Exhibit 4.1k

TENTH SUPPLEMENTAL INDENTURE

THIS TENTH SUPPLEMENTAL
INDENTURE dated as of December , 2009 among CRC Health Corporation, a Delaware corporation (the Company), the Guarantors, Adirondack Leadership Expeditions, LLC, a Delaware limited liability company
(the New Guarantor) and U.S. Bank National Association, as trustee (the Trustee).

WHEREAS, the Company and the Guarantors have heretofore executed and delivered to the Trustee an indenture dated as of February 6, 2006 (the Indenture), providing for the issuance of $200 million aggregate principal
amount of the Companys 10.75% Senior Subordinated Notes due 2016 (the Notes), as supplemented by the First Supplemental Indenture, dated as of July 7, 2006 (the First Supplemental Indenture), the
Second Supplemental Indenture, dated as of September 28, 2006 (the Second Supplemental Indenture), the Third Supplemental Indenture, dated as of October 24, 2006 (the Third Supplemental Indenture), the
Fourth Supplemental Indenture, dated as of November 17, 2006 (the Fourth Supplemental Indenture), the Fifth Supplemental Indenture, dated as of April 27, 2007 (the Fifth Supplemental Indenture), the
Sixth Supplemental Indenture, dated as of July 26, 2007 (the Sixth Supplemental Indenture), the Seventh Supplemental Indenture, dated as of May 29, 2008 (the Seventh Supplemental Indenture), the Eighth
Supplemental Indenture, dated as of November 18, 2008 (the Eighth Supplemental Indenture) and the Ninth Supplemental Indenture, dated as of April 27, 2009 (the Ninth Supplemental Indenture);

WHEREAS, the Company and the Guarantors propose to further amend and supplement the Indenture to join the New Guarantor, a
direct or indirect subsidiary of the Company, as a party to the Indenture, as a Guarantor thereunder;

WHEREAS, pursuant to
Section 8.01 of the Indenture, the Company and the Trustee may amend, waive or supplement the Indenture, the Notes or the Guarantees without the consent of any Holders to make any change that would provide additional rights or benefits to the
holders of Notes or that does not adversely affect the legal rights under the Indenture of any such holder;

WHEREAS, the
Company, each Guarantor and the New Guarantor have been authorized by their respective board of directors, managers, members, partners, or general partners, as applicable, to enter into this Tenth Supplemental Indenture;

WHEREAS, all other acts and proceedings required by law, by the Indenture and by the respective certificates of incorporation, certificates
of formation, limited liability company agreements, partnership agreements, limited partnership agreements, by-laws and other organizational documents of the Company, each Guarantor and the New Guarantor to make this Tenth Supplemental Indenture a
valid and binding agreement for the purposes expressed herein, in accordance with its terms, have been duly performed;

WHEREAS, pursuant to Section 8.06 of the Indenture, the Trustee is authorized to execute and deliver this Tenth Supplemental Indenture;

WHEREAS, the Company hereby requests that the Trustee execute and deliver this Tenth Supplemental Indenture;



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NOW, THEREFORE, for in consideration of the premises herein contained and in order to effect
the proposed amendment to join the New Guarantor to the Indenture pursuant to Section 8.01 of the Indenture, the Company, the New Guarantor and the Guarantors agree with the Trustee as follows:

ARTICLE I

Amendment of Indenture

1.1. Amendment of Indenture. As of the date hereof, this Tenth Supplemental
Indenture amends the Indenture by joining the New Guarantor as parties to the Indenture, as a Guarantor thereunder.

1.2.
Execution and Delivery of Note Guarantee. Upon the effectiveness of this Tenth Supplemental Indenture, New Guarantor agrees that a notation of its Guarantee substantially in the form attached as Exhibit G to the Indenture, will be endorsed by
a duly authorized officer of New Guarantor on each Note authenticated and delivered by the Trustee under the Indenture.

ARTICLE II

Miscellaneous Provisions

2.1. Instruments to be Read Together. This Tenth Supplemental Indenture is an indenture supplemental to and in implementation of the
Indenture, and said Indenture, the First Supplemental Indenture, the Second Supplemental Indenture, the Third Supplemental Indenture the Fourth Supplemental Indenture, the Fifth Supplemental Indenture, the Sixth Supplemental Indenture, the Seventh
Supplemental Indenture, the Eighth Supplemental Indenture, the Ninth Supplemental Indenture and this Tenth Supplemental Indenture shall henceforth be read together.

2.2. Confirmation. The Indenture as amended and supplemented by the First Supplemental Indenture, the Second Supplemental Indenture, the Third Supplemental Indenture, the Fourth Supplemental
Indenture, the Fifth Supplemental Indenture, the Sixth Supplemental Indenture, the Seventh Supplemental Indenture, the Eighth Supplemental Indenture, the Ninth Supplemental Indenture and further amended and supplemented by this Tenth Supplemental
Indenture is in all respects confirmed and preserved.

2.3. Terms Defined. Capitalized terms used herein without
definition shall have the meanings assigned to them in the Indenture.

2.4. Counterparts. This Tenth Supplemental
Indenture may be signed in any number of counterparts each of which so executed shall be deemed to be an original, but all such counterparts shall together constitute but one and the same instrument.

2.5. Effect of Headings. The section headings herein are for convenience only and shall not affect the construction hereof.

2.6. Effectiveness. The provisions of this Tenth Supplemental Indenture will take effect immediately upon execution
thereof by the parties hereto.



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2.7. Trust Indenture Act Controls. If any provision of this Tenth Supplemental
Indenture limits, qualifies or conflicts with another provision that is required by or deemed to be included in this Tenth Supplemental Indenture by the Trust Indenture Act, the required or incorporated provision shall control.

2.8. Governing Law. THIS TENTH SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE
OF NEW YORK, AS APPLIED TO CONTRACTS MADE AND PERFORMED WITHIN THE STATE OF NEW YORK.

2.9. Trustee. The Trustee
makes no representations as to the validity or sufficiency of this Ninth Supplemental Indenture. The recitals and statements herein are deemed to be those of the Company, the Guarantors and the New Guarantor and not of the Trustee.

[The remainder of this page is intentionally left blank.]



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IN WITNESS WHEREOF, the undersigned have executed this Tenth Supplemental Indenture this
 day of December, 2009.



| |  |  |  |                        |  |                               
| |  |  |  | ---------------------- |  | ------------------------------
| |  |  |  | CRC HEALTH CORPORATION
| |  |  | 
| |  |  |  | By:                    |  |                               
| |  |  |  |                        |  | Name: Kevin Hogge             
| |  |  |  |                        |  | Title: Chief Financial Officer



[Signature Page to Tenth Supplemental Indenture]



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| |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |  |  |  | 
| |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  |  |  | 
| |  | CORPORATE SUBSIDIARIES:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |  | 
| |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
| |  | 4therapy.com NETWORKADVANCED TREATMENT SYSTEMS,
INC. ATS OF CECIL COUNTY, INC. ATS
OF DELAWARE, INC. ATS OF NORTH CAROLINA, INC. BATON ROUGE TREATMENT CENTER, INC. BGI OF BRANDYWINE, INC. BOWLING GREEN INN OF PENSACOLA, INC. BOWLING
GREEN INN OF SOUTH DAKOTA, INC. CAPS OF VIRGINIA, INC. CARTERSVILLE CENTER, INC. COMPREHENSIVE ADDICTION PROGRAMS, INC. CORAL HEALTH SERVICES, INC. CRC ED TREATMENT,
INC. CRC HEALTH OREGON, INC. CRC
HEALTH TENNESSEE, INC. CRC HEALTH MANAGEMENT, INC. CRC WEIGHT MANAGEMENT, INC. CRC CALIFORNIA RD, INC. GALAX TREATMENT CENTER, INC. GREENBRIER TREATMENT
CENTER, INC. JAYCO ADMINISTRATION, INC. KANSAS CITY TREATMENT CENTER, INC. |  | 

| |  |        |  |                         |  | 
| |  | ------ |  | ----------------------- |  | 
| |  |        | 
| |  | By:    |  |                         |  | 
| |  | Name:  |  | Kevin Hogge             |  | 
| |  | Title: |  | Chief Financial Officer |  | 



[Signature Page to Tenth Supplemental Indenture]



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| |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |  |  |  | 
| |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  |  |  | 
| |  | CORPORATE SUBSIDIARIES (cont.):                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |  | 
| |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
| |  | MINERAL COUNTY TREATMENT CENTER, INC. MWB ASSOCIATES-MASSACHUSETTS, INC. SAN DIEGO HEALTH ALLIANCE SHELTERED LIVING INCORPORATED SIERRA TUCSON INC. SOBER LIVING BY THE SEA, INC. SOUTHERN WEST VIRGINIA TREATMENT CENTER, INC. SOUTHWEST ILLINOIS TREATMENT CENTER, INC. STONEHEDGE CONVALESCENT CENTER, INC. TRANSCULTURAL
HEALTH DEVELOPMENT, INC. TREATMENT ASSOCIATES, INC. VIRGINIA TREATMENT CENTER, INC. VOLUNTEER TREATMENT CENTER, INC. WCHS OF COLORADO (G), INC. WCHS, INC. WHEELING TREATMENT CENTER, INC. WHITE DEER REALTY,
LTD. WHITE DEER RUN, INC. WICHITA
TREATMENT CENTER INC. WILLIAMSON TREATMENT CENTER, INC. WILMINGTON TREATMENT CENTER, INC. |  | 

| |  |        |  |                         |  | 
| |  | ------ |  | ----------------------- |  | 
| |  |        | 
| |  | By:    |  |                         |  | 
| |  | Name:  |  | Kevin Hogge             |  | 
| |  | Title: |  | Chief Financial Officer |  | 



[Signature Page to Tenth Supplemental Indenture]



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| |  |                                                                                                                                                                                                                                                                                                                                                                                                                           |  |  |  | 
| |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  |  |  | 
| |  | CORPORATE SUBSIDIARIES (cont.):                                                                                                                                                                                                                                                                                                                                                                                           |  | 
| |  |                                                                                                                                                                                                                                                                                                                                                                                                                          
| |  | ASPEN EDUCATION GROUP, INC. ASPEN YOUTH, INC. AYS MANAGEMENT, INC.
AHS OF IDAHO, INC. CAMP HUNTINGTON, INC. SUWS OF THE CAROLINAS, INC. WILDERNESS THERAPY PROGRAMS, INC. MOUNT BACHELOR EDUCATIONAL CENTER, INC. NEW LEAF ACADEMY, INC. NORTHSTAR CENTER, INC.
SUNHAWK ACADEMY OF UTAH, INC. TALISMAN SCHOOL,
INC. TEXAS EXCEL ACADEMY, INC. TURN-ABOUT RANCH, INC. YOUTH CARE OF UTAH, INC. LONE STAR EXPEDITIONS, INC. |  | 

| |  |        |  |                         |  | 
| |  | ------ |  | ----------------------- |  | 
| |  |        | 
| |  | By:    |  |                         |  | 
| |  | Name:  |  | Kevin Hogge             |  | 
| |  | Title: |  | Chief Financial Officer |  | 



[Signature Page to Tenth Supplemental Indenture]



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| |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |  |  |  | 
| |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |  |  |  | 
| |  | LIMITED LIABILITY COMPANY SUBSIDIARIES:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
| |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
| |  | ACADEMY OF THE SIERRAS, LLC ASPEN ACHIEVEMENT ACADEMY, LLC FOUR CIRCLES RECOVERY CENTER, LLC OUTBACK THERAPEUTIC EXPEDITIONS, LLC PASSAGES TO RECOVERY, LLC TALISMAN SUMMER CAMP, LLC ASPEN RANCH,
LLC BROMLEY BROOK SCHOOL, LLC CEDARS
ACADEMY, LLC COPPER CANYON ACADEMY, LLC ISLAND VIEW RESIDENTIAL TREATMENT CENTER, LLC NEW LEAF ACADEMY OF NORTH CAROLINA, LLC ASPEN INSTITUTE FOR BEHAVIORAL ASSESSMENT, LLC OAKLEY SCHOOL, LLC SWIFT RIVER ACADEMY, L.L.C. PHOENIX OUTDOOR, LLC STRUCTURE HOUSE, LLC CRC WISCONSIN RD, LLC BAYSIDE MARIN, LLC
CRC HOLDINGS, LLC LOAN ADMINISTRATION,
LLC LOAN HOLDINGS, LLC BECKLEY
TREATMENT CENTER, LLC CHARLESTON TREATMENT CENTER LLC CLARKSBURG TREATMENT CENTER, LLC EAST INDIANA TREATMENT CENTER, LLC EVANSVILLE TREATMENT CENTER, LLC HUNTINGTON
TREATMENT CENTER, LLC INDIANAPOLIS TREATMENT CENTER, LLC NATIONAL SPECIALTY CLINICS, LLC PARKERSBURG TREATMENT CENTER, LLC RICHMOND TREATMENT CENTER, LLC SOUTHERN INDIANA
TREATMENT CENTER, LLC ADIRONDACK LEADERSHIP EXPEDITIONS, LLC |  | 

| |  |        |  |                         |  | 
| |  | ------ |  | ----------------------- |  | 
| |  |        | 
| |  | By:    |  |                         |  | 
| |  | Name:  |  | Kevin Hogge             |  | 
| |  | Title: |  | Chief Financial Officer |  | 



[Signature Page to Tenth Supplemental Indenture]



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SAN DIEGO TREATMENT SERVICESBy:

Jayco Administration, Inc.Its:

PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial OfficerBy:

Treatment Associates, Inc.Its:

PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial Officer




[Signature Page to Tenth Supplemental Indenture]



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CALIFORNIA TREATMENT SERVICESBy:

Jayco Administration, Inc.Its:

PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial OfficerBy:

Treatment Associates, Inc.Its:

PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial Officer




[Signature Page to Tenth Supplemental Indenture]



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MILWAUKEE HEALTH SERVICES SYSTEMBy:

WCHS, Inc.Its:

PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial OfficerBy:

Coral Health Services, Inc.Its:

PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial Officer




[Signature Page to Tenth Supplemental Indenture]



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THE CAMP RECOVERY CENTERS, L.P.By:

CRC Recovery, Inc.Its:

General PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial OfficerBy:

CRC Health CorporationIts:

Limited PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial Officer




[Signature Page to Tenth Supplemental Indenture]



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STONEHEDGE CONVALESCENT CENTER LIMITED PARTNERSHIPBy:

Stonehedge Convalescent Center, Inc.Its:

General PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial OfficerBy:

Comprehensive Addiction Programs, Inc.Its:

Limited PartnerBy:Name:

Kevin HoggeTitle:

Chief Financial Officer




[Signature Page to Tenth Supplemental Indenture]



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U.S. BANK NATIONAL ASSOCIATION, as TrusteeBy:Name:Title:




[Signature Page to Tenth Supplemental Indenture]