Document:

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                                                                    EXHIBIT 10.8

                      PATIENT ASSISTANCE PROGRAM AGREEMENT

                                  BY AND AMONG

                               MERCK & CO., INC.,

                     MERCK PATIENT ASSISTANCE PROGRAM, INC.

                                       AND

                          MEDCO HEALTH SOLUTIONS, INC.

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                      PATIENT ASSISTANCE PROGRAM AGREEMENT

     THIS PATIENT ASSISTANCE PROGRAM AGREEMENT (this "Agreement"), dated as of
June 28, 2002, between Merck & Co., Inc., a New Jersey corporation ("Merck"),
Merck Patient Assistance Program, Inc., a New Jersey nonprofit corporation (the
"Foundation"), and Medco Health Solutions, Inc., a Delaware corporation
("Medco"; Merck, the Foundation and Medco each being referenced herein
individually as a "Party," and collectively as the "Parties"). Capitalized terms
used herein but not otherwise defined herein shall have the meaning ascribed to
such terms in the Master Separation and Distribution Agreement to be entered
into between Merck and Medco.

         WHEREAS, the Board of Directors of Merck has determined that it is
appropriate and desirable for Merck to separate the Medco Group from the Merck
Group (the "Separation");

         WHEREAS, in connection with the foregoing, Merck and Medco intend to
enter into a Master Separation Agreement, which will provide, among other
things, for the Separation, the IPO of Medco Common Stock, the declaration of
the Merck Dividend immediately after the IPO Closing Date, the subsequent
Distribution of all the Medco Common Stock then owned by Merck to the holders of
Merck common stock, and the execution and delivery of certain other agreements
in order to facilitate and provide for the foregoing;

         WHEREAS, the Foundation has instituted a Patient Assistance Program
(the "General Program") to help provide access to Merck Products and Merck has
instituted a separate Patient Assistance Program (the "Crixivan(R) Program,"
together with the General Program, the "Programs") to help provide access to
Crixivan(R), for patients with medical needs who lack prescription coverage and
cannot afford drug treatment;

         WHEREAS, the Foundation desires that Medco dispense, on behalf of the
Foundation, Merck Products belonging to the Foundation, and Merck desires that
Medco dispense Crixivan(R), through one or more of Medco's pharmacies, as
provided herein, by mail in connection with the Programs;

         WHEREAS, Medco and Merck have developed an electronic feed between the
Nominated Agent (defined below) for the General Program and Medco pursuant to
which such Nominated Agent may electronically transmit to Medco eligibility
information with respect to patients under the General Program (the "Eligibility
Electronic Feed"); and

         WHEREAS, also as part of the foregoing, the Parties further desire to
enter into this Agreement to set forth Medco's obligation with respect to the
Programs.

         NOW, THEREFORE, in consideration of the foregoing and the covenants and
agreements set forth below, the Parties agree as follows:

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                                    ARTICLE I

                                   DEFINITIONS

     For the purpose of this Agreement, the following capitalized terms shall
have the following meanings:

     1.1 Ancillary Agreements. "Ancillary Agreements" shall have the meaning set
forth in the Master Separation and Distribution Agreement.

     1.2 Confidential Disclosure Agreement. "Confidential Disclosure Agreement"
shall mean that certain Confidential Disclosure Agreement to be entered into
between Merck and Medco.

     1.3 Dispensing Pharmacies. "Dispensing Pharmacies" shall mean mail order
pharmacies of Medco or its Subsidiaries located in the U.S. from which the Merck
Products shall be dispensed, on behalf of the Foundation, from the Foundation
Stock thereof in accordance with Article II.

     1.4 Effective Date. "Effective Date" shall mean the date hereof.

     1.5 Expiration Date. "Expiration Date" shall have the meaning set forth in
Article 10.

     1.6 Master Separation Agreement. "Master Separation Agreement" shall mean
that certain Master Separation and Distribution Agreement to be entered into
between Merck and Medco.

     1.7 Merck Products. "Merck Products" means pharmaceutical products (not
including Crixivan(R)), other than injectables and vaccines, that (w) are
manufactured by Merck or any of its Subsidiaries, (x) have been approved or
recommended by the U.S. Food and Drug Administration, (y) may be dispensed only
pursuant to a Prescription under applicable law and (z) are subject to an
effective patent granted by the U.S. Patent and Trademark Office.

     1.8 Nominated Agent. "Nominated Agent" shall mean one or more third party
vendors from time to time employed by Merck or the Foundation to administer the
initial application receipt, application review, general program eligibility
determination, and patient enrollment functions of the Programs. The Nominated
Agent for the General Program is currently TeleRx Marketing Inc. The Nominated
Agent for the Crixivan(R) Program is currently the Lash Group. Merck and the
Foundation shall have the right to replace Nominated Agents or appoint
additional Nominated Agents for all or any portion of either of the Programs.
Merck or the Foundation shall provide Medco with reasonable advance notice of
any anticipated appointment of a new Nominated Agent to allow Medco to develop
appropriate operational links with such Nominated Agent to insure continuous
service for the Programs.

     1.9 Foundation Stock. "Foundation Stock" means, with respect to any Merck
Product, at any time, the quantity of such Merck Product previously delivered to
Medco or any of its Subsidiaries by or on behalf of the Foundation for use in
the General Program and not previously dispensed, on behalf of the Foundation,
under the General Program pursuant to

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Article 2 or returned to the Foundation in accordance with Section 4.2 hereof.
Medco agrees that it and its Subsidiaries will accept delivery of any Merck
Products, from time to time, delivered to them, by or on behalf of the
Foundation, solely for the purpose of dispensing such Merck Products to indigent
patients in connection with the General Program.

     1.10 Merck PAP Stock. "Merck PAP Stock" means, at any time, the quantity of
Crixivan(R) previously delivered to Medco or any of its Subsidiaries by or on
behalf of Merck for use in the Crixivan(R) Program and not previously dispensed,
on behalf of Merck, under the Crixivan(R) Program pursuant to Article 2 or
returned to Merck in accordance with Section 4.2 hereof. Medco agrees that it
and its Subsidiaries will accept delivery of Crixivan(R), from time to time,
delivered to them, by or on behalf of Merck, solely for the prupose of
dispensing such Crixivan(R) to indigent patients in connection with the
Crixivan(R) Program.

     1.11 Person. "Person" means any individual, corporation, association,
partnership (general or limited), joint venture, trust, estate, limited
liability company, or other legal entity or organization.

     1.12 Prescription. "Prescription" means a valid and legal order to dispense
a Merck Product or Crixivan(R).

     1.13 Programs. "Programs" shall have the meaning set forth in the Recitals.

     1.14 Subsidiary. "Subsidiary" of any Party means a corporation or other
organization whether incorporated or unincorporated, of which at least a
majority of the securities or interests having by the terms thereof ordinary
voting power to elect at least a majority of the board of directors or others
performing similar functions with respect to such corporation or other
organization is directly or indirectly owned or controlled by such Party or by
any one or more of its Subsidiaries, or by such Party and one or more of its
Subsidiaries. For purposes of this Agreement, neither Medco nor any of its
Subsidiaries shall be deemed to be a Subsidiary of Merck.

     1.15 "Term" shall have the meaning set forth in Section 2.6.

                                   ARTICLE II

                                    SERVICES

     During the Term, Medco shall provide the following services with respect to
the Programs:

     2.1  Patient Enrollment. Receipt of the initial applications with respect
to each of the Programs, and application review, general program eligibility
determination and enrollment functions with respect to each Program, shall be
the responsibility of the applicable Nominated Agent.

     2.2  Prescriptions For the General Program. (a) The Nominated Agent for the
General Program will be responsible for sending to Medco eligibility and
Prescription information with respect to patients eligible to participate in the
General Program. Eligibility

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information with respect to the General Program shall be sent to Medco by the
Nominating Agent through the Eligibility Electronic Feed. On the day that any
eligibility information is sent through the Eligibility Electronic Feed, the
Nominated Agent shall either (1) send the original prescription form via Federal
Express (or other comparable overnight courier providing a traceable, secure
method of shipment) for receipt by Medco at a Dispensing Pharmacy (the address
of which shall be provided to the Nominated Agent by Medco) on the following day
or (2) send a copy of the original prescription form to Medco pursuant to the
Faxable Application Process (as defined in Section 2.5 below). Refill requests
under the General Program may be made by the patient or prescribing physician
using a toll free number established by Medco or by mail (it being understood
that patients and physicians will be discouraged from making refill requests by
mail). When Medco has received all eligibility and Prescription information with
respect to a Prescription or any request for a refill in accordance with the
foregoing, Medco shall cause a Dispensing Pharmacy to dispense, on behalf of the
Foundation, the Merck Product covered by such Prescription (or refill) as
written (subject to the next sentence) from the Foundation Stock thereof, by
mailing such Merck Products via Federal Express (or other comparable courier
providing a traceable, secure method of shipment), two (2) day ground, directly
to the patient or, at the physician's request (as set forth in the applicable
application form), directly to the patient's physician's office. Prescriptions
under the General Program may provide for up to a 90-day supply at a time with
up to three refills each with up to a 90-day supply.

          (b) In addition to providing services with respect to the General
Program as otherwise provided in this Agreement, Medco shall continue to provide
services with respect to the General Program in accordance with the Memorandum
of Understanding between the Merck and Medco, effective April 1, 1996, relating
to the General Program from the date hereof until June 30, 2002; provided that
the fees and reimbursement amounts payable to Medco for providing such services
shall be determined in accordance with Article 3 of this Agreement.

     2.3  Prescriptions for the Crixivan(R) Program. The Nominated Agent for the
Crixivan(R) Program will be responsible for sending to Medco hard-copy paper
eligibility and Prescription information with respect to patients eligible to
participate in the Crixivan(R) Program. Merck and Medco shall cooperate to
maintain a 24-hour turn-around time for this transfer of such information. Such
information shall be sent via any traceable, secure method to a Dispensing
Pharmacy (the address of which shall be provided to the Nominated Agent by
Medco). Refill requests under the Crixivan(R) Program may be made by
transmitting a refill request, including the patients' name and ID (and Social
Security number and Prescription number, if available), to Medco by facsimile
(to a facsimile number specified by Medco. When Medco has received all
eligibility and Prescription information (including the original Prescription
form) with respect to a Prescription or any request for a refill for Crixivan(R)
in accordance with the foregoing, Medco shall cause a Dispensing Pharmacy to
dispense on behalf of Merck, the Crixivan(R) covered by such Prescription (or
refill) as written (subject to the next sentence) from the Merck PAP Stock of
Crixivan(R), by mailing such Crixivan(R) via Federal Express (or other
comparable courier providing a traceable, secure method of shipment), two (2)
day ground, directly to the patient or, at the physician's request (as set forth
in the applicable application form), directly to the patient's physician's
office. Prescriptions under the Crixivan(R)

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Program may provide for up to a 90-day supply at a time with up to three refills
each with up to a 90-day supply.

     2.4   Prescription Volume; Design Changes. (a) Merck or the Foundation
shall use commercially reasonable efforts to provide to Medco monthly good faith
estimates of anticipated Prescription volume under the General Program and the
Crixivan(R) Program for the following six-month period. If any such estimate
provided by Merck or the Foundation anticipates that the compounded volume
growth of the General Program and the Crixivan(R) Program will exceed the
compounded volume growth for such Programs estimated as of the date hereof by
the parties Medco will provide to Merck or the Foundation Medco's good faith
estimate of any capital expenditures Medco will be required to make for the
purpose of providing services hereunder with respect to the Programs. After
Medco's delivery of such estimate to Merck or the Foundation, the parties shall
negotiate in good faith with the goal of agreeing on the specific amount of
capital expenditures Medco will be required to make that is allocable to that
portion of the anticipated compounded volume growth for the General Program and
the Crixivan(R) Program that exceeds the compounded volume growth for such
Programs estimated as of the date hereof by the parties (the "Anticipated Excess
Volume"). Merck or the Foundation agrees to reimburse Medco for the capital
expenditures incurred by Medco in accordance with a budget approved by Merck or
the Foundation setting forth the amounts of capital expenditures allocable to
the Anticipated Excess Volume.

     (b) In the event that at any time during the Term, Merck or the Foundation
proposes to implement material changes to the design of the Programs (other than
increases in volume under the Programs, which shall be subject to Section
2.4(a)), Merck or the Foundation shall provide to Medco a written notice
describing such proposed design changes in reasonable detail. Within 20 days
after its receipt of such notice, Medco will provide to Merck or the Foundation
Medco's good faith estimate of any of the out-of-pocket expenses Medco will be
required to incur to implement the proposed design changes. After Medco delivers
such estimate to Merck or the Foundation, the parties shall negotiate in good
faith with the goal of agreeing on a budget for the out-of-pocket expenses to be
incurred by Medco to implement the proposed design changes (a "Design Change
Budget"). Medco shall implement the proposed design changes in accordance with a
Design Change Budget agreed by the parties as promptly as practicable after the
parties reach agreement thereon. Merck or the Foundation shall reimburse Medco
for the out-of-pocket expenses incurred by Medco in connection with the
implementation of the proposed design changes in accordance with the agreed-upon
Design Change Budget.

     (c) The parties shall designate one or more representatives to communicate
with the designated representatives of the other with respect to the subject
matter of this Section 2.4. The parties shall provide each other with the names
and contact information of their designated representatives.

     2.5   Additional Services. In relation to the General Program (but not the
Crixivan Program), Medco shall:

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     .    provide a data entry function for each Prescription verifying such
          Prescription against eligibility information received from the
          Nominated Agent through the Electronic Feed;

     .    engage in ongoing support interactions with physicians in respect of
          the General Program to ensure that the Foundation Stock subject to the
          General Program can be dispensed;

     .    capture all information on Prescriptions that have been fulfilled on a
          claims file using Medco's standard record layout and electronically
          provide such data to the Nominated Agent according to Medco's standard
          bi-weekly billing cycle;

     .    in the period between Medco receiving each electronic eligibility file
          and Prescription from the Nominated Agent and Medco supplying the
          Nominated Agent with a claims file tape, maintain a status inquiry
          support capability (or receive transferred calls from patients
          directly from the Nominated Agent to check actual prescription
          dispensing status) so that the Nominated Agent can access information
          with respect to any application;

     .    maintain an automated Prescription refill service allowing patients
          and prescribing physicians to order permissible refills using a toll
          free number established for that purpose (the "Automated Refill
          Service"). The Automated Refill Service shall provide for a refill
          process agreed upon by the parties; provided that such process shall
          employ the use of all applicable technologies available to Medco (to
          the extent technologically feasible), and Medco shall use commercially
          reasonable efforts to ensure that such process maximizes time
          efficiencies and savings for the Foundation; and

     .    develop and incorporate technology to enable Medco to support a
          process for receipt by facsimile from the Nominated Agent of
          Prescription information (the "Faxable Application Process"), as
          promptly as practicable (but in any event within 90 days) of the
          Nominated Agent and Medco reaching agreement with respect to the
          detailed design and technical architecture for the Faxable Application
          Process. Medco shall use commercially reasonable efforts to reach such
          agreement with the Nominated Agent as promptly as practicable after
          the date of this Agreement.

     2.6  Term. This Agreement shall remain in effect from the Effective Date
through the Expiration Date (the "Term"). The "Expiration Date" shall be
December 31, 2006; provided that in the event of the early termination of this
Agreement in accordance with Article V, the date of such early termination shall
be "Expiration Date".

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                                  ARTICLE III

                                  COMPENSATION

     3.1 Charges. For the services provided by Medco to Merck or the Foundation
hereunder, Merck or the Foundation shall pay Medco the fees, and reimburse Medco
for its expenses, as set forth on Schedule 3.1.

     3.2 Payment Terms. Merck or the Foundation shall pay and reimburse Medco in
accordance with Section 3.1 for the services provided hereunder during each
fiscal month of Medco during the Term, within thirty (30) days after a receipt
of an invoice therefor (accompanied by such documentation verifying the charges
reflected thereon as shall be reasonably requested by Merck or the Foundation).

                                   ARTICLE IV

                               GENERAL PROVISIONS

     4.1 Parameters. Medco shall, and shall cause to be provided, the services
under this Agreement in the manner in which such services were provided prior to
the date of this Agreement (or in a manner that is more technologically
advanced, or efficient).

     4.2 Foundation Stock and Merck PAP Stock. The Parties agree and acknowledge
that Merck Products included in the Foundation Stock and Crixivan(R) included in
the Merck PAP Stock are being delivered to Medco or its Subsidiaries solely for
the purpose of dispensing such Merck Products and Crixivan(R) to indigent
patients, on behalf of Merck or the Foundation, under the Programs in accordance
with Article II hereof, and such Merck Products and Crixivan(R), shall remain
solely the property of the Foundation or Merck, respectively, until dispensed
under the applicable Program in accordance with Article II hereof. Medco and its
Subsidiaries shall exercise the same care and diligence in holding and
safeguarding the Merck Products included in the Foundation Stock and Crixivan(R)
included in Merck PAP Stock that they exercise in holding and safeguarding
pharmaceutical products owned by them. If this Agreement is terminated for any
reason, Medco shall promptly complete the dispensing of all Foundation Stock and
Merck PAP Stock to indigent patients in accordance with the Programs or, if such
dispensing is impossible or Merck or the Foundation makes a specific request
that such dispensing not be carried out, promptly upon request by Merck or the
Foundation, respectively, return such Foundation Stock to the Foundation or
Merck PAP Stock to Merck at an address to be supplied by the Foundation or
Merck, as the case may be.

     4.3 Good Faith Cooperation; Consents. The Parties will use good faith
efforts to cooperate with each other in all matters relating to the provision
and receipt of the services to be provided hereunder. Such cooperation shall
include exchanging information, and obtaining all third party consents,
authorizations, licenses, sublicenses or approvals necessary to permit each
Party to perform its obligations hereunder (including by way of example, not by
way of limitation, rights to use third party software needed for the performance
of services hereunder). Each Party will maintain, in accordance with its
standard document retention procedures, documentation supporting the information
relevant to cost calculations and cooperate with each

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other in making such information available as needed in the event of a tax or
regulatory audit, whether in the United States or any other country.

     4.4 Promotional Materials. Merck or the Foundation shall have sole
responsibility for preparing and distributing all promotional materials relating
to the Programs, and the cost of preparing and distributing such materials shall
be borne by Merck or the Foundation. No Medco Party may prepare or distribute
any promotional materials relating to any Program without consent of Merck or
the Foundation. Merck or the Foundation shall provide Medco with an opportunity
to review and comment on promotional materials with respect to the Programs to
be disseminated by Merck or the Foundation prior to the public dissemination
thereof. Merck or the Foundation shall use commercially reasonable efforts to
provide a draft of any such promotional materials to Medco at lease 30 days
prior to the public dissemination thereof.

     4.5 Medco Participation. The Parties acknowledge Medco has not participated
in, and shall not participate in the design of the Programs relative to
financial criteria, patient selection, etc. Medco has assisted in the design of
dispensing technology and automated process design to administer the Patient
Assistance Program.

     4.6 Information. Any information or data generated by any Medco Party in
connection with its services hereunder ("Program Information") shall be the
property of Merck or the Foundation and shall not be disclosed or shared by any
Medco Party with any Person except as permitted by Merck or the Foundation,
provided that information concerning the dispensing of prescription drugs
customarily maintained by Medco shall be maintained by Medco and may be
disclosed by Medco to regulatory agencies having jurisdiction or as otherwise
required under applicable laws or regulations. Medco shall disclose Program
Information to third-parties to the extent requested by Merck or the Foundation.
No Medco Party shall use Program Information for purposes other than patient
care in connection with the Programs.

                                    ARTICLE V

                                EARLY TERMINATION

     5.1 Early Termination. Merck or the Foundation may terminate this Agreement
any time upon sixty- (60) days prior written notice to Medco. Any party may
terminate this Agreement if the another breaches in any material respect any of
its obligations hereunder and does not cure such breach hereunder within thirty
(30) days after being notified of such breach.

     5.2 Survival. Those Sections of this Agreement that, by their nature, are
intended to survive termination will survive in accordance with their terms.

                                   ARTICLE VI

                                 CONFIDENTIALITY

     Without limiting the obligations of the Parties under this Agreement, the
terms of the Confidential Disclosure Agreement shall apply to any Confidential
Information (as defined in that Agreement) of either Merck and Medco provided to
the other for the purpose of providing

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services under this Agreement. For purposes of the preceding sentence,
information provided by the Foundation shall be deemed information provided by
Merck.

                                   ARTICLE VII

                                 PATIENT PRIVACY

     7.1 Medco Obligations. Medco represents and warrants and agrees that it
will perform all of its duties under this Agreement in compliance with all
applicable federal, state, local and foreign laws and regulations and licensing
requirements, including but not limited to those related to patient
notification, authorization and consent, privacy of medical records and medical
information. By way of example, Medco is required under the Standards adopted
pursuant to the Health Insurance Portability and Accountability Act of 1996,
either directly as a covered entity or in its role as a business associate of
its health plan clients, to assure that protected health information (all as
defined in such Standards) is used or disclosed only in accordance with such
Standards. If at any time during the Term, Medco concludes that it cannot
perform one or more obligations under this Agreement because of legal or
regulatory restrictions imposed upon it, Medco shall promptly notify Merck or
the Foundation, explain why it believes it cannot legally perform the
obligation, and provide Merck or the Foundation with an estimate of the impact
of the restriction on its performance of this Agreement as a whole. Nothing in
this Agreement is intended to allow Medco to create by contract an impediment to
performance of this Agreement that differs from any restriction to which Medco
is subject as to either drug manufacturers generally or any broader category of
third parties.

     7.2 Obligations of Merck and the Foundation. Merck and the Foundation
represent, warrant and agree that the data provided by Merck and the Foundation
to Medco pursuant to this Agreement shall not violate the privacy and/or
security rights of any third party or individual and that such data shall be
provided by Merck and the Foundation in compliance with the applicable rules and
regulations governing the use of data, including but not limited to, rules and
regulations governing the use of patient medical information. Merck and the
Foundation further represent, warrant and agree that prior to providing any such
data to Medco they will have obtained any and all necessary consents or
authorizations required for Merck or the Foundation to provide the data to
Medco.

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                                  ARTICLE VIII

                        RELATIONSHIP BETWEEN THE PARTIES

                                   ARTICLE IX

The relationship between the Parties established under this Agreement is that of
independent contractors and no Party is an employee, agent, partner, or joint
venturer of or with any other.

                                   ARTICLE X

                               DISPUTE RESOLUTION

     ANY DISPUTE, CONTROVERSY OR CLAIM BETWEEN THE PARTIES HERETO ARISING OUT OF
OR RELATING TO THIS AGREEMENT, INCLUDING, WITHOUT LIMITATION, DISPUTES
CONCERNING THE VALIDITY, INTERPRETATION OR PERFORMANCE OF OR UNDER THIS
AGREEMENT OR ANY TERM OR PROVISION HEREOF, SHALL BE EXCLUSIVELY GOVERNED BY AND
SETTLED IN ACCORDANCE WITH THE PROVISIONS OF ARTICLE III OF THE INDEMNIFICATION
AGREEMENT.

                                   ARTICLE XI

                                  MISCELLANEOUS

     11.1 Press Releases. Merck or the Foundation shall use commercially
reasonable efforts to provide Medco with notice of, and an opportunity to
review, any press release relating to any of the Programs prior to the release
thereof. Medco shall not make any public statement with respect to any of the
Programs without the prior approval of Merck or the Foundation.

     11.2 Entire Agreement. This Agreement, the Separation Agreement and the
other Ancillary Agreements and the Exhibits, Annexes and Schedules referenced or
attached hereto and thereto constitute the entire agreement between the Parties
with respect to the subject matter hereof and thereof and shall supersede all
prior written and oral and all contemporaneous oral agreements and
understandings with respect to the subject matter hereof and thereof.

     11.3 Governing Law; Forum. This Agreement shall be construed in accordance
with, and all Disputes hereunder shall be governed by, the procedural (except to
the extent inconsistent with the procedures set forth in Article III of the
Indemnification Agreement) and substantive laws of the State of New York as to
all matters regardless of the laws that might otherwise govern under principles
of conflicts of laws applicable thereto. Under no circumstances may any party
seek or be awarded punitive damages under this Agreement. Any state court
sitting in New York county, New York and/or the United States District Court for
the Southern District of New York shall have exclusive jurisdiction and venue,
and each party hereto hereby submits to such jurisdiction and venue and
irrevocably waives, to the fullest extent permitted by applicable law, any
objection it may now or hereafter have to such jurisdiction or the laying of
such venue over any Disputes between the parties that are permitted to be
brought in a court, or the enforcement

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of any decision of an arbitrator, pursuant to Article III of the Indemnification
Agreement. Each of the parties hereby irrevocably waives any right to a jury
trial with respect to a Dispute.

     11.4 Notices. Except as expressly provided herein, all notices and other
communications required or permitted to be given by any Party pursuant to the
terms of this Agreement shall be in writing to and shall be deemed to have been
duly given when delivered in person, by express or overnight mail delivery by a
nationally recognized courier (delivery charges prepaid), or by registered or
certified mail (postage prepaid, return receipt requested), as follows:

          if to Merck:

                                       Merck & Co., Inc.
                                       351 North Sumneytown Pike
                                       North Wales, PA 19454-2505
                                       Attention: Senior Director, Economic
                                       Affairs

          with a copy to:

                                       Merck & Co., Inc.
                                       One Merck Drive
                                       P.O. Box 100
                                       Whitehouse Station, New Jersey 08889
                                       Attention: General Counsel

          if to the Foundation:

                                       Merck Patient Assistance
                                       Program, Inc.
                                       c/o Merck & Co., Inc.
                                       One Merck Drive
                                       P.O. Box 100
                                       Whitehouse Station, New Jersey 08889
                                       Attention: Tax Department

          if to Medco:

                                       Medco Health Solutions, Inc.
                                       100 Parsons Pond Road
                                       Franklin Lakes, New Jersey 07417
                                       Attention: General Counsel

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or to such other address as the Party to whom notice is given may have
previously furnished to the other in writing in the manner set forth above. All
notices and other communication shall be deemed to have been given and received
on the date of actual delivery.

     11.5 Binding Effect; Assignment; Third-Party Beneficiaries. Medco may not,
directly or indirectly, in whole or in part, whether by operation of law or
otherwise, assign or transfer this Agreement or its rights or obligations
hereunder, without prior written consent of Merck or the Foundation and, except
as otherwise permitted hereby, any attempted assignment, transfer or delegation
without such prior written consent shall be voidable at the sole option of Merck
or the Foundation. Merck may not, without Medco's prior written consent, assign
or transfer this Agreement other than to an Affiliate or in connection with a
merger, consolidation, sale or transfer of all or substantially all of its
assets or substantially all of its pharmaceutical business or any similar
business combination transaction. The Foundation may not assign or transfer this
Agreement or its rights or obligations hereunder without the prior written
consent of Medco other than to an Affiliate of the Foundation or of Merck or in
connection with a merger, consolidation, sale or transfer of all or
substantially all of Merck's assets or substantially all of Merck's
pharmaceutical business or any similar business combination transaction of
Merck. Without limiting the foregoing, this Agreement shall be binding upon
Merck and the other members of the Merck Group, the Foundation, and Medco and
the other members of the Medco Group and their respective legal representatives,
successors and permitted assigns, and nothing in this Agreement, express or
implied, is intended to confer upon any other Person any rights or remedies of
any nature whatsoever under or by reason of this Agreement.

     11.6 Offset. In addition to, and not in limitation of, any other remedies
any member of the Merck Group, the Foundation, or any Merck Indemnitee (as
defined in the Indemnification Agreement) may be entitled to under the
Separation Agreement, any Ancillary Agreement (including this Agreement) or any
Intercompany Agreement (as defined in the Indemnification Agreement) , any
member of the Merck Group, the Foundation, or any Merck Indemnitee may satisfy
any amounts owed to such member of the Merck Group, the Foundation, or Merck
Indemnitee by any member of the Medco Group by means of an offset against any
amounts any member of the Merck Group or the Foundation may from time to time
owe to any member of the Medco Group or an Medco Indemnitee, whether under the
Separation Agreement, any Ancillary Agreement (including this Agreement), any
Intercompany Agreement, any other agreement or arrangement existing between any
member of the Merck Group and any member of the Medco Group, or otherwise.

     11.7 Severability. If any term or other provision of this Agreement or any
Annexes, Schedules or Exhibits attached hereto is determined by a court,
administrative agency or arbitrator to be invalid, illegal or incapable of being
enforced by any rule of law or public policy, all other conditions and
provisions of this Agreement will nevertheless remain in full force and effect
so long as the economic or legal substance of the transactions contemplated
hereby is not affected in any manner materially adverse to any Party. Upon such
determination that any term or other provision is invalid, illegal or incapable
of being enforced, the Parties shall negotiate in good faith to modify this
Agreement so as to effect the original intent of the parties hereto as closely
as possible in an acceptable manner to the end that transactions contemplated
hereby are fulfilled to the fullest extent possible. If the Parties are unable
to reach an agreement on any

                                       12

<PAGE>

such modification, the arbitrator selected in accordance with Article III of the
Indemnification Agreement shall have the authority to determine such
modification.

     11.8  Failure or Indulgence Not Waiver. No failure or delay on the part of
any Party in the exercise of any right hereunder shall impair such right or be
construed to be a waiver of, or acquiescence in, any breach of any
representation, warranty or agreement herein, nor shall any single or partial
exercise of any such right preclude other or further exercise thereof or of any
other right.

     11.9  Amendment. No change or amendment will be made to this Agreement
except by an instrument in writing signed on behalf of each of the Parties.

     11.10 Interpretation. The headings contained in this Agreement, in any
Annex, Exhibit or Schedule hereto and in the table or contents to this Agreement
are for reference purposes only and shall not affect in any way the meaning or
interpretation of this Agreement. Any capitalized term used in any Annex,
Schedule or Exhibit but not otherwise defined therein, shall have the meaning
assigned to such term in this Agreement. When a reference is made in this
Agreement to an Article or Section, or an Annex, Exhibit or Schedule, such
reference shall be to an Article or Section of, or an Annex, Exhibit or Schedule
to, this Agreement unless otherwise indicated.

     11.11 Counterparts. This Agreement, including any Annexes, Schedules and
Exhibits hereto, and the other documents referred to herein, may be executed in
counterparts, each of which shall be deemed to be an original but all of which
shall constitute one and the same agreement.

     11.12 Memoranda of Understandings. Merck, the Foundation, and Medco agree
and acknowledge that, subject to Section 2.2(b) this Agreement, shall supercede
and replace in its entirety the Memoranda of Understandings between Merck and
Medco regarding the Programs.

     11.13 Indemnification Agreement. The indemnification obligation of Merck
and Medco with respect to this Agreement shall be as set forth in the
Indemnification Agreement. The indemnification obligations of the Foundation and
Medco shall be identical the those of Merck and Medco under the Indemnification
Agreement.

                                       13

<PAGE>

     IN WITNESS WHEREOF, each of the Parties has caused this Agreement to be
executed in duplicate originals by its duly authorized representatives.

                                MERCK & CO., INC.

                                By: /s/ David W. Anstice
                                   ---------------------------
                                Name:  David W. Anstice
                                Title: President
                                       USHH - The Americas

                                MEDCO HEALTH SOLUTIONS, INC.

                                By: /s/ Robert J. Blyskal
                                   ---------------------------
                                Name:  Robert J. Blyskal
                                Title: Executive Vice President
                                       Operations and Technology

                                MERCK PATIENT ASSISTANCE PROGRAM, INC.

                                By: /s/ Robert C. Shepherd
                                   ---------------------------
                                Name:  Robert C. Shepherd
                                Title: Executive Vice President

                                       14<PAGE>

                                                                    EXHIBIT 10.9

                           E-HEALTH SERVICES AGREEMENT

                                     BETWEEN

                                MERCK & CO., INC.

                                       AND

                          MEDCO HEALTH SOLUTIONS, INC.

<PAGE>

                           E-HEALTH SERVICES AGREEMENT

     THIS E-HEALTH SERVICES AGREEMENT (this "Agreement"), dated as of June 28,
2002, is entered into between Merck & Co., Inc., a New Jersey corporation
("Merck"), and Medco Health Solutions, Inc., a Delaware corporation ("Medco").
Merck and Medco are each referred to individually as a "Party," and collectively
as the "Parties".

                                    RECITALS

     A.  Medco has developed and currently operates through its web site at
www.merckmedco.com certain Internet based, interactive web pages that provide
targeted health information to Medco and non-Medco members in four eHealth
Centers including Cardiovascular (Hypertension, High Cholesterol), Arthritis,
Women's Health (Osteoporosis) and Wellness (Vaccines) (the "eHealth Centers").

     B.  Through the eHealth Centers, Medco also tracks patient usage and
behavior, based in part on patient self-reporting, and provides to Merck
periodic reports containing aggregated information concerning patient
utilization and behavior modification.

     C.  The Parties desire to continue to exchange information under the terms
and conditions of this Agreement. Accordingly, the Parties agree as follows:

                                    ARTICLE I

                                   DEFINITIONS

     For the purpose of this Agreement, the following capitalized terms shall
have the following meanings:

     1.1 Confidential Disclosure Agreement. "Confidential Disclosure Agreement"
shall mean the Confidential Disclosure Agreement to be entered into between the
Parties.

     1.2 Current eHealth Centers. "Current eHealth Centers" shall have the
meaning set forth in Section 2.1.

     1.3 Effective Date. "Effective Date" shall mean the date that this
Agreement is executed by the Parties.

     1.4 eHealth Centers. "eHealth Centers" shall have the meaning set forth in
Recital A and shall include "Current eHealth Centers".

     1.5 eHealth Data Services. "eHealth Data Services" shall mean the data
services provided by Medco to Merck in connection with the eHealth Centers as
set forth in Article II.

     1.6 Indemnification Agreement. "Indemnification Agreement" shall mean that
certain Indemnification and Insurance Matters Agreement to be entered into
between the Parties.

                                       -1-

<PAGE>

     1.7  Intellectual Property. "Intellectual Property" shall mean (a) all
inventions (whether patentable or unpatentable and whether or not reduced to
practice), all improvements thereon, and all patents, patent applications and
patent disclosures, together with all reissuances, continuations,
continuations-in-part, revisions, extensions and reexaminations thereof, (b) all
trademarks, service marks, trade dress, logos, trade names, domain names, and
corporate names, together with all translations, adaptations, derivations and
combinations thereof and including all goodwill associated therewith, and all
applications, registrations and renewals in connection therewith, (c) all
copyrights and all applications, registrations and renewals in connection
therewith, (d) all trade secrets and confidential business information
(including ideas, research and development, know-how, formulas, compositions,
manufacturing and production processes and techniques, methods, schematics,
technology, technical data, designs, drawings, flowcharts, block diagrams,
specifications, customer and supplier lists, pricing and cost information and
business and marketing plans and proposals), (e) all computer software
(including data and related documentation), (f) all other proprietary rights,
(g) all copies and tangible embodiments of the foregoing categories of
intellectual property listed in subsections (a) through (f) (in whatever form or
medium), and (h) all licenses, sublicenses, agreements, or permissions related
to the foregoing categories of intellectual property listed in subsections (a)
through (g).

     1.8  Person. "Person" means any individual, corporation, association,
partnership (general or limited), joint venture, trust, estate, limited
liability company, or other legal entity or organization.

     1.9  Registered Members. "Registered Members" shall mean individuals who
have registered on merckmedco.com and are members of a Medco health plan.

     1.10 Registered Non-Members. "Registered Non-Members" shall mean
individuals who have registered on merckmedco.com but are not members of a Medco
health plan.

     1.11 Subsidiary. "Subsidiary" of either Party means a corporation or other
organization whether incorporated or unincorporated, of which at least a
majority of the securities or interests having by the terms thereof ordinary
voting power to elect at least a majority of the board of directors or others
performing similar functions with respect to such corporation or other
organization is directly or indirectly owned or controlled by such Party or by
any one or more of its Subsidiaries, or by such Party and one or more of its
Subsidiaries. For purposes of this Agreement, neither Medco nor any of its
Subsidiaries shall be deemed to be a Subsidiary of Merck.

     1.12 Term. The "Term" of this Agreement is set forth in Section 5.1.

     1.13 Termination Date. "Termination Date" shall mean the date that the
Agreement is terminated pursuant to Article V.

                                       -2-

<PAGE>

                                   ARTICLE II

                        DATA AND SERVICES TO BE PROVIDED

     2.1  Provision of eHealth Centers. Among the eHealth Centers that Medco
currently operates are a Women's Health (Osteoporosis) Center; an Arthritis
Center; a Cardiovascular Center (Hypertension and High Cholesterol); and a
Wellness (Vaccines) Center. During the Term of this Agreement, Medco shall
continue the operation of the Women's Health (Osteoporosis), Arthritis,
Cardiovascular (Hypertension and High Cholesterol), and Wellness (Vaccines)
eHealth Centers (the "Current eHealth Centers"), and ensure that each such
eHealth Center provides, at minimum, the functions set forth in Schedule 2.1.

     2.2  New eHealth Centers. In the event that (a) Medco develops additional
eHealth Centers, Merck shall have the right of first refusal to invest in such a
center. The scope and terms of any such a project will be determined by Medco at
its sole discretion. Medco may make Merck aware of any such intentions to
develop a center at any point in time (through written communication); Merck
will respond to Medco in writing regarding an interest in investing within 30
calendar days or it will be assumed that no current interest exists and Medco's
obligations under Section 2.2 have been completed.

     2.3  eHealth Data Services. Medco shall provide to Merck the reports listed
in Schedule 2.3 concerning the success of the eHealth Centers in attracting
Registered Members and influencing their behavior.

     2.4  Medco Control Group Data. Medco shall, where feasible, report on the
impact of the eHealth Centers using well-matched statistically significant
control groups to compare the behavior of patients who use the eHealth Centers
against the behavior of similar patients who did not use the eHealth Centers.

     2.5  Clarifying and Backup Data. Upon reasonable request by Merck, Medco
shall provide clarifications to and backup data for the reports and statistics
specified in Schedule 2.3, subject to Medco's duty to safeguard patient
information under Article IX of this Agreement.

     2.6  Merck Input Regarding Content and Data Collection. Merck shall have
the right, at least once in each calendar quarter, to contribute approved
non-promotional educational materials (patient or physician focused) for
consideration for inclusion in the eHealth Centers. The inclusion or use in the
eHealth Centers of the material provided by Merck shall be at the discretion of
Medco. Merck shall have the right, within reason, to request additional types of
information be gathered from eHealth users and analyses be performed on data
collected from or on eHealth Center users. Medco shall use its best efforts to
accommodate Merck's suggestions regarding these additional data and analyses,
assuming they are not prohibited by law, regulation, or third-party contractual
limitation, and that they are not operationally or methodologically
impracticable. In the event that Medco declines to follow such suggestions,
Medco shall provide Merck with a good faith reason for its decision.

     2.7  Control Over Content. Medco shall have final control over the content
of the eHealth Centers and all other health information presented on
merckmedco.com.

                                       -3-

<PAGE>

                                   ARTICLE III

                                  COMPENSATION

     3.1  Fees for Services. During the Term of this Agreement, Merck shall pay
Medco fees as shown in Schedule 3.1.A, payable in equal installments on a
quarterly basis in advance.

     3.2  Invoices. Medco shall provide Merck with a quarterly invoice
reflecting the fees payable for the upcoming quarter.

                                   ARTICLE IV

                               GENERAL OBLIGATIONS

     4.1  Performance Parameters. To the extent that performance parameters or
specifications are established in this Agreement, Medco shall perform its
obligations in accordance with those parameters and specifications. To the
extent that specific performance parameters are not specifically enumerated in
this Agreement, Medco shall use reasonable commercial efforts to provide the
eHealth Data Services in the same manner, and with at least the same level of
diligence, as Medco has used in the provision of similar services to Merck in
the 12 months prior to the Effective Date.

                                    ARTICLE V

                              TERM AND TERMINATION

     5.1  Term. The Term of this Agreement shall commence on the Effective Date
and continue through and including December 31, 2004 except that with respect to
the Wellness (Vaccines) eHealth Center, the Term of this Agreement shall end on
December 31, 2002, and Merck shall have an annual right to renew, at its sole
option (exercised by November 1 of each year), this Agreement for additional one
year periods for the years 2003, 2004 and 2005.

     5.2  Termination. Merck may terminate this Agreement for any reason or no
reason, effective January 1, 2003 or at any later date, upon at least 90 days
prior written notice to Medco. Effective January 1, 2003 or at any later date,
Merck may also terminate this Agreement in part, by eliminating its request for
eHealth Data Services with respect to one or more of the eHealth Centers, for
any reason or no reason, upon at least 90 days prior written notice to Medco. In
the event that Merck terminates this Agreement in part as to one or more of the
Women's Health (Osteoporosis) Center, the Arthritis Center or the Cardiovascular
Center (Hypertension and High Cholesterol), the fees payable under Schedule
3.1.A.1 shall be reduced by one third per year for each eHealth Center for which
services are terminated, and also reduced pro rata for the number of months left
in the year if the services are terminated mid-year. In the event that Merck
terminates this Agreement mid-year as to the Wellness (Vaccines) eHealth Center,
the fees payable under Schedule 3.1.A.2 shall be reduced pro rata for the number
of months left in the year.

                                       -4-

<PAGE>

     5.3  Effect of Termination. Termination of this Agreement shall relieve and
release the Parties from any further liabilities and obligations hereunder with
respect to the services terminated except any liabilities or obligations that
accrued prior to the effective date of such termination and except as provided
in Section 5.4.

     5.4  Survival. Articles VI, VIII and XI shall survive termination of this
Agreement.

                                   ARTICLE VI

                                 CONFIDENTIALITY

     6.1  The terms of the Confidential Disclosure Agreement shall apply to any
Confidential Information (as defined in Section 1.2 of that agreement) of either
Party provided to the other Party for the purpose of providing Services under
this Agreement.

                                   ARTICLE VII

                        RELATIONSHIP BETWEEN THE PARTIES

     7.1  The relationship between the Parties established under this Agreement
is that of independent contractors and neither Party is an employee, agent,
partner, or joint venturer of or with the other.

                                  ARTICLE VIII

                              INTELLECTUAL PROPERTY

     8.1  Merck shall retain all right, title and interest in the materials and
methodologies that it provides to Medco for use in, on, or in connection with
the eHealth Centers. However, Merck grants to Medco a perpetual, non-exclusive
and non-royalty-bearing license to use those suggestions, materials and
methodologies in the design and content of the eHealth Centers, subject to
Section 6.1 of this Agreement.

     8.2  Medco shall retain all right, title and interest in the compilation of
data and reports to be provided to Merck under this Agreement, and in the data,
analyses, and methodologies used to produce Data Services. However, Medco grants
to Merck a perpetual, non-exclusive and non-royalty bearing license to use those
data, reports, and analyses, subject to Section 6.1 of this Agreement.

     8.3  The Parties have the right to publish, either individually or jointly
with one another, the compilation of data and analyses to be provided to Merck
under this Agreement. If either Party intends to publish those data and
analyses, it shall give prior notice to the other Party of its intent to do so,
explaining how, when and where it intends to publish the information, and the
intended target audience. In the event of such publication, neither Party shall
have a duty to account to the other Party for the financial proceeds (if any)
resulting from the publication.

                                       -5-

<PAGE>

     8.4  As between the Parties, Medco shall retain all right, title and
interest in the content of the eHealth Centers, except to the extent that such
content is provided to Medco by Merck.

                                   ARTICLE IX

                                 PATIENT PRIVACY

     9.1  Medco represents and warrants that it will perform all of its duties
under this Agreement in compliance with all applicable federal, state, local and
foreign laws and regulations and licensing requirements, including but not
limited to those related to patient notification, authorization and consent,
privacy of medical records and medical information. By way of example, Medco is
required under the Standards adopted pursuant to the Health Insurance
Portability and Accountability Act of 1996, either directly as a covered entity
or in its role as a business associate of its health plan clients, to assure
that protected health information (all as defined in such Standards) is used or
disclosed only in accordance with such Standards.

     9.2  Medco may collect and/or generate information that identifies or could
be used to identify an individual, including names, addresses, medical histories
and test results ("individually identifiable information") directly from
patients, consumers, prospective clinical trial subjects, and other individuals.
Medco agrees to handle individually identifiable information in compliance with
applicable law.

                                    ARTICLE X

                         REPRESENTATIONS AND WARRANTIES

     10.1 Intellectual Property. Medco represents and warrants that it has the
right to operate the eHealth Centers and provide the eHealth Data Services, and
that operation of the eHealth Centers and provision of the eHealth Data Services
shall not infringe the Intellectual Property rights of any third party.

                                   ARTICLE XI

                                 INDEMNIFICATION

     11.1 Indemnification. Medco shall indemnify and hold harmless the Merck
Indemnitees (as defined in the Indemnification Agreement) in respect of all
Liabilities (as defined in the Indemnification Agreement) related to, arising
from, asserted against or associated with Medco's providing services hereunder.
Such indemnification obligation shall be a Medco Liability for purposes of the
Indemnification Agreement, and the provisions of Article I thereof with respect
to indemnification shall govern with respect thereto. Merck shall indemnify and
hold harmless the Medco Indemnitees (as defined in the Indemnification
Agreement) in respect of all Liabilities (as defined in the Indemnification
Agreement) related to or arising from Merck's provision of content under Section
2.6 of this Agreement. Such indemnification obligation shall be a Merck
Liability for purposes of the Indemnification Agreement, and the provisions of
Article I thereof with respect to indemnification shall govern with respect
thereto.

                                       -6-

<PAGE>

     11.2  Additional Indemnification. In addition to, and not in limitation of,
the indemnification provided under Section 11.1, Medco shall indemnify and hold
harmless the Merck Indemnitees from and against any and all loss, damage or
expense, including reasonable attorneys' fees, that Merck may sustain or incur
as a result of any claim, suit or proceeding arising out of or in connection
with: (1) any actual or alleged negligent or willful act or omission of Medco,
or any of its employees, agents or subcontractors; (2) any actual or alleged
violation by Medco, or any of its employees, agents or subcontractors of any
law, statute, ordinance or regulation; (3) any failure to obtain necessary
consents, authorizations, approvals or releases for use of the data and/or
provision of the services hereunder and any violation or alleged violation of
any third party or individual's privacy right by the data and/or services
provided to Merck under this Agreement; (4) any infringement or alleged
infringement by the eHealth Centers and/or eHealth Data Services provided to
Merck under this Agreement upon any Intellectual Property rights of any third
party; or (5) any failure to perform any obligation under this Agreement. Such
indemnification obligation shall be a Medco Liability for purposes of the
Indemnification Agreement, and the provisions of Article I thereof with respect
to indemnification shall govern with respect thereto.

                                   ARTICLE XII

                               DISPUTE RESOLUTION

     12.1  Any dispute, controversy or claim arising between the Parties
relating to the validity, interpretation or performance of this Agreement shall
be resolved in accordance with the provisions of Article III of the
Indemnification Agreement.

     12.2  Injunctive Relief. Notwithstanding the provisions of Section 12.1,
Medco acknowledges that any violation of Article(s) II, VI and/or VIII of this
Agreement will cause Merck immediate and irreparable harm that monetary damages
cannot adequately remedy. The parties agree that, upon any actual or impending
violation of Article(s) II, VI and/or VIII of this Agreement, in addition to any
money damages or other legal remedy that Merck may have, Merck shall also be
entitled to equitable relief, including injunctive relief and specific
performance (and Medco shall not plead in defense thereto that there would be an
adequate remedy at law), without bond or proof of damages. Such equitable relief
may be sought in an arbitration proceeding pursuant to Section 3.1(c) of the
Indemnification Agreement (without first complying with the negotiation
provisions of Section 3.1(a) thereof) or in a court, subject to Section 14.2 of
this Agreement. In the event of litigation relating to this Agreement, if a
court of competent jurisdiction determines that Medco has breached Article(s)
II, VI and/or VIII of this Agreement, Medco shall be liable and pay to Merck the
reasonable legal fees and costs incurred in connection with such litigation,
including any appeal from such litigation.

     12.3  Limitation on Damages. In the event of a breach of this Agreement,
the damages (if any) payable by either Party shall not exceed the total annual
payments due under the Agreement for its entire Term as set forth in Schedule
3.1.A.

                                       -7-

<PAGE>

                                  ARTICLE XIII

                                  FORCE MAJEURE

     13.1  Neither Party shall be deemed to have breached this Agreement or to
have failed or delayed in the performance of all or any portion of its
obligations under this Agreement if such Party is prevented from doing so by a
cause or causes beyond its control, provided that such Party is using reasonable
commercial efforts to remedy its non-performance or to arrange for appropriate
alternative methods of performance. Without limiting the generality of the
foregoing, such causes include acts of God or the public enemy, fires, floods,
storms, earthquakes, locusts, tornadoes ("twisters"), mudslides, riots,
terrorism, strikes, lock-outs, wars and war-operations, restraints of government
power or communication line failure or other circumstances beyond such Party's
control, or by reason of the judgment, ruling or order of any court or agency of
competent jurisdiction or change of law or regulation subsequent to the
execution of this Agreement. If either Party is affected by a force majeure
event, such party shall, within 10 days of its occurrence, give notice to the
other Party stating the nature of the event, its anticipated duration and any
action being taken to avoid or minimize its effect. The suspension of
performance shall be of no greater scope and no longer duration than is required
and the non-performing Party shall use its best efforts to remedy its inability
to perform.

     13.2  If either Party's performance under this Agreement is suspended
pursuant to Section 13.1, the other Party's obligations (except for those
covered by Articles VI, VIII and XI) shall be suspended for the same period of
time. If Medco is unable substantially to perform its obligations under this
Agreement for more than 5 business days by reason of an act covered by Section
13.1, the fees payable by Merck shall be reduced pro rata for each additional
calendar day that Medco's non-performance continues. If Medco's suspension of
services continues for more than 30 days, Merck shall have the right to
terminate this Agreement on 7 days notice.

                                   ARTICLE XIV

                                  MISCELLANEOUS

     14.1  Entire Agreement. This Agreement, the Schedules, and any other
agreements specifically referred to in this Agreement constitute the entire
agreement between the Parties with respect to the subject matter of this
Agreement and shall supersede all prior or contemporaneous written or oral
agreements or understandings with respect to the same subject matter.

     14.2  Governing Law; Forum. This Agreement shall be construed in accordance
with, and all Disputes hereunder shall be governed by, the procedural (except to
the extent inconsistent with the procedures set forth in Article III of the
Indemnification Agreement) and substantive laws of the State of New York as to
all matters regardless of the laws that might otherwise govern under principles
of conflicts of laws applicable thereto. Under no circumstances may any party
seek or be awarded punitive damages under this Agreement. Any state court
sitting in New York county, New York and/or the United States District Court for
the Southern District of New York shall have exclusive jurisdiction and venue,
and each party hereto hereby submits to such

                                       -8-

<PAGE>

jurisdiction and venue and irrevocably waives, to the fullest extent permitted
by applicable law, any objection it may now or hereafter have to such
jurisdiction or the laying of such venue over any Disputes between the parties
that are permitted to be brought in a court, or the enforcement of any decision
of an arbitrator, pursuant to Article III of the Indemnification Agreement. Each
of the parties hereby irrevocably waives any right to a jury trial with respect
to a Dispute.

     14.3  Descriptive Headings. The headings contained in this Agreement,
including its Schedules and table of contents, are for reference purposes only
and shall not affect in any way the meaning or interpretation of this Agreement.
Any capitalized term used in any Schedule but not otherwise defined therein,
shall have the meaning assigned to such term in this Agreement. When a reference
is made in this Agreement to an Article or a Section, such reference shall be to
an Article or Section of this Agreement unless otherwise indicated.

     14.4  Notices. All notices and other communications required or permitted
to be given by either Party pursuant to the terms of this Agreement shall be in
writing to and shall be deemed to have been duly given when delivered in person,
by express or overnight mail delivery by a nationally recognized courier
(delivery charges prepaid), or by registered or certified mail (postage prepaid,
return receipt requested), as follows:

           if to Merck:

                                Merck & Co., Inc.
                                Sumneytown Pike
                                P.O. Box 4
                                West Point, PA 19486
                                Attention: Christopher Haney,
                                Senior Director, PBM National Accounts

           with a copy to:
                                Merck & Co., Inc.
                                One Merck Drive
                                P.O. Box 100
                                Whitehouse Station, New Jersey 08889
                                Attention: General Counsel

           if to Medco:

                                Medco Health Solutions, Inc.
                                100 Parsons Pond Road
                                Franklin Lakes, New Jersey 07417
                                Attention: General Counsel

or to such other address as the Party to whom notice is given may have
previously furnished to the other in writing in the manner set forth above. All
notices and other communication shall be deemed to have been given and received
on the date of actual delivery.

                                       -9-

<PAGE>

     14.5  Nonassignability; Third-Party Beneficiaries. Medco may not, directly
or indirectly, in whole or in part, whether by operation of law or otherwise,
assign or transfer this Agreement or its rights or obligations hereunder,
without Merck's prior written consent and, except as otherwise permitted hereby,
any attempted assignment, transfer or delegation without such prior written
consent shall be voidable at the sole option of Merck. Merck may not, without
Medco's prior written consent, assign or transfer this Agreement other than to
an Affiliate or in connection with a merger, consolidation, sale or transfer of
all or substantially all of its pharmaceutical business or assets or any similar
business combination transaction. Without limiting the foregoing, this Agreement
shall be binding upon Merck and the other members of the Merck Group (as defined
in the Separation Agreement (as defined in the Indemnification Agreement)) and
Medco and the other members of the Medco Group (as defined in the Separation
Agreement) and their respective legal representatives, successors and permitted
assigns, and nothing in this Agreement, express or implied, is intended to
confer upon any other Person any rights or remedies of any nature whatsoever
under or by reason of this Agreement.

     14.6  Offset. In addition to, and not in limitation of, any other remedies
any member of the Merck Group or any Merck Indemnitee (as defined in the
Indemnification Agreement) may be entitled to under the Separation Agreement,
any Ancillary Agreement (as defined in the Separation Agreement) (including this
Agreement) or any Intercompany Agreement (as defined in the Indemnification
Agreement), any member of the Merck Group or any Merck Indemnitee may satisfy
any amounts owed to such member of the Merck Group or Merck Indemnitee by any
member of the Medco Group by means of an offset against any amounts any member
of the Merck Group may from time to time owe to any member of the Medco Group or
an Medco Indemnitee, whether under the Separation Agreement, any Ancillary
Agreement (including this Agreement), any Intercompany Agreement, any other
agreement or arrangement existing between any member of the Merck Group and any
member of the Medco Group, or otherwise.

     14.7  Severability. If any term or other provision of this Agreement is
determined by a court, administrative agency or arbitrator, by any court or in
any binding arbitration, to be invalid, illegal or incapable of being enforced
by any rule of law or public policy, all other conditions and provisions of this
Agreement will nevertheless remain in full force and effect so long as the
economic or legal substance of the transactions contemplated hereby is not
affected in any manner materially adverse to any Party. Upon such determination
that any term or other provision is invalid, illegal or incapable of being
enforced, the Parties shall negotiate in good faith to modify this Agreement so
as to effect the original intent of the Parties as closely as possible in an
acceptable manner to the end that transactions contemplated hereby are fulfilled
to the fullest extent possible. If the Parties are unable to reach an agreement
on any such modification, the arbitrator selected in accordance with Article III
of the Indemnification Agreement shall have the authority to determine such
modification.

     14.8  Failure or Indulgence not Waiver; Remedies Cumulative. No failure or
delay on the part of either Party hereto in the exercise of any right hereunder
shall impair such right or be construed to be a waiver of, or acquiescence in,
any breach of any representation, warranty or agreement herein, nor shall any
single or partial exercise of any such right preclude the further exercise
thereof or of any other right. All rights and remedies existing under this
Agreement are cumulative to, and not exclusive of, any rights or remedies
otherwise available.

                                      -10-

<PAGE>

     14.9  Amendment. No change or amendment will be made to this Agreement
except by an instrument in writing signed on behalf of each of the Parties
hereto.

     14.10 Counterparts. This Agreement may be executed in counterparts, which,
taken together, shall be considered to be one and the same instrument.

     IN WITNESS WHEREOF, each of the Parties has caused this Agreement to be
executed in duplicate originals by its duly authorized representatives.

MERCK & CO., INC.                        MEDCO HEALTH SOLUTIONS, INC.

By: /s/ David W. Anstice                 By: /s/ Robert J. Blyskal
    -----------------------------            --------------------------
Name:  David W. Anstice                  Name:  Robert J. Blyskal
Title: President                         Title: Executive Vice President
       USHH - The Americas                      Operations and Technology

                                      -11-

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