Waiver and Modification Agreement


    Exhibit
      10.1

    
 

    WAIVER
      AND MODIFICATION 

    


    This
      waiver and modification (this “Waiver”) is made and entered into by the
      undersigned executive (the “Executive”) and Express Scripts, Inc. (“ESI”)
      effective as of December 15, 2006.

     

    RECITALS:

     

    A.     The
      Executive
      is an employee and executive officer of Express Scripts, Inc. (“ESI”), and is a
      party to an Executive Employment Agreement with ESI (the “Employment
      Agreement”).

     

    B.     On
      December 12, 2006, ESI’s Board of Directors (the “Board”) authorized ESI to make
      an offer to acquire all of the outstanding common stock of Caremark Rx, Inc.
      (“Caremark”), which offer may be revised or adjusted by the Board or the
      Transaction Committee of the Board (the “Offer”).

     

    C.     The
      Executive
      has received one or more Awards under the Express Scripts, Inc. 2000 Long Term
      Incentive Plan, as amended (the “Plan”), each of which is subject to the
      specific terms of such Award and the Plan.

     

    D.     Pursuant
      to
      Section 2(g)(iii) of the Plan a “Change in Control” is deemed to occur upon a
      merger or certain other “Business Combinations” (as defined in the plan), unless
      each of the conditions in Subsections (A), (B) and (C) of Section 2(g)(iii)
      are
      satisfied. The condition in Subsection 2(g)(iii)(A) is as follows:

     

    “all
      or
      substantially all of the individuals and entities who were the beneficial
      owners, respectively, of the Outstanding Company Common Stock and Outstanding
      Company Voting Securities immediately prior to such Business Combination
      beneficially own, directly or indirectly, more than 50% of, respectively, the
      then outstanding shares of common stock and the combined voting power of the
      then outstanding voting securities entitled to vote generally in the election
      of
      directors or other governing body, as the case may be, of the entity resulting
      from such Business Combination (including, without limitation, an entity that
      as
      a result of such transaction owns the Company through one or more
      subsidiaries)”.

     

    E.  Because
      a
      successful transaction resulting from the Offer could ultimately be structured
      in a variety of ways, it is possible that a Business Combination could result
      in
      the stockholders of Caremark holding greater than 50% of the common stock of
      the
      surviving entity, even though ESI’s Board and management remain in control of
      the surviving entity following such Business Combination, thus constituting
      a
      Change in Control under Section 2(g)(iii) of the Plan and the Employment
      Agreement (which specifically adopts the Change in Control definition under
      the
      Plan).

     

    NOW,
      THEREFORE, in order to facilitate a possible transaction as described above,
      and
      for other good and valuable consideration, the parties hereby agree as
      follows:

     

    1.     Any
      Business
      Combination involving ESI and Caremark resulting directly or indirectly from
      the
      Offer, after which at least a majority of the members of the board of directors
      or other governing body of the entity resulting from such Business Combination
      were members of the Board at the time of the execution of the initial agreement
      setting forth the terms of the Business Combination, shall not constitute a
      Change in Control under Section 2(g)(iii) of the Plan (including as it would
      apply to the Employment Agreement).

     

    2.     The
      appropriate agreement or notice with respect to each Award granted to the
      Executive, and the Employment Agreement, are each hereby amended and modified
      to
      reflect the foregoing. 

     

    IN
      WITNESS WHEREOF, this Waiver and Modification has been duly executed and
      delivered as of the effective date set forth above.

     

    
      	
              Executive:

               

              ________________________________________

              Name:_________________________________________
                     

            	 	
              Express
                Scripts, Inc.

               

              By:__________________________________________ 

              Name: _______________________________________

              Title:
                ________________________________________