Acadia Healthcare Company, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 14A

(Rule 14a-101)

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the Securities

Exchange Act of 1934 (Amendment No. )

Check the appropriate box:

(Name of Registrant as Specified in its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

March 25, 2026

TO OUR STOCKHOLDERS:

You are cordially invited to attend the 2026 Annual Meeting of Stockholders (the “Annual Meeting”) of Acadia Healthcare Company, Inc., to be held on Wednesday, May 6, 2026, at 8:00 a.m. (Central Time), at our executive offices located at 4020 Aspen Grove Drive, Suite 900, Franklin, Tennessee 37067. The matters to be acted upon at the Annual Meeting are more fully described in the accompanying Proxy Statement and related materials.

In accordance with rules adopted by the Securities and Exchange Commission, we are mailing to many of our stockholders a Notice of Internet Availability of Proxy Materials instead of a paper copy of the Proxy Statement and our 2025 Annual Report to Stockholders. The Notice of Internet Availability of Proxy Materials contains instructions on how stockholders can access the proxy documents over the internet as well as how stockholders can receive a paper copy of our proxy materials, including the Proxy Statement, the 2025 Annual Report to Stockholders and a form of proxy card.

It is important that your shares be represented at the Annual Meeting. Whether or not you plan to attend the Annual Meeting, please vote by proxy as soon as possible by following the instructions located in the Notice of Internet Availability of Proxy Materials sent to you or in the Proxy Statement. If you attend the Annual Meeting, you may withdraw your proxy and vote your shares personally.

We look forward to your attendance at the Annual Meeting.

Sincerely,

/s/ Debra K. Osteen

Debra K. Osteen

Chief Executive Officer and Director

YOUR VOTE IS IMPORTANT.

PLEASE COMPLETE, DATE, SIGN AND RETURN THE ENCLOSED PROXY CARD

AS PROMPTLY AS POSSIBLE.

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

To Be Held May 6, 2026

TO OUR STOCKHOLDERS:

The 2026 Annual Meeting of Stockholders (the “Annual Meeting”) of Acadia Healthcare Company, Inc. will be held on Wednesday, May 6, 2026, at 8:00 a.m. (Central Time), at our executive offices located at 4020 Aspen Grove Drive, Suite 900, Franklin, Tennessee 37067.

The Annual Meeting is being convened for the following purposes:

The matters to be acted upon at the Annual Meeting are more fully described in the Proxy Statement and related materials. Please read the materials carefully.

The Board of Directors has fixed the close of business on March 9, 2026 as the record date for determining stockholders entitled to notice of and to vote at the Annual Meeting or any adjournments or postponements thereof.

Dated: March 25, 2026

By order of the Board of Directors,

/s/ Debra K. Osteen

Debra K. Osteen

Chief Executive Officer and Director

IMPORTANT

WHETHER OR NOT YOU PLAN TO ATTEND THE ANNUAL MEETING, TO ASSURE THE PRESENCE OF A QUORUM, PLEASE COMPLETE, DATE, SIGN AND RETURN THE ENCLOSED PROXY CARD AS PROMPTLY AS POSSIBLE. IF YOU ATTEND THE MEETING AND WISH TO VOTE YOUR SHARES PERSONALLY, YOU MAY DO SO AT ANY TIME BEFORE THE PROXY IS EXERCISED.

TABLE OF CONTENTS

NOTE TO READERS

Unless the context otherwise requires, all references herein to “Acadia,” the “Company,” “we,” “us” or “our” mean Acadia Healthcare Company, Inc. and its consolidated subsidiaries. Acadia Healthcare Company, Inc. is a holding company whose direct and indirect subsidiaries own and operate acute inpatient psychiatric facilities, specialty treatment facilities, comprehensive treatment centers, residential treatment centers and facilities providing outpatient behavioral healthcare services to serve the behavioral healthcare and recovery needs of communities throughout the United States (the “U.S.”) and Puerto Rico. The terms “facilities,” “centers,” “clinics,” and “hospitals” refer to entities owned, operated, or managed by subsidiaries of Acadia Healthcare Company, Inc. References herein to “employees” refer to employees of subsidiaries of Acadia Healthcare Company, Inc.

i