Exhibit 10.4

Personal and Confidential
December 19, 2024
Tim Sides
Via e-mail
Re: Retention Bonus Agreement
Dear Tim Sides,
Acadia Management, a Delaware limited liability corporation (the “Company”), is pleased to offer you the opportunity to earn a cash retention bonus (the “Bonus”) on the terms and subject to the conditions set forth in this letter agreement (this “Agreement”).
If earned, the Bonus will be paid to you in a lump sum cash payment on the Company’s first regular pay date coincident with or next following the date that is 30 days after the earlier to occur of the Bonus Date or the effective date of the Release following an Involuntary Termination.
“Cause” will be determined in the Company’s discretion and shall mean that you (i) have engaged in gross negligence, willful misconduct, dishonesty, or fraud in the performance of your duties with respect to the Company or any of its affiliates, (ii) have breached any written agreement with the Company or any of its affiliates or policy or code of conduct established by the Company or any of its affiliates, (iii) have materially violated a material policy of the Company or its affiliates or otherwise engaged in conduct that is, or could reasonably be
6100 Tower Circle, Suite 1000 | Franklin, TN 37067
www.acadiahealthcare.com
Exhibit 10.4

expected to be, injurious to the Company or any of its affiliates, (iv) have failed to perform the material services required of you by the Company, or (v) have committed, been convicted of, plead no contest to or received adjudicated probation or deferred adjudication in connection with a felony or a crime involving fraud, dishonesty or moral turpitude.
“at will” nature of your employment (meaning either you or the Company may terminate your employment at any time and for any reason, or for no reason at all) or confers upon you the right to continue to be employed by the Company or any of its affiliates for any particular period of time. The Bonus will not be taken into account to increase any benefits or compensation provided, or continue coverage, under any other plan, program, policy or arrangement of the Company or any of its affiliates.
Please review this Agreement carefully and, if you agree with all the terms and conditions as specified above, please sign and date this Agreement in the space below and return the signed Agreement to Brittany Whitman that it is received by Brittany Whitman no later than January 17, 2025.
[Signature Page Follows]
6100 Tower Circle, Suite 1000 | Franklin, TN 37067
www.acadiahealthcare.com
Exhibit 10.4

Sincerely,
ACADIA Management
By:
Name: Brian Farley
Title: General Counsel
ACKNOWLEDGED AND AGREED:
Tim Sides
Date:
6100 Tower Circle, Suite 1000 | Franklin, TN 37067
www.acadiahealthcare.com
Exhibit 10.4

Personal and Confidential
August 6, 2025
Tim Sides (via email)
Re: Amendment to Retention Bonus Agreement
Dear Tim:
This letter seeks to modify that certain Retention Bonus Agreement dated December 19, 2024, between you and Acadia Management (the "Agreement").
Specifically, the Bonus (as defined in the Agreement) set forth in Paragraph 1 of the Agreement is hereby increased to $500,000, less applicable taxes, deductions and withholdings.
All other terms in the Agreement remain unchanged and in full force and effect. Please indicate your agreement to this modification by countersigning this letter.
Sincerely,
ACADIA Management
By:
Brian Farley
General Counsel
ACKNOWLEDGED AND AGREED:
Tim Sides
Date:
6100 Tower Circle, Suite 1000 | Franklin, TN 37067
www.acadiahealthcare.com