McKESSON CORPORATION
DIRECTOR INDEPENDENCE STANDARDS
AS ADOPTED BY THE BOARD
ON JANUARY 21, 2009

A Director will not be considered independent if:

  1. The director is, or has been within the last three years, an employee of the Company, or an immediate family member is, or has been within the last three years, an executive officer, of the Company.

  2. The director has received, or has an immediate family member who has received, during any twelve-month period within the last three years, more than $120,000 in direct compensation from the Company, other than director and committee fees and pension or other forms of deferred compensation for prior service (provided such compensation is not contingent in any way on continued service).

  3. (A) The director is a current partner or employee of a firm that is the Company's internal or external auditor; (B) the director has an immediate family member who is a current partner of such a firm; (C) the director has an immediate family member who is a current employee of such a firm and personally works on the Company's audit; or (D) the director or an immediate family member was within the last three years a partner or employee of such a firm and personally worked on the Company's audit within that time.

  4. The director or an immediate family member is, or has been within the last three years, employed as an executive officer of another company where any of the Company's present executive officers at the same time serves or served on that company's compensation committee.

  5. The director is an executive officer or an employee, or whose immediate family member is an executive officer, of another company (A) which in any of the last three years accounted for at least 2% of the Company's consolidated gross revenues, or (B) for which in any such year the Company accounted for at least 2% or $1 million, whichever is greater, of such other company's consolidated gross revenues.

  6. The director is, or has been within the last three years, an executive officer of another company that is indebted to the Company, or to which the Company is indebted, and the total amount of either company's indebtedness to the other is more than 2% of the respective company's total assets measured as of the last completed fiscal year.

  7. The director serves, or served within the last three years, as an executive officer, director or trustee of a charitable organization, and the Company's discretionary charitable contributions in any single fiscal year exceeded the greater of $1 million or 2% of that organization's total annual charitable receipts. (The Company's matching of employee charitable contributions will not be included in the amount of the Company's contributions for this purpose.)

  8. For relationships not covered by the guidelines above, or for relationships that are covered, but as to which the Board believes a director may nonetheless be independent, the determination of independence shall be made by the directors who satisfy the NYSE independence rules and the guidelines set forth above. However, any determination of independence for a director who does not meet these standards must be specifically explained in the Company's proxy statement.