Contract

GUARANTOR ACKNOWLEDGMENT AND AGREEMENT Each of the undersigned consents and agrees to and acknowledges the terms of the foregoing Amendment No. 6 to Credit Agreement, dated as of February 27, 2009. Each of the undersigned specifically acknowledges the terms of and consent to the waivers set forth therein. Each of the undersigned further agrees that the obligations of each of the undersigned pursuant to the Closing Date Guaranty executed by each of the undersigned shall remain in full force and effect and be unaffected hereby. Each of the undersigned, by signing below, hereby waives and releases the Lender and its respective directors, officers, employees, attorneys, affiliates and subsidiaries from any and all claims, offsets, defenses and counterclaims of which any of the undersigned is aware, such waiver and release being with full knowledge and understanding of the circumstances and effect thereof and after having consulted legal counsel with respect thereto. EACH OF THE UNDERSIGNED WAIVES ANY RIGHT TO HAVE A JURY PARTICIPATE IN RESOLVING ANY DISPUTE, WHETHER SOUNDING IN CONTRACT, TORT OR OTHERWISE, AMONG ANY OF THE UNDERSIGNED, THE BORROWER AND/OR THE LENDER, ARISING OUT OF, IN CONNECTION WITH, RELATED TO, OR INCIDENTAL TO THE RELATIONSHIP ESTABLISHED AMONG THEM IN CONNECTION WITH THIS AGREEMENT, THE CREDIT AGREEMENT, THE NOTE OR OTHER RELATED WRITING, INSTRUMENT, DOCUMENT OR AGREEMENT EXECUTED OR DELIVERED IN CONNECTION HEREWITH OR THE TRANSACTIONS RELATED THERETO. [Remainder of page intentionally left blank.] IN WITNESS WHEREOF, each of the undersigned has duly executed and delivered this Guarantor Acknowledgement and Agreement as of the date first written above. DCA of Adel, LLC DCA of Aiken, LLC DCA of Barnwell, LLC DCA of Calhoun, LLC DCA of Camp Hill, LLC DCA of Central Valdosta, LLC DCA of Chesapeake, LLC DCA of Columbus, LLC DCA of Edgefield, LLC DCA of Fitzgerald, LLC DCA of Hyattsville, LLC DCA of Lemoyne, Inc. DCA of Manahawkin, Inc. DCA of Mechanicsburg, LLC DCA of North Baltimore, LLC DCA of Norwood, LLC DCA of Rockville, LLC DCA of Royston, LLC DCA of Selinsgrove, LLC DCA of So. Ga., LLC DCA of South Aiken, LLC DCA of Warsaw, LLC DCA of Wellsboro, Inc. Keystone Kidney Care, Inc. York Realty Managers, LLC /s/ Stephen W. Everett By:-------------------------------------- Name: Stephen W. Everett Title: President of each of the foregoing Guarantors