Sec Form 4 Filing - BAIN CAPITAL INVESTORS LLC @ Acadia Healthcare Company, Inc. - 2015-08-10

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person BAIN CAPITAL INVESTORS LLC 2. Issuer Name and Ticker or Trading Symbol Acadia Healthcare Company, Inc. [ ACHC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner _____ Officer (give title below) X __ Other (specify below) Member of 10% Owner Group (Last) (First) (Middle) JOHN HANCOCK TOWER, 200 CLARENDON STREET 3. Date of Earliest Transaction (MM/DD/YY) 08/10/2015 (Street) BOSTON, MA02116 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, par value $0.01 08/10/2015 J( 9 ) 42,778 D $ 0 5,803,339 I See Footnotes ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) ( 8 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other BAIN CAPITAL INVESTORS LLC JOHN HANCOCK TOWER 200 CLARENDON STREET BOSTON, MA02116 Member of 10% Owner Group BCIP Associates III JOHN HANCOCK TOWER 200 CLARENDON STREET BOSTON, MA02116 Member of 10% Owner Group BCIP Associates III, LLC JOHN HANCOCK TOWER, 200 CLARENDON STREET BOSTON, MA02116 Member of 10% Owner Group BCIP Associates III-B JOHN HANCOCK TOWER 200 CLARENDON STREET BOSTON, MA02116 Member of 10% Owner Group BCIP Associates III-B, LLC JOHN HANCOCK TOWER, 200 CLARENDON STREET BOSTON, MA02116 Member of 10% Owner Group BCIP Trust Associates III JOHN HANCOCK TOWER 200 CLARENDON STREET BOSTON, MA02116 Member of 10% Owner Group BCIP T Associates III, LLC JOHN HANCOCK TOWER, 200 CLARENDON STREET BOSTON, MA02116 Member of 10% Owner Group BCIP Trust Associates III-B JOHN HANCOCK TOWER 200 CLARENDON ST. BOSTON, MA02116 Member of 10% Owner Group BCIP T Associates III-B, LLC JOHN HANCOCK TOWER, 200 CLARENDON STREET BOSTON, MA02116 Member of 10% Owner Group BCIP Associates-G JOHN HANCOCK TOWER 200 CLARENDON STREET BOSTON, MA02116 Member of 10% Owner Group Signatures Christopher Gordon 08/12/2015 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Bain Capital Investors, LLC ("BCI") is the general partner of Bain Capital Partners VIII, L.P. ("BCP VIII"), which is the general partner of Bain Capital Fund VIII, L.P. ("BCF VIII"), which is the sole member of Bain Capital Fund VIII, LLC ("Fund VIII"). As a result, BCI, BCP VIII and BCF VIII may be deemed to share voting and dispositive power with respect to all of the shares of Common Stock held by Fund VIII. Each of BCI, BCP VIII and BCF VIII disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. ( 2 )BCI is the general partner of BCP VIII, which is the general partner of Bain Capital VIII Coinvestment Fund, L.P. ("BC VIII-CO"), which is the sole member of Bain Capital VIII Coinvestment Fund, LLC ("Fund VIII-CO"). As a result, BCI, BCP VIII and BC VIII-CO may be deemed to share voting and dispositive power with respect to all of the shares of Common Stock held by Fund VIII-CO. Each of BCI, BCP VIII and BC VIII-CO disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. ( 3 )BCI is also the general partner of Bain Capital (CR), L.P. ("BC CR"). As a result, BCI may be deemed to share voting and dispositive power with respect to all of the shares of Common Stock held by BC CR. BCI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. ( 4 )BCI is also the managing partner of BCIP Associates III ("BCIPA III"), which is the manager of BCIP Associates III, LLC ("BCIP III"). As a result, BCI and BCIPA III may be deemed to share voting and dispositive power with respect to all of the shares of Common Stock held by BCIP III. Each of BCI and BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. ( 5 )BCI is also the managing partner of BCIP Associates III-B ("BCIPA III-B"), which is the manager of BCIP Associates III-B, LLC ("BCIP III-B"). As a result, BCI and BCIPA III-B may be deemed to share voting and dispositive power with respect to all of the shares of Common Stock held by BCIP III-B. Each of BCI and BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. ( 6 )BCI is also the managing partner of BCIP Trust Associates III ("BCIPTA III"), which is the manager of BCIP T Associates III, LLC ("BCIPT III"). As a result, BCI and BCIPTA III may be deemed to share voting and dispositive power with respect to all of the shares of Common Stock held by BCIPT III. Each of BCI and BCIPTA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. ( 7 )BCI is also the managing partner of BCIP Trust Associates III-B ("BCIPTA III-B"), which is the manager of BCIP T Associates III-B, LLC ("BCIPT III-B"). As a result, BCI and BCIPTA III-B may be deemed to share voting and dispositive power with respect to all of the shares of Common Stock held by BCIPT III-B. Each of BCI and BCIPTA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. ( 8 )BCI is also the managing partner of BCIP Associates-G ("BCIP G" and together with Fund VIII, Fund VIII-CO, BC CR, BCIP III, BCIP III-B, BCIPT III and BCIPT III-B, the "Bain Entities"). As a result, BCI may be deemed to share voting and dispositive power with respect to all of the shares of Common Stock held by BCIP-G. BCI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. ( 9 )On August 10, 2015, the Bain Entities distributed 42,778 shares of Common Stock to one or more members and partners of the Bain Entities in connection with certain charitable gifts made by such members or partners on August 10, 2015.

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