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Exhibit 10.1   MERCK & CO., INC. PLAN FOR DEFERRED PAYMENT OF DIRECTORS COMPENSATION (Amended and Restated April 2, 2004)




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TABLE OF CONTENTS PageArticle I
    
    Purpose
    
    
    1Article II
    
    Election of Deferral, Measurement Methods and Distribution Schedule
    
    
    1Article III
    
    Valuation of Deferred Amounts
    
    
    2Article IV
    
    Redesignation Within a Deferral Account
    
    
    3Article V
    
    Payment of Deferred Amounts
    
    
    4Article VI
    
    Designation of Beneficiary
    
    
    5Article VII
    
    Plan Amendment or Termination
    
    
    6Schedule A
    
    Measurement Methods
    
    
    7
 (i)




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MERCK & CO., INC.
PLAN FOR DEFERRED PAYMENT OF
DIRECTORS COMPENSATION  I.
    
    PURPOSETo provide an arrangement under which directors of Merck & Co., Inc.
other than current employees may (i) elect to voluntarily defer payment
of the annual retainer and meeting and committee fees until after
termination of their service as a director, and (ii) value compensation
mandatorily deferred on their behalf.II.
    
    ELECTION OF DEFERRAL, MEASUREMENT METHODS AND
DISTRIBUTION SCHEDULE  A.
    
    Election of Voluntary Deferral Amount1.
    
    Prior to December 28 of each year, each director is entitled
to make an irrevocable election to defer until termination of
service as a director receipt of payment of (a) 50% or 100% of the
retainer for the 12 months beginning April 1 of the next calendar
year, (b) 50% or 100% of the Committee Chairperson retainer
beginning April 1 of the next calendar year, and (c) 50% or 100% of
the meeting and committee fees for the 12 months beginning April 1
of the next calendar year.2.
    
    Prior to commencement of duties as a director, a director
newly elected or appointed to the Board during a calendar year must
make the election under this paragraph for the portion of the
Voluntary Deferral Amount applicable to such directors first year
of service (or part thereof).3.
    
    The Voluntary Deferral Amount shall be credited as follows:
(1) Meeting and committee fees that are deferred are credited as of
the day the directors services are rendered; (2) if the Board
retainer and/or Committee Chairperson retainer is deferred, a
pro-rata share of the deferred retainer is credited on the last
business day of each calendar quarter. The dates the Voluntary
Deferral Amount, or parts thereof, are credited to the directors
deferred account are hereinafter referred to as the Voluntary
Deferral Dates.B.
    
    Mandatory Deferral Amount1.
    
    On the Friday following the Companys Annual Meeting of
Stockholders (such Friday hereinafter referred to as the Mandatory
Deferral Date), each director will be credited with an amount
equivalent to one-third of the annual cash retainer for the 12 month
period beginning on the April 1 preceding the Annual Meeting (the
Mandatory Deferral Amount). The Mandatory Deferral Amount will be
measured by the Merck Common Stock account.2.
    
    A director newly elected or appointed to the Board after the
Mandatory Deferral Date will be credited with a pro rata portion of
the Mandatory Deferral Amount applicable to such directors first
year of service (or part thereof). Such pro rata portion shall be
credited to the directors account on the first day of such
directors service.




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C.
    
    Election of Measurement MethodEach such annual election referred to in Section A shall include
an election as to the measurement method or methods by which the
value of amounts deferred will be measured in accordance with
Article III, below. The available measurement methods are set
forth on Schedule A hereto.D.
    
    Election of Distribution ScheduleEach annual election referred to in Section A above shall also
include an election to receive payment following termination of
service as a director of all Voluntary Deferral Amounts and
Mandatory Deferral Amounts in a lump sum either immediately or one
year after such termination, or in quarterly or annual
installments over five, ten or fifteen years.  III.
    
    VALUATION OF DEFERRED AMOUNTS  A.
    
    Common Stock1.
    
    Initial Crediting. The annual Mandatory Deferral Amount
shall be used to determine the number of full and partial shares of
Merck Common Stock which such amount would purchase at the closing
price of the Common Stock on the New York Stock Exchange on the
Mandatory Deferral Date.That portion of the Voluntary Deferral Amount allocated to Merck
Common Stock shall be used to determine the number of full and
partial shares of Merck Common Stock which such amount would
purchase at the closing price of the Common Stock on the New York
Stock Exchange on the applicable Voluntary Deferral Date.However, should it be determined by the Committee on Corporate
Governance of the Board of Directors that a measurement of Merck
Common Stock on any Mandatory or Voluntary Deferral Date would not
constitute fair market value, then the Committee shall decide on
which date fair market value shall be determined using the
valuation method set forth in this Article III, Section A.1.At no time during the deferral period will any shares of Merck
Common Stock be purchased or earmarked for such deferred amounts
nor will any rights of a shareholder exist with respect to such
amounts.2.
    
    Dividends.Each directors account will be credited with the
additional number of full and partial shares of Merck Common Stock
which would have been purchasable with the dividends on shares
previously credited to the account at the closing price of the
Common Stock on the New York Stock Exchange on the date each
dividend was paid.3.
    
    Distributions.Distribution from the Merck Common Stock
account will be valued at the closing price of Merck Common Stock on
the New York Stock Exchange on the distribution date. 2




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B.
    
    Mutual Funds1.
    
    Initial Crediting.The amount allocated to each Mutual Fund
shall be used to determine the full and partial Mutual Fund shares
which such amount would purchase at the closing net asset value of
the Mutual Fund shares on the Mandatory or Voluntary Deferral Date,
whichever is applicable. The directors account will be credited
with the number of full and partial Mutual Fund shares so
determined.At no time during the deferral period will any Mutual Fund shares
be purchased or earmarked for such deferred amounts nor will any
rights of a shareholder exist with respect to such amounts.2.
    
    Dividends.Each directors account will be credited with the
additional number of full and partial Mutual Fund shares which would
have been purchasable, at the closing net asset value of the Mutual
Fund shares as of the date each dividend is paid on the Mutual Fund shares, with the dividends which would have been paid on the number
of shares previously credited to such account (including pro rata
dividends on any partial shares).3.
    
    Distributions.Mutual Fund distributions will be valued
based on the closing net asset value of the Mutual Fund shares on
the distribution date.C.
    
    AdjustmentsIn the event of a reorganization, recapitalization, stock split,
stock dividend, combination of shares, merger, consolidation,
rights offering or any other change in the corporate structure or shares of the Company or a Mutual Fund, the number and kind of shares or units of such investment measurement method available
under this Plan and credited to each directors account shall be
adjusted accordingly.  IV.
    
    REDESIGNATION WITHIN A DEFERRAL ACCOUNT  A.
    
    GeneralA director may request a change in the measurement methods used to
value all or a portion of his/her account other than Merck Common
Stock. Amounts deferred using the Merck Common Stock method and
any earnings attributable to such deferrals may not be
redesignated.The change will be effective on (i) the day when
the redesignation request is received pursuant to administrative
guidelines established by the Human Resources Financial Services
area of the Treasury department, provided the request is received
prior to the close of the New York Stock Exchange on such day or
(ii) the next following business day if the request is received
when the New York Stock Exchange is closed. 3




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B.
    
    When Redesignation May Occur1.
    
    During Active Service. There is no limit on the number of
times a director may redesignate the portion of his/her deferred
account permitted to be redesignated. Each such request shall be
irrevocable and can be designated in whole percentages or as a
dollar amount.2.
    
    After Death. Following the death of a director, the legal
representative or beneficiary of such director may redesignate
subject to the same rules as for active directors set forth in
Article IV, Section B.1.C.
    
    Valuation of Amounts to be RedesignatedThe portion of the directors account to be
redesignated will be valued at its cash
equivalent and such cash equivalent will be converted into shares
or units of the other measurement method(s). For purposes of such
redesignations, the cash equivalent of the value of the Mutual
Fund shares shall be the closing net asset value of such Mutual
Fund on (i) the day when the redesignation request is received
pursuant to administrative guidelines established by the Human
Resources Financial Services area of the Treasury department,
provided the request is received prior to the close of the New
York Stock Exchange on such day or (ii) the next following
business day if the request is received when the New York Stock
Exchange is closed.  V.
    
    PAYMENT OF DEFERRED AMOUNTS  A.
    
    PaymentAll payments to directors of amounts deferred will be in cash in
accordance with the distribution schedule elected by the director
pursuant to Article II, Section D. Distributions shall be pro
rata by measurement method. Distributions shall be valued on the
fifteenth day of the distribution month (or, if such day is not a
business day, the next business day) and paid as soon thereafter
as possible.B.
    
    Changes to Distribution Schedule Prior to TerminationUpon the request of a director made at any time during the
calendar year immediately preceding the calendar year in which
service as a director is expected to terminate, the Committee on
Corporate Governance of the Board of Directors (the Committee),
in its sole discretion, may authorize: (a) an extension of a
payment period beyond that originally elected by the director not
to exceed that otherwise allowable under Article II, Section D,
and/or (b) a payment frequency different from that originally
elected by the director. Such request may not be made with regard
to amounts deferred after December 31, 1990 using the Merck Common
Stock method and to any earnings attributable to such deferrals.
Deferrals into Merck Common Stock made after December 31, 1990 and
any earnings thereon may only be distributed in accordance with
the schedule elected by the director under Article II, Section D
or determined by the Committee on Corporate Governance under
Article VI. 4




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C.
    
    Post-Termination Changes to Distribution ScheduleFollowing termination of service as a director, each director may
make one request for a further extension of the period for
distribution of his/her deferred compensation. Such request must
be received by the Committee on Corporate Governance prior to the
first distribution to the participant under his/her previously
elected distribution schedule. Any revised distribution schedule
may not exceed the deferral period otherwise allowable under
Article II, Section C. This request may be granted and a new
payment schedule determined in the sole discretion of the
Committee on Corporate Governance.Such request may not be made with regard to amounts deferred after
December 31, 1990 using the Merck Common Stock Method and to any
earnings attributable to such deferrals. Any retired director who
is not subject to U.S. income tax may petition the Committee on
Corporate Governance to change payment frequency, including a lump
sum distribution, and the Committee on Corporate Governance may
grant such petition if, in its discretion, it considers there to
be reasonable justification therefor. Deferrals into Merck Common
Stock made after December 30, 1990 and any earnings thereon may
only be distributed in accordance with the schedule elected by the
director under Article II, Section D or determined by the
Committee on Corporate Governance under Article VI.D.
    
    ForfeituresA directors deferred amount attributable to the Mandatory
Deferral Amount and earnings thereon shall be forfeited upon his
or her removal as a director or upon a determination by the
Committee on Corporate Governance in its sole discretion, that a
director has:  (i)
    
    joined the Board of, managed, operated,
participated in a material way in, entered employment with,
performed consulting (or any other) services for, or
otherwise been connected in any material manner with a
company, corporation, enterprise, firm, limited partnership,
partnership, person, sole proprietorship or any other
business entity determined by the Committee on Corporate
Governance in its sole discretion to be competitive with the
business of the Company, its subsidiaries or its affiliates
(a Competitor);(ii)
    
    directly or indirectly acquired an equity
interest of five (5) percent or greater in a Competitor; or(iii)
    
    disclosed any material trade secrets or other
material confidential information, including customer lists,
relating to the Company or to the business of the Company to
others, including a Competitor.  VI.
    
    DESIGNATION OF BENEFICIARYIn the event of the death of a director, the deferred amount at the date
of death shall be paid to the last named beneficiary or beneficiaries
designated by the director, or, if no beneficiary has been designated, to
the directors legal representative, in one or more 5




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installments as the Committee on Corporate Governance in its sole
discretion may determine.VII.
    
    PLAN AMENDMENT OR TERMINATIONThe Committee on Corporate Governance shall have the right to amend or
terminate this Plan at any time for any reason. 6




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SCHEDULE A MEASUREMENT METHODS (January 1, 2002  January 10, 2003) Merck Common Stock Mutual Funds American Century Emerging Markets FundAmerican Century Europacific Growth FundFidelity Destiny IFidelity Dividend GrowthFidelity Equity Income FundFidelity Low-Priced Stock FundFidelity Retirement Money MarketFidelity Spartan Government IncomeFidelity Spartan U.S. Equity IndexFranklin Small-Mid Cap Growth AJanus EnterpriseJanus Growth & IncomeLiberty Acorn ZPIMCO Foreign Bond InstitutionalPIMCO Long Term US Government InstitutionalPIMCO Total Return InstitutionalPutnam Global Equity Fund A*Putnam International Voyager APutnam Vista AT. Rowe Price Blue Chip Growth FundVanguard Asset Allocation
 *From September 20, 2002  September 30, 2002, this investment was
briefly named the Putnam Global Growth Fund A as a result of the merger,
in September 2002, of Putnam Global Equity Fund A with Putnam Global
Growth Fund A. The merged fund briefly retained the name Putnam Global
Growth Fund A. Effective October 1, 2002, the merged fund changed its
name to Putnam Global Equity Fund A. 7




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SCHEDULE A MEASUREMENT METHODS (Effective January 11, 2003 to July 31, 2003) Merck Common Stock Mutual Funds American Century Emerging Markets InstitutionalAmerican Funds EuroPacific Growth FundFidelity Destiny IFidelity Dividend GrowthFidelity Equity-IncomeFidelity Low-Priced StockFidelity Retirement Money MarketFidelity Spartan Government IncomeFidelity Spartan U.S. Equity IndexFranklin Small-Mid Cap Growth AJanus EnterpriseJanus Growth & IncomeLiberty Acorn Class ZPIMCO Foreign Bond InstitutionalPIMCO Long Term US Government InstitutionalPIMCO Total Return InstitutionalPutnam Global Equity APutnam International Capital Opportunities Fund A*Putnam Vista AT. Rowe Price Blue Chip GrowthVanguard Asset Allocation
 * Prior to April 30, 2003, known as Putnam International Voyager Fund A. Redesignation of Deferred Amounts measured by Putnam Vista A on July 31, 2003 Prior to 4 p.m. ET on July 31, 2003, each participant who has any part of
his/her account measured by the Putnam Vista A measurement method may
redesignate the amount in such measurement method in accordance with Article
IV. If a participant does not redesignate the amount measured by the Putnam
Vista A measurement method to any other remaining measurement method before 4
p.m. ET on July 31, 2003, then the amount in the Putnam Vista A account shall
be redesignated as of 4 p.m. ET on July 31, 2003, to the Fidelity Mid-Cap Stock
Fund. 8




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SCHEDULE A MEASUREMENT METHODS (Effective July 31, 2003  November 19, 2003) Merck Common Stock Mutual Funds American Century Emerging Markets InstitutionalAmerican Funds EuroPacific Growth FundColumbia Acorn Class Z*Fidelity Destiny IFidelity Dividend GrowthFidelity Equity-IncomeFidelity Low-Priced StockFidelity Mid-Cap Stock FundFidelity Retirement Money MarketFidelity Spartan Government IncomeFidelity Spartan U.S. Equity IndexFranklin Small-Mid Cap Growth AJanus EnterpriseJanus Growth & IncomePIMCO Foreign Bond InstitutionalPIMCO Long Term US Government InstitutionalPIMCO Total Return InstitutionalPutnam Global Equity APutnam International Capital Opportunities Fund A**T. Rowe Price Blue Chip GrowthVanguard Asset Allocation
 * Prior to October 2003, known as Liberty Acorn Class Z ** Prior to April 30, 2003, known as Putnam International Voyager Fund A Redesignation of Deferred Amounts measured by Putnam Global Equity A and Putnam
International Capital Opportunities Fund A (collectively, the Putnam Funds)
on November 19, 2003 Prior to 4 p.m. ET on November 19, 2003, each participant who has any part of
his/her Deferred Compensation Account measured by a Putnam Funds investment
alternative may redesignate the amount in such investment alternative in
accordance with Article IV. If a participant does not redesignate the amount
measured by a Putnam Funds investment alternative to any other remaining
investment alternative(s) before 4 p.m. ET on November 19, 2003, then the
amount in the Putnam Funds investment alternative shall be redesignated as of 4
p.m. ET on November 19, 2003, to the Fidelity Retirement Money Market
Portfolio. 9




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SCHEDULE A MEASUREMENT METHODS
(November 19, 2003 to April 2, 2004) Merck Common Stock Mutual Funds American Century Emerging Markets InstitutionalAmerican Funds EuroPacific Growth FundColumbia Acorn Class Z*Fidelity Destiny IFidelity Dividend GrowthFidelity Equity-IncomeFidelity Low-Priced StockFidelity Mid-Cap Stock FundFidelity Retirement Money MarketFidelity Spartan Government IncomeFidelity Spartan U.S. Equity IndexFranklin Small-Mid Cap Growth AJanus EnterpriseJanus Growth & IncomePIMCO Foreign Bond InstitutionalPIMCO Long Term US Government InstitutionalPIMCO Total Return InstitutionalT. Rowe Price Blue Chip GrowthVanguard Asset Allocation
 *   Prior to October 2003, known as Liberty Acorn Class Z. 10




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SCHEDULE A MEASUREMENT METHODS
(April 2, 2004) Merck Common Stock Mutual Funds American Century Emerging Markets InstitutionalAmerican Funds EuroPacific Growth FundColumbia Acorn Class Z*Fidelity Destiny IFidelity Dividend GrowthFidelity Equity-IncomeFidelity Low-Priced StockFidelity Mid-Cap Stock FundFidelity Retirement Money MarketFidelity Spartan Government IncomeFidelity Spartan U.S. Equity IndexJanus EnterpriseJanus Growth & IncomePIMCO Foreign Bond InstitutionalPIMCO Long Term US Government InstitutionalPIMCO Total Return InstitutionalT. Rowe Price Blue Chip GrowthVanguard Asset Allocation
 *   Prior to October 2003, known as Liberty Acorn Class Z. 11