Exhibit 10.1

Amendment No. 1 to Tax Sharing Agreement

       This Amendment No. 1 to Tax Sharing Agreement is made effective as of
June 9, 2005.

BACKGROUND

       A.     As of December 1, 2003, Genesis HealthCare Corporation, a
Pennsylvania corporation (“GHC”), and NeighborCare, Inc. (f/k/a Genesis Health
Ventures, Inc.), a Delaware corporation (“NeighborCare”), entered a Tax Sharing
Agreement (“Tax Sharing Agreement”).    

        B.     GHC and NeighborCare now desire to amend the Tax Sharing
Agreement as set forth in this Amendment No. 1 (“Amendment”).

AGREEMENT

       NOW THEREFORE, in consideration of the foregoing and the mutual promises
set forth in this Amendment, and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties hereto,
intending to be legally bound, hereby agree that the Tax Sharing Agreement is
amended as follows:

1. Section 7(a)(iv) of the Tax Sharing agreement is modified by replacing 40
percent with 70 percent.    

2. No changes or amendments will be made by NeighborCare or its successors to
any combined Returns as defined in the Tax Sharing Agreement for periods ending
on or before September 30, 2001 without the consent of Genesis.    

3. In the event of a Change in Control of NeighborCare, Genesis is granted the
joint right to represent members of combined Returns with respect to any tax
proceeding directly relating to the NOL available to Genesis. Pursuant to this
joint right, neither party will file any amended tax returns, enter any
settlement agreement with the Internal Revenue Service, or take any other action
that could be reasonably expected to have an adverse impact on the other without
the other’s consent, such consent not to be unreasonably withheld or delayed. A
“Change of Control” will be deemed to have occurred any time at which
individuals who, as of the date of this agreement, constitute the Board of
NeighborCare, Inc. (the “Incumbent Board”) cease for any reason to constitute at
least a majority of the Board; provided, however, that any individual becoming a
director subsequent to the date hereof whose election, or nomination for
election by the Company’s shareholders, was approved by a vote of at least a
majority of the directors then comprising the Incumbent Board shall be
considered as though such individual were a member of the Incumbent Board, but
excluding, for this purpose, any such individual whose initial assumption of
office occurs as a result of an actual or threatened election contest with
respect to the election or removal of directors or other actual or threatened
solicitation of proxies or consents by or on behalf of a person other than the
Board.    

4. Capitalized terms not otherwise defined in this Amendment have the meaning
defined in the Tax Sharing Agreement.

       IN WITNESS WHEREOF, the parties hereto, intending to be legally bound,
have duly executed this Amendment as of the day and year first written above.

NEIGHBORCARE, INC. GENESIS HEALTHCARE CORPORATION     By: /s/ John J.
Arlotta                By: /s/ George V. Hager, Jr.                  John
Arlotta   George V. Hager, Jr.   Chairman, President and Chief Executive Officer
  Chairman and Chief Executive Officer

 

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