EXHIBIT 10.20

                              McKESSON HBOC, INC.

                              STOCK PURCHASE PLAN

              (As amended and restated through January 27, 1999)



     1. Establishment. There is hereby adopted the McKesson HBOC, Inc. Stock
Purchase Plan (hereinafter called the "Plan")(formerly known as the McKesson
Corporation Stock Purchase Plan), subject to approval by holders of at least a
majority of the outstanding shares of voting stock of the Corporation.

     2. Stock Subject to the Plan. Rights may be granted under the Plan from
time to time to key employees of the Corporation and its Subsidiaries to
purchase from the Corporation an aggregate of not more than 2,500,000 shares of
Common Stock ($.01 par value) of the Corporation.

     3. Administration of the Plan. The Plan shall be administered by a
committee (the "Committee") consisting of not less than two directors of the
Company to be appointed by the Board, each of whom is a "non-employee director"
within the meaning of Rule 16b-3 under the Securities Exchange Act of 1934. No
member of the Committee shall be eligible to receive benefits under the Plan.
The Committee may from time to time determine which eligible employees shall be
granted rights under the Plan, and the number of shares for which a right shall
be granted to an employee. The Committee shall have the sole authority, in its
absolute discretion, to adopt, amend, and rescind such rules and regulations as,
in its opinion, may be advisable in the administration of the Plan, to construe
and interpret the Plan, the rules and regulations, and to make all other
determinations deemed necessary or advisable for the administration of the Plan.
All decisions, determinations and interpretations of the Committee shall be
final and binding on all grantees and purchasers of stock under the Plan and on
other interested parties.

     4. Eligibility. Persons eligible for rights under the Plan are those key
employees of the Corporation or its Subsidiaries designated from time to time by
the Committee. Members of the Board of Directors of the Corporation who are not
employed as regular salaried officers or employees of the Corporation or of any
Subsidiary of the Corporation may not participate in the Plan.

     5. Exercise Price. The exercise price of the stock covered by each right
shall not be less than the fair market value of such stock on the date the right
is exercised, which shall be the closing sale price on such day on the New York
Stock Exchange.

     6. Right Terms and Conditions; Extension of Credit by the Corporation. The
term of each right shall be for such period not in excess of thirty days as the
Committee may determine. Purchases shall be evidenced by a written Stock
Purchase Agreement which may provide for the payment of the purchase price
(i) by a payment in cash or (ii) entirely by a


promissory note payable on such repayment schedule as the Committee may
determine or (iii) by any combination of (i) and (ii). The Stock Purchase
Agreement may contain such other terms, provisions, and conditions as are
determined by the Committee. Stock purchased by an employee under the Plan shall
be pledged to the Corporation as collateral for the purchase loan terms and
conditions set forth in the Stock Purchase Agreement.

     7. Voting, Dividend Rights, etc. Shares purchased by employees under the
Plan shall be fully paid and non-assessable and be entitled to voting, dividend
and other rights.

     8. Amendment, Suspension or Termination of the Plan. The Board of Directors
may at any time suspend or terminate this Plan, and may amend it from time to
time in such respects as it may deem advisable.

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