setting the final ratio, if any, the Board or an authorized committee thereof will consider a number of factors, including NYSE listing requirements, market conditions, existing and expected trading prices of the Company’s Common Stock, and actual or forecasted results of operations.

Under the General Corporation Law of the State of Delaware, stockholders will not be entitled to dissenter’s rights or appraisal rights with respect to the Reverse Stock Split Amendment, and the Company does not intend to independently provide stockholders with any such right.

The following discussion is a summary of certain material U.S. federal income tax consequences of the Reverse Stock Split to stockholders that hold their shares of Common Stock as capital assets for U.S. federal income tax purposes, but does not purport to be a complete analysis of all potential tax effects that may be relevant to stockholders. The effects of other U.S. federal tax laws, such as estate and gift tax laws, and any applicable state, local, or foreign tax laws are not discussed. This summary is based upon the provisions of the U.S. Internal Revenue Code (the “Code”) Treasury Regulations promulgated thereunder, administrative rulings and judicial decisions, all as in effect as of the date hereof, and all of which are subject to change and differing interpretations, possibly with retroactive effect. Changes in these authorities or their interpretation may result in the U.S. federal income tax consequences of the Reverse Stock Split differing substantially from the consequences summarized below.

This summary is for general information purposes only and does not address all aspects of U.S. federal income taxation that may be relevant to stockholders in light of their particular circumstances, including the impact of the alternative minimum tax, the Medicare surtax on net investment income or the special tax accounting rules under Section 451(b) of the Code, or to stockholders that may be subject to special tax rules, including, without limitation: (i) banks, insurance companies, or other financial institutions; (ii) tax-exempt organizations; (iii) dealers in securities or commodities; (iv) regulated investment companies or real estate investment trusts; (v) partnerships (including entities or arrangements treated as partnerships for U.S. federal income tax purposes and their partners or members); (vi) traders in securities that elect to use the mark-to-market method of accounting; ( vii) persons whose “functional currency” is not the U.S. dollar; (viii) persons holding our Common Stock in a hedging transaction, “straddle,” “conversion transaction” or other risk reduction transaction; (ix) persons who acquired our Common Stock in connection with employment or the performance of services; (x) retirement plans; (xi) persons who are not U.S. Holders (as defined below); or (xii) certain former citizens or long-term residents of the United States. In addition, this summary of certain material U.S. federal income tax consequences does not address the tax consequences arising under the laws of any foreign, state or local jurisdiction or any U.S. federal tax consequences other than U.S. federal income taxation (such as U.S. federal estate and gift tax consequences). If a partnership (including any entity or arrangement treated as a partnership for U.S. federal income tax purposes) holds shares of our Common Stock, the tax treatment of a partner in the partnership generally will depend upon the status of the partner, the activities of the partnership, and certain determinations made at the partner level. Partnerships holding our Common Stock and the partners in such partnerships should consult their tax advisors regarding the tax consequences to them of the Reverse Stock Split.

We have not sought, and will not seek, an opinion of counsel or a ruling from the Internal Revenue Service (the “IRS”) regarding the U.S. federal income tax consequences of the Reverse Stock Split and there can be no assurance that the IRS will not challenge the statements and conclusions set forth below or that a court would not sustain any such challenge.

INVESTORS SHOULD CONSULT THEIR TAX ADVISORS WITH RESPECT TO THE APPLICATION OF THE U.S. FEDERAL INCOME TAX LAWS TO THEIR PARTICULAR SITUATIONS AS WELL AS ANY TAX CONSEQUENCES OF THE REVERSE STOCK SPLIT ARISING UNDER THE U.S. FEDERAL ESTATE OR GIFT TAX LAWS OR UNDER THE LAWS OF ANY STATE, LOCAL OR NON-U.S. TAXING JURISDICTION OR UNDER ANY APPLICABLE INCOME TAX TREATY.

This summary addresses only stockholders that are U.S. Holders. For purposes of this discussion, a “U.S. Holder” is any beneficial owner of our Common Stock that, for U.S. federal income tax purposes, is or is treated as any of the following:

The Reverse Stock Split should constitute a “recapitalization” for U.S. federal income tax purposes. Assuming the Reverse Stock Split qualifies as a “recapitalization” for U.S. federal income tax purposes, then, except as described below with respect to cash received in lieu of fractional shares, a stockholder should not recognize gain or loss as a result of the Reverse Stock Split. A stockholder’s aggregate tax basis in the shares of the Common Stock received pursuant to the Reverse Stock Split should equal the stockholder’s aggregate tax basis in the shares of the Common Stock surrendered (excluding any portion of such basis that is allocated to any fractional share of our Common Stock), and such stockholder’s holding period in the shares of the Common Stock received should include the holding period of the shares of the Common Stock surrendered. Treasury Regulations promulgated under the Code provide detailed rules for allocating the tax basis and holding period of shares of Common Stock surrendered pursuant to the Reverse Stock Split to shares of Common Stock received pursuant to the Reverse Stock Split. Stockholders holding shares of Common Stock that were acquired on different dates and at different prices should consult their tax advisors regarding the allocation of the tax basis and holding period of such shares.

A stockholder who receives cash in lieu of a fractional share of Common Stock should be treated as first receiving such fractional share and then receiving cash in redemption of such fractional share. A stockholder who receives cash in lieu of a fractional share in the Reverse Stock Split should recognize capital gain or loss equal to the difference between the amount of the cash received in lieu of the fractional share and the portion of the stockholder’s adjusted tax basis allocable to the fractional share. Stockholders should consult their tax advisors regarding the tax effects to them of receiving cash in lieu of fractional shares based on their particular circumstances.

A stockholder may be subject to information reporting with respect to any cash received in exchange for a fractional share interest in a new share in the Reverse Stock Split. Stockholders who are subject to information reporting and who do not provide a correct taxpayer identification number and other required information (such as by submitting a properly completed IRS Form W-9) may also be subject to backup withholding at the applicable rate. Any amount withheld under such rules is not an additional tax and may be refunded or credited against the stockholder’s U.S. federal income tax liability, provided that the required information is properly furnished in a timely manner to the IRS.

The Board of Directors seeks stockholder approval of the Reverse Stock Split Amendment to comply with applicable NYSE listing requirements and with the amendment provisions of the Certificate of Incorporation.

The Reverse Stock Split Amendment will not become effective unless and until stockholder approval is obtained. If stockholders do not approve this Proposal 5, the Certificate of Incorporation will instead remain in effect in accordance with its pre-existing terms and without giving effect to the Reverse Stock Split Amendment.

The Board of Directors believes that approval of the Reverse Stock Split Amendment is in the best interest of the Company and its stockholders.

OUR BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE “FOR” THE APPROVAL OF THE REVERSE STOCK SPLIT AMENDMENT.

The following is a summary of transactions (or series of transactions) and any currently proposed transactions, to which we have been or will be a participant and in which the amount involved exceeded or will exceed $120,000, and in which any of our directors, director nominees, executive officers or holders of more than 5% of any class of our equity interests at the time of such transaction, or any members of their immediate family, had or will have a direct or indirect material interest.

As described in the Transaction Proposal, if the Transaction Proposal is approved and the Transaction closes, we intend to issue to our Preferred Equityholders, including funds affiliated with Knighthead Capital Management, LLC (the “Investors”) up to an aggregate of $125.0 million of Notes, which, based on a fixed exchange price of $0.25 per share, would be exchangeable into approximately 500 million shares of Common Stock (or a range of 10 million to 25 million shares of Common Stock on a post-split basis if Proposal 5 for the Reverse Stock Split is approved by the stockholders at this Annual Meeting), or, as-converted, approximately 71% of the Company’s outstanding Common Stock as of March 31, 2023.

As of March 31, 2023, Advent beneficially owned approximately 56% of our Common Stock. Pursuant to the A&R TSA, Advent has agreed to support the Transaction and vote in favor of this Transaction Proposal and the Reverse Stock Split Proposal, subject to certain conditions as outlined in the A&R TSA.

On June 15, 2020, FAII issued founder shares (“Founders Shares”) in exchange for an aggregate capital contribution of $25,000. Fortress Acquisition Sponsor II LLC (“Sponsor”) had agreed to forfeit an aggregate of up to 1,125,000 Founder Shares to the extent that the over-allotment option was not exercised in full by the underwriters. On August 14, 2020, the underwriters exercised their over-allotment option in full. As a result, the 1,125,000 Founder Shares were no longer subject to forfeiture. In August 2020, Sponsor transferred a total of 100,000 Founder Shares to four independent directors of FAII for the same per-share price initially paid for by Sponsor. Subsequent to those transfers, Sponsor held 8,525,000 Founder Shares. The Founder Shares automatically converted into Common Stock upon the consummation of the Business Combination (“Vesting Shares”).

Pursuant to the Parent Sponsor Letter Agreement, the Insiders (as defines therein) further agreed that, all of the Vesting Shares shall be unvested and shall be subject to certain vesting and forfeiture provisions, as follows: (i) 33.33% of the Vesting Shares beneficially owned by the Insiders shall vest at such time as a $12.00 Common Share Price is achieved on or before the date that is ten years after the consummation of the Business Combination, (ii) 33.33% of the Vesting Shares beneficially owned by the Insiders shall vest at such time as a $14.00 Common Share Price is achieved on or before the date that is ten years after the consummation of the Business Combination and (iii) 33.34% of the Vesting Shares beneficially owned by the Insiders shall vest at such time as a $16.00 Common Share Price is achieved on or before the date that is ten years after the consummation of the Business Combination.

Substantially concurrently with the closing of FAII’s initial public offering (“IPO”), the Sponsor purchased an aggregate 5,933,333 Private Placement Warrants for a price of $1.50 per warrant. Each Private Placement Warrant was exercisable to purchase one share of FAII Class A common stock at $11.50 per share.

Each Private Warrant entitles the holder to purchase one share of our Common Stock at $11.50 per share. At the closing of the Business Combination, the Sponsor transferred and surrendered for no consideration 2,966,667 of its Private Placement Warrants. 2,966,666 Private Placement Warrants are outstanding at this time.

Prior to FAII’s IPO, the Sponsor loaned FAII an aggregate of $97,250 to cover expenses related to FAII’s IPO pursuant to a promissory note. The promissory note was non-interest bearing, unsecured and due on the earlier of April 30, 2021 and the closing of the FAII’s IPO. FAII repaid the promissory note in full on August 14, 2020.

On August 14, 2020, FAII entered into an agreement with an affiliate of Sponsor to pay a monthly fee of $20,000 for office space and related support services. Upon completion of the Business Combination, we ceased paying these monthly fees

In connection with the PIPE Investment and consummation of the Business Combination, the Sponsor purchased 7,500,000 shares of FAII Class A common stock at $10.00 per share for an aggregate purchase price of $75 million.

After the consummation of the Business Combination, Wilco Acquisition, LP (the sole holder of the Company Common Stock as of the date of the Merger Agreement) or its designees had the contingent right to receive Earnout Shares upon the terms and subject to the conditions set forth in the Merger Agreement and the agreements contemplated thereunder in the amounts set forth below if the price targets set forth below are achieved any time between the closing and the date that is ten years after the consummation of the Business Combination:

In the event that there is an agreement with respect to the sale or other change of control of ATI entered into after the closing and prior to the date that is ten years after the consummation of the Business Combination, that will result in the holders of Common Stock receiving a per share price in excess of the applicable VWAP set forth above, then the applicable Earnout Shares that have not such sale or change of control, ATI and the surviving company will take proper provision to ensure that any Earnout Shares that have not previously been issued will remain eligible to be paid through the date that is ten years after the consummation of the Business Combination.

If, after the closing and on or before the date that is ten years after the consummation of the Business Combination, the outstanding shares of Common Stock are changed into a different number or class of shares by reason of any merger, stock split, division or subdivision of shares, stock dividend, reverse stock split, consolidation of shares, reorganization, reclassification, recapitalization or other similar transaction, then the number of Earnout Shares to be issued pursuant to the Merger Agreement will be adjusted to the extent appropriate to provide the same economic effect as contemplated by the Merger Agreement prior to such action.

We have reimbursed Wilco GP, Inc., which is affiliated with Advent, for expenses totaling approximately $174,547 for the period covering January 1, 2021 to December 31, 2021. The reimbursed expenses were incurred in the normal course of business and related to third-party expenses for board member search fees, the performance of proactive internal audit related to our cybersecurity capabilities, travel expenses and external legal and consulting fees.

On the Refinancing Date, the Company entered into a Series A Preferred Stock Purchase Agreement with the purchasers signatory thereto, including (the “Investors”), pursuant to which the Investors purchased from the Company, in the aggregate, 165,000 shares of Series A Preferred Stock with an initial stated value of $1,000 per share, or $165.0 million of stated value in the aggregate, which includes warrants to purchase up to 11.5 million shares of Common Stock, for an aggregate purchase price of $163,350,000. The Series A Preferred Stock has priority over the Common Stock with respect to distribution rights, liquidation rights and dividend rights. The holders of the Series A Preferred Stock are entitled to cumulative dividends on the preferred shares at an initial dividend rate of 12.0%, which are payable in-kind, increasing 1.0% per annum on the first day following the fifth anniversary of the issuance and each one-year anniversary thereafter. However, from and after the third anniversary of the issuance of such preferred equity, we have the option to pay such dividends in cash at an interest rate of 1.0% lower than the paid-in-kind rate. The Series A Preferred Stock is perpetual and is mandatorily redeemable in certain circumstances such as a change of control, liquidation, winding up or dissolution, bankruptcy or other insolvency event, restructuring or capitalization transaction, or event of noncompliance.

The Series A Preferred Stock includes approximately 11.5 million detachable warrants. Each warrant entitles the holder to purchase one share of Common Stock. The warrants are exercisable within 5 years from issuance. The strike price is $3.00 for 5.2 million of the issued warrants, and the strike price is $0.01 for 6.3 million of the issued warrants.

If the Transaction is approved, the Series A Preferred Stock will be amended as described in Proposal 1.

On the Refinancing Date, the Company also entered into an Investors’ Rights Agreement with the Investors (the “Investors’ Rights Agreement”). The Investors’ Rights Agreement sets forth the Investors’ right to designate one director to the Company’s Board of Directors (subject to certain conditions as summarized above) and to receive certain quarterly and annual financial and other information of the Company. The Investors’ Rights Agreement also sets forth restrictions on transfer of shares of Series A Preferred Stock by the Investors and rights of first refusal in favor of any holder that, individually or together with its affiliates, holds, in the aggregate, at least 25% of the then-outstanding Series A Preferred Stock. The Company also agreed in the Investors’ Rights Agreement to pay expenses incurred by Investors in connection with (i) any amendment, modification or waiver of a provision of any Transaction Document and (ii) the enforcement by the Investors of any of their rights in connection with the Transaction Documents, in each case subject to the terms and conditions set forth in the Investors’ Rights Agreement.

If the Transaction is approved, the Investors’ Rights Agreement will be amended as described in Proposal 1.

We maintain a Related Person Transaction Policy (the “Policy”) that sets forth the following policies and procedures for the review and approval or ratification of related person transactions by our Audit Committee. In accordance with the policy, our Audit Committee has overall responsibility for implementation of and compliance with the policy.

Generally and subject to certain exceptions, a “Related Person Transaction” is a transaction, arrangement or relationship in which ATI or any of its subsidiaries was, is or will be a participant, involving an amount exceeding $120,000 and in which any related person (as defined in the Policy) had, has or will have a direct or indirect material interest.

The Policy requires that notice of a proposed transaction or arrangement that could be a Related Person Transaction be provided in advance (or otherwise at the earliest possible opportunity) to the Chief Legal Officer or designee in the Legal Department, the Chair of the Board, the Chair of the Audit Committee or the Accounting Department. If it is determined that such transaction could be a Related Person Transaction, the proposed transaction will be submitted to our Audit Committee for consideration at its next meeting or sooner if determined to be necessary by the Accounting and Legal Departments, in consultation with the Chief Executive Officer or Chief Financial Officer, to the Chair of the Audit Committee. Under the Policy, the Audit Committee may, in its discretion based upon a determination that such transactions are in the best interests of the Company and such other determinations as the Audit Committee deems appropriate, (i) approve in advance such transactions, as applicable, (ii) request that the transaction be modified as a condition to the Board’s approval or ratification, or (iii) reject the transaction.

We have also adopted policies and procedures designed to minimize potential conflicts of interest arising from any dealings we may have with our affiliates and have appropriate procedures for the disclosure of any real or potential conflicts of interest that may exist from time to time.

This Compensation Discussion and Analysis (“CD&A”) describes the material components of our executive compensation program during fiscal year 2022 and provides an overview of our compensation philosophy and objectives for our named executive officers (“NEOs”).

Our executive compensation program is designed to align total compensation with Company performance, while enabling us to attract, retain, and motivate individuals who can achieve sustained long-term growth and strong financial performance for our stockholders. Our pay-for-performance driven compensation philosophy and practices are directly tied to increased stockholder value. As a result, NEO compensation is heavily weighted towards providing equity awards and incenting for long-term stock price appreciation.

Our NEOs for 2022 consisted of:

Our Compensation Committee is responsible for oversight of our executive compensation program, which is regularly reviewed and discussed with management to ensure alignment with our short-term and long-term goals given the dynamic nature of our business and the market in which we compete for talent.

Our Compensation Committee is primarily responsible for establishing executive compensation. It does so with the goals of motivating NEOs to achieve our business goals and objectives and enhance long-term stockholder value, while rewarding them for their contribution in achieving these goals and objectives. Our Compensation Committee considers the interests of stockholders and overall Company performance in establishing compensation for our NEOs. Our Compensation Committee and management reference national surveys and publicly available executive officer data for similar companies and general industry as an input for compensation decisions.

Management assists our Compensation Committee in establishing NEO compensation by providing information on Company and individual performance, market data, and business needs, strategy, and objectives. Our Compensation Committee also considers our Chief Executive Officer’s recommendations regarding adjustments to NEO compensation components (other than with respect to their own compensation, for which they recuse themselves from all discussions and recommendations).

Our Compensation Committee evaluates our executive compensation programs in comparison to those of a select peer group, which in 2021 consisted of 14 similarly-sized public health care facilities companies. Our Compensation Committee uses the peer group to compare total direct compensation and the mix of compensation elements for each named executive officer against positions at peer group companies with similar responsibilities. Our Compensation Committee also uses the peer group to review executive pay programs and practices at those companies. For 2021 the peer group consisted of the following companies, which our Compensation Committee determined would be adequate to rely on and would continue to be used for 2022:

In setting compensation, the Committee considers the peer group companies with which we directly compete for executive talent and stockholder investment. Our Compensation Committee also relies on its general knowledge of executive compensation levels and practices. Most of the Company’s executive search and leadership advisory competitors, from which executive talent is often recruited, are privately held, and therefore not included in the above list of our public peer group companies as information on their compensation practices is difficult to obtain.

We do not set a specific, relative percentile positioning for total direct compensation, or the elements of total direct compensation, as a target for named executive officer pay levels. Rather, we review the total direct compensation range for each position and the mix of elements to ensure that compensation is adequate to attract and retain key named executive officers. Our named executive officer compensation program is also designed to ensure that a significant proportion of the named executive officer’s compensation is delivered in equity and thus aligned with the interests of our stockholders.

The Company considers base salary, cash bonus, long-term incentive awards, health and wellness benefits, career development and perquisites as an executive’s Total Rewards. The Total Rewards model emphasizes an individual’s complete remuneration from the company. It allows the Company to compare the full suite of incentive and retentive tools with those of our peers. Use and consideration of an executive’s Total Reward helps the Company ensure we are retaining the best talent in the industry and motivating the highest levels of performance.

ATI is a purpose-driven company focused on extraordinary patient outcomes. We value fair pay for our high-performing talent in a fast-paced, exciting culture. We aim to build and evolve our business with individuals who are committed to improving the lives of others. We seek leaders who are passionate about this mission and want to join our culture of excellence. Our Total Rewards approach to compensation is designed to attract, incentivize, and retain high-quality talent as well as promote our unique corporate culture.

Our executive compensation program for our NEOs is comprised of the following key components, aligning to our Total Rewards Model, each of which is further described below:

Base salary is a standard element of compensation required to attract and retain talent and provide executives with a base level of cash income. Our Compensation Committee reviews and determines base salary adjustments as part of its annual NEO compensation review, as well as when an NEO is promoted into a new position. In connection with our SPAC transaction, and the change to a public company, our Board increased the base salaries of two of our NEOs, which led to the following base salaries for the NEOs as of the beginning and the end of 2022, as follows:

The Company maintains the Annual Incentive Bonus (AIB) Plan for our NEOs. The intent of the AIB Plan is to reward high performance aligned with the Company’s strategic mission. NEOs, in addition to key corporate staff, are eligible to participate in the AIB Plan. Annual cash awards will be forfeited for employees who are terminated prior to the payout of such bonus under the AIB plan.

The bonus payouts under the AIB Plan are designed to incentivize achievement of the Company’s EBITDA target as set by our Board at the beginning of each fiscal year. The Company provided updated financial EBITDA guidance later in 2022, which was lower than the EBITDA target set by the Board for purposes of the AIB plan. While the Compensation Committee did not make any adjustments to the EBITDA target for purposes of the AIB plan, as a result, the target was not met and the executives would not have received a bonus. However, considering the Company’s challenges and leadership transitions, despite the Company’s underperformance, the Compensation Committee approved discretionary funding at approximately 50% of the budgeted bonus pool for annual incentive bonuses in recognition of performance efforts during a challenging year to retain ATI’s talent at all eligible levels.

Accordingly, the Compensation Committee approved bonus payouts to the NEOs consistent with the Company’s key corporate staff and other employees, as follows:

As of March 31, 2023 approximately 10.9 million shares of Common Stock were reserved for issuance under the 2021 Plan.

For 2022, the Compensation Committee granted restricted stock units and stock options to our NEOs, as follows:

The Compensation Committee decided on this mix of long-term incentives to balance numerous goals, including attracting, motivating, and retaining our NEOs, while aligning them with the long-term interests of our stockholders.

RSUs granted as part of the 2022 annual equity grant vest one-third on each of the first three anniversaries of the date of the grant. For Mr. Jordan, Mr. Oakes, Mr. Wahl and Mr. Zavalishin, stock options granted as part of the 2022 annual equity grant vest one-third on each of the first three anniversaries of the date of the grant. For Ms. Fong and Mr. Carlson, stock options granted as part of the 2022 annual equity grant vest one-fourth on each of the first four anniversaries of the date of the grant.

Prior to the Business Combination, Wilco Acquisition, LP adopted the Wilco Acquisition, LP 2016 Equity Incentive Plan (the “2016 Plan”), granting Incentive Common Units (“ICUs”), subject to time-based and performance-based vesting. In connection with the Business Combination, ICU holders received distributions of shares of common stock and restricted shares of common stock (“Restricted Shares”) from Wilco Acquisition, LP

based upon the distribution priorities under the Wilco Acquisition, LP limited partnership agreement. Any Restricted Shares are subject to certain vesting provisions of restricted stock agreements (“Restricted Stock Agreements”) executed by such holders and the terms of the 2021 Plan. See the Company’s Annual Report on Form 10-K for a description of the terms applicable to the restricted shares of common stock, and see the “Beneficial Ownership of Our Common Stock,” “Outstanding Equity Awards at Fiscal Year-End” and “Agreements with Executive Officers” herein for additional information on the outstanding shares of Common Stock and restricted shares of Common Stock held by named executive officers and directors.

The Company maintains a tax-qualified 401(k) savings plan (the “401(k) Plan”), in which all of our employees, including our NEOs, are eligible to participate. The 401(k) Plan allows participants to contribute up to 80% of base salary on a pre-tax basis (or on a post-tax basis, with respect to elective Roth deferrals) into individual retirement accounts, subject to any maximum annual limits set by the Internal Revenue Service. The Company provides for per pay period matches to employees of up to 50% of an employee’s first 6% of contributions to the 401(k) Plan. Participants are immediately, fully vested in their own contributions and any Company matches once eligible for match. Participants become eligible for the Company match after one year of service with the Company during which they performed at least 1,000 hours of service.

Our NEOs are eligible to receive the same employee benefits that are generally available to all of our full-time employees, subject to the satisfaction of certain eligibility requirements. This includes medical, dental and vision benefits, flexible spending accounts, short-term and long-term disability, and life insurance.

Our NEOs also receive certain additional perquisites, including tax preparation and planning and cell phone service reimbursement. We do not view perquisites or personal benefits as a significant component of our executive compensation program. But we have provided such benefits in limited circumstances where we believe it is appropriate to assist an NEO in the performance of their duties, to make our NEOs more efficient and effective, for security purposes, and for recruitment, motivation, and retention purposes.

The Company maintains a non-qualified deferred compensation plan (the “Supplemental Retirement Benefit Plan”) under which a select group of highly compensated employees are permitted to supplement contributions made under the 401(k) Plan by deferring up to 50% of their base salary. There is no corresponding Company match provided in the non-qualified plan. Any refunds for prior year contributions returned due to discrimination testing can be rolled into the non-qualified plan at 100%.

Many of our NEOs are parties to employment agreements with the Company that provide for certain severance benefits in certain circumstances as described below.

Under our Insider Trading Policy, our employees, including our NEOs and members of our Board, are prohibited from hedging or pledging our stock, engaging in short selling of our securities, trading in derivative securities of our Company, holding our securities in a margin account, or otherwise pledging them as collateral for a loan.

Section 162(m) of the Internal Revenue Code places a limit of $1 million in compensation per year on the amount public companies may deduct with respect to certain executive officers. When determining compensation for our NEOs, our Compensation Committee balances many factors, including the limitation on the Company’s ability to deduct compensation imposed by Section 162(m) in addition to market trends for similar roles and positions and determines compensation it believes is in the best interests of the Company’s stockholders’ long-term interests.

The Company follows ASC 718 for our stock-based compensation awards. ASC 718 requires us to measure, and recognize, the compensation expense for all share-based payment awards made to our employees and independent members of our Board, based on grant date fair value. This calculation is performed for accounting purposes and reported in the executive compensation tables included below in this proxy, even though the recipient of an equity award may never realize any value from the awards the recipient was granted.

Our Compensation Committee has reviewed our compensation policies and practices to assess whether they encourage our NEOs to take inappropriate risk. Our Compensation Committee believes that the Company’s compensation programs do not create risks that are reasonably likely to have a material adverse effect on the Company. The mix of fixed and variable compensation prevents undue focus on short-term results and is intended to align the long-term interests of our NEOs with those of our stockholders.

The section below contains information, both narrative and tabular, regarding the compensation paid to our NEOs for the fiscal year 2022.

To our knowledge, based solely on a review of the copies of the reports required pursuant to Section 16(a) of the Exchange Act that have been furnished to us and written representations that no other reports were required, during the fiscal year ended December 31, 2022, all Section 16(a) filing requirements applicable to our directors, executive officers, and greater than 10% beneficial owners have been met.

The following table provides information regarding equity and non-equity incentive plan-based awards granted to our NEOs for the year ended December 31, 2022. Except as set forth below, there were no other grants of equity to NEOs during 2022.

The following table provides information regarding all outstanding stock options held by each individual as of December 31, 2022.

The following table summarizes the number and market value of stock awards held by each NEO that vested during 2022.

The following table summarizes NEO non-qualified deferred compensation.

The Company has entered into employment agreements with Ms. Vitti, Mr. Kantz, Mr. Cox, Mr. Gregerson, Mr. Jordan, Ms. Tansey and Mr. Oakes. The material terms of these employment agreements are detailed below, including the potential payment upon termination, except for Mr. Zavalishin, Ms. Chafey and Mr. Wahl who each were no longer employed by the Company at the end of 2022 and thus their summaries detail what each was paid as a result of their departure.

The Company and Mr. Larsen did not have an employment agreement covering his services as Executive Chairman during part of 2021 and 2022.

The Company’s employment agreements with Ms. Vitti, Mr. Kantz, Mr. Cox, Mr. Gregerson, Mr. Jordan, Ms. Tansey and Mr. Oakes (the “Executive Employment Agreements”), provide for an initial term of three years that automatically renews for one-year terms thereafter, unless notice of non-renewal is provided 30 days before the renewal date, and a minimum base salary of $700,000 for Ms. Vitti, $490,000 for Mr. Cox, Mr. Gregerson and Ms. Tansey, and Mr. Jordan and $390,000 for Mr. Kantz and Mr. Oakes. In addition, the Executive Employment Agreements provide for annual target bonuses equal to 75% of base salary for Mr. Kantz, Mr. Cox, Mr. Gregerson, Mr. Jordan, Ms. Tansey and (as amended on June 20, 2022) Mr. Oakes. Ms. Vitti’s Executive Employment Agreement provides for annual target bonuses equal to 100% of base salary. The Executive Employment Agreements also provide for other standard benefits and perquisites, such as reimbursement of reasonable business expenses and entitlement to health and welfare benefits generally available to other executive employees, including vacation and sick leave, medical, dental, life and disability insurance benefits.

The Executive Employment Agreements provide that Ms. Vitti be granted long-term incentive equity awards from ATI for each of 2022, 2023 and 2024, that Mr. Cox be granted long-term incentive equity awards from ATI for each of 2023 and 2024, that Mr. Katz, Mr. Gregerson and Ms. Tansey be granted long-term incentive equity awards from ATI for 2023, that Mr. Jordan be granted long-term incentive equity awards from ATI in each of 2021, 2022 and 2023 and Mr. Oakes be granted incentive equity awards from ATI in 2021.

The aggregate grant-date value of such annual equity awards are to be $1,700,000 for Ms. Vitti in respect to each of 2022, 2023 and 2024, and $1,000,000 for Mr. Cox in 2023 and $500,000 in respect to 2024, and $500,000 for Mr. Gregerson and Ms. Tansey in respect of 2023, and $250,000 for Mr. Kantz and Mr. Oakes in respect of 2023, and $500,000 for Mr. Jordan in respect of 2022 and $750,000 in respect of 2023. Ms. Vitti’s agreement provides that fifty percent (50%) of the aggregate value of the equity awards in respect of 2022, 2023, and 2024 are to be granted in the form of restricted stock units and the remaining fifty percent (50%) is to be granted in the form of stock options; for Mr. Cox, his agreement provides that one hundred percent (100%) of the aggregate value of the equity awards in respect of 2023 and 2024 are to be granted in the form of restricted stock units; for Mr. Gregerson, his agreement provides that one hundred percent (100%) of the aggregate value of the equity awards in respect of 2023 are to be granted in the form of restricted stock units; for Ms. Tansey and Mr. Kantz, their agreements provide that fifty percent (50%) of the aggregate value of the equity awards in respect of 2023, are to be granted in the form of restricted stock units and the remaining fifty percent (50%) is to be granted in the form of stock options. The forms of equity awards in respect of subsequent years will be determined by ATI’s Compensation Committee after consultation with an external compensation consultant.

The equity awards are governed by the terms of the Executive Employment Agreements, the 2021 Plan, the Restricted Stock Agreements, and certain Restricted Stock Unit Award Agreements and Stock Option Award Agreements (the “Award Agreements”), as applicable. The equity awards in respect of fiscal year 2022 will vest in three equal annual installments over three years from the Closing Date of the Business Combination or date of grant, depending on the award, and vesting of equity awards in respect of subsequent years will be determined by the Company’s Compensation Committee after consultation with an external compensation consultant. With respect to years following 2023, Mr. Kantz, Mr. Gregerson, Ms. Tansey and Mr. Jordan will be eligible to receive equity awards on terms and conditions determined by the Company’s Compensation Committee after consultation with an external compensation consultant. With respect to years following 2024, Ms. Vitti and Mr. Cox will be eligible to receive equity awards on terms and conditions determined by the Company’s Compensation Committee after consultation with an external compensation consultant. Mr. Oakes is now eligible to receive equity awards on terms and conditions determined by the Company’s Compensation Committee after consultation with an external compensation consultant.

Under the terms of Ms. Vitti’s agreement, in the event of a termination without cause by the Company or a termination for good reason by Ms. Vitti, during the term of her Executive Employment Agreement and at any time other than within 24 months following a change in control, Ms. Vitti will receive (i) an amount equal to 1.5 times the sum of annual base salary and target bonus amount, payable in substantially equal installments over 18 month from termination; (ii) an annual bonus for the then-current fiscal year based on actual performance for such year, pro-rated from the first date of such fiscal year through Ms. Vitti’s last date of continued active employment, payable at the same time as annual bonuses are paid other senior executives of the Company; (iii) reimbursement of COBRA costs for a coverage period of 12 months, if elected, the employer and employee portion of any COBRA health and welfare premiums for a period equal to eighteen (18) months from the date of termination, or, if earlier, (x) the first date that Ms. Vitti is no longer eligible for COBRA, or (y) the first date that Ms. Vitti becomes eligible for health benefits from another employer; or (b) upon termination during the 24-month period following a Change in Control (i) an amount equal to 2.0 times the sum of (x) Ms. Vitti’s base salary and (y) Target Bonus, in a lump sum on the first payroll date, (ii) an annual bonus for the then-current fiscal year based on actual performance for such year, pro-rated from the first date of such fiscal year through Ms. Vitti’s last date of continued active employment, payable at the same time as annual bonuses are paid other senior executives of the Company, (iii) if elected, the employer and employee portion of any COBRA health and welfare premiums for a period equal to eighteen (18) months from the date of such termination, or, if earlier, (x) the first date that Ms. Vitti is no longer eligible for COBRA or (y) the first date that Ms. Vitti becomes eligible for health benefits from another employer, and (iv) all prior unvested grants of equity incentive compensation made to Ms. Vitti pursuant to the Company’s 2021 Equity Incentive Plan as of the date of such termination. Under the terms of the agreements, in the event of a termination without cause by the Company or a termination for good reason by Mr. Cox, Mr. Kantz, Mr. Gregerson, Mr. Jordan, Ms. Tansey or Mr. Oakes, during the term of their respective Executive Employment Agreements and at any time other than within 18 months following a change in control, each will receive (i) an amount equal to 1.25 times the sum of annual base salary and target bonus amount, payable in 15 monthly installments; (ii) a pro-rated annual bonus based on actual performance for the year in which termination occurs; (iii) reimbursement of COBRA costs for a coverage period of 12 months, and (iv) immediate vesting of any restricted shares received in connection with ICUs granted under the 2016 Plan. In the event of a termination of without cause by the Company or termination for good reason by Mr. Cox, Mr. Kantz, Mr. Gregerson, Mr. Jordan, Ms. Tansey or Mr. Oakes, within 18 months following a change in control, each are to receive (i) an amount equal to 1.5 times the sum of his annual base salary and target bonus amount, payable in a lump sum; (ii) a pro-rated annual bonus based on actual performance for the year in which termination occurs; (iii) reimbursement of COBRA costs for a coverage period of 12 months, and (iv) immediate vesting of any restricted shares received in connection with the ICUs granted under the 2016 Plan. Any such severance payments will be subject to applicable taxes and the executive’s execution and non-revocation of a general release of claims and continued compliance with restrictive covenant provisions. Any unvested RSUs and stock options are forfeited immediately upon termination of employment (for any reason), and any vested stock options are forfeited immediately upon termination for cause. Any vested options must be exercised prior to the earliest to occur of (i) the expiration date (which is 10 years after the grant date), (ii) 12 months after termination of employment due to death or disability, (iii) 90 days following termination of employment other than for death, disability, or termination for cause, or (iv) the date of termination for cause. Upon a change in control, (i) any awards under the Award Agreements are to be continued and or assumed by the Company or surviving company, or substituted by the surviving company with substantially similar terms for the outstanding awards, and (ii) and Restricted Shares are to vest immediately prior to the change in control. Additionally, if a participant’s employment or service is terminated upon or within 24 months following a change in control by ATI without cause or upon such other circumstances as determined by

the Compensation Committee, the unvested portion (if any) of all outstanding awards held by the participant will immediately vest (and, to the extent applicable, become exercisable) and be paid in full upon such termination, with any performance conditions deemed achieved (i) for any completed performance period, based on actual performance, or (ii) for any partial or future performance period, at the greater of the target level or actual performance, unless otherwise provided in an award agreement.

Most Executive Employment Agreements contain restrictive covenants generally prohibiting each executive from providing services to a competitor or soliciting employees or business contacts for 15 months following termination of employment, or for 18 months if the executive receives enhanced severance upon a qualifying termination within 18 months following a change in control. In addition, the Executive Employment Agreements mandate that the confidentiality obligations continue after termination of employment.

Any compensation payable under an Executive Employment Agreement, and any awards under the Award Agreements and Restricted Stock Agreements, are subject to recoupment under the 2021 Plan and applicable law, including the provisions of Section 945 of the Dodd-Frank Wall Street Reform and Consumer Protection Act and the rules, regulations and requirements adopted thereunder by the SEC and/or national securities exchange on which the Company’s shares are listed. Under the terms of the 2021 Plan, if after termination of employment the Committee determines in its discretion that the executive engaged in an act or omissions that would have warranted termination for cause, or after termination the executive violated any continuing obligation or duty in respect of the Company, such executive’s rights, payments and benefits with respect to an award are subject to cancellation, forfeiture and/or recoupment.

As defined in a substantively similar manner under the relevant agreements:

“Termination for cause” means termination of employment for (i) willful misfeasance or nonfeasance (including not following the reasonable written direction of the Board, any committee or the Company’s CEO (other than due to disability), or repeated intentional refusal to perform assigned duties (other than due to disability), which in each case continues uncured for 30 days after written notice; (ii) personally engaging in illegal conduct or any act of moral turpitude which reasonably could be expected to harm the Company; (iii) breaching in any material respect the Executive Employment Agreement (other than due to disability) which continues uncured for 30 days after written notice, other than a breach of confidentiality or restrictive covenants (which do not require written notice or opportunity to cure); or (iv) commencement of employment with another company without prior consent.

“Termination without cause” means the Company’s termination of the executive other than for cause or due to executive’s death or disability.

“Termination for good reason” means voluntary termination by executive if (i) there is a reduction in executive’s annual salary or percentage target bonus opportunity then in effect; (ii) the Company acts in any way that adversely affects employee’s participation in or materially reduce executive’s benefits under any benefit plan of the Company, except those changes generally affecting similarly situated employees; (iii) the Company materially breaches the terms of the Executive Employment Agreement; or (iv) there is a material diminution of executive’s job title, reporting relationship or job duties or responsibilities that are materially inconsistent with the position under the agreement; in each case provided that (y) executive notifies the Board in writing of any event constituting the basis for a termination for good reason within 30 days after their knowledge of the initial existence of the circumstance, and (z) the Company fails to cure such circumstance within 30 after such notice.

“Disability” means an executive’s inability to perform the essential duties, responsibilities, and functions of their position as a result of any mental or physical disability or incapacity for a length of time that the Company determines is sufficient to satisfy such obligations as it may have to provide leave under applicable family and medical leave laws and/or “reasonable accommodation” under applicable federal, state or local disability laws.

“Change in control” means (i) any person (other than the Company, any trustee or other fiduciary holding securities under any employee benefit plan of the Company, or any company owned, directly or indirectly, by the stockholders of the Company in substantially the same proportions as their ownership of shares of Common Stock), is or becomes the “beneficial owner” (as defined in Rule 13d-3 under the Exchange Act), directly or indirectly, of securities of the Company representing more than 50% of the combined voting power of the Company’s then outstanding securities, (ii) during any period of two consecutive years (the “Board Measurement Period”) individuals who at the beginning of such period constitute the Board and any new director (other than a director designated by a person who has entered into an agreement with the Company to effect a transaction described in paragraph

(i), (iii) or (iv) of this definition, or a director initially elected or nominated as a result of an actual or threatened election contest with respect to directors or as a result of any other actual or threatened solicitation of proxies by or on behalf of any person other than the Board) whose election by the Board or nomination for election by the Company’s stockholders was approved by a vote of at least two-thirds of the directors then still in office who either were directors at the beginning of the Board Measurement Period or whose election or nomination for election was previously so approved, cease for any reason to constitute at least a majority of the Board, (iii) merger or consolidation of the Company with any other corporation, other than a merger or consolidation which would result in the voting securities of the Company outstanding immediately prior thereto continuing to represent (either by remaining outstanding or by being converted into voting securities of the surviving entity) more than 50% of the combined voting power of the voting securities of the Company or such surviving entity outstanding immediately after such merger or consolidation (provided that a merger or consolidation effected to implement a recapitalization of the Company or similar transaction in which no Person other than those covered by the exceptions in (i) above acquires more than 50% of the combined voting power of the Company’s then outstanding securities (which is not a change in control), or (iv) the stockholders of the Company approve the consummation of the sale or disposition by the Company of all or substantially all of the Company’s assets other than (y) the sale or disposition of all or substantially all of the assets of the Company to a person(s) who beneficially own, directly or indirectly, more than 50% of the combined voting power of the outstanding voting securities of the Company at the time of the sale or (z) pursuant to a spinoff type transaction, directly or indirectly, of such assets to the stockholders of the Company.

Effective September 20, 2022, Diana Chafey stepped down from her positions as Chief Legal Officer of the Company.

Effective July 8, 2022, Joe Zavalishin stepped down from his positions as Chief Development Officer of the Company. The Company and Zavalishin have entered into a mutual release pursuant to which Zavalishin is eligible for the following payments and benefits: (i) 1.25x the sum of his base salary and target bonus in 2022, paid over 15 months from the date of termination; (ii) a prorated bonus for the current year, based on actual performance, paid at the time bonuses are paid to other employees; (iii) continued coverage of health benefits for up to 12 months, if elected; and (iv) the vesting of all unvested grants of equity compensation made to him pursuant to the Wilco Acquisition LP 2016 Equity Incentive Plan.

Effective December 16, 2022, Ray Wahl stepped down from his positions as Chief Operating Officer of the Company. The Company and Wahl have entered into a mutual release pursuant to which Wahl is eligible for the following payments and benefits: (i) 1.25x the sum of his base salary and bonus in 2022, paid over 15 months from the date of termination; (ii) a prorated bonus for the current year, based on actual performance, paid at the time bonuses are paid to other employees; (iii) continued coverage of health benefits for up to 12 months, if elected; and (iv) the vesting of all unvested grants of equity compensation made to him pursuant to the Wilco Acquisition LP 2016 Equity Incentive Plan.