McKesson 2005 Annual Report Download - page 337

Exhibit 24
POWER OF ATTORNEY
KNOW ALL MEN BY THESE PRESENTS THAT the undersigned directors and officers of McKesson Corporation, a Delaware
corporation (the “Company”), do hereby constitute and appoint Ivan D. Meyerson and Kristina Veaco his or her true and lawful attorney and
agent, each with full power and authority (acting alone and without the other) to execute in the name and on behalf of the undersigned as such
Director and/or Officer, under the Securities Act of 1934, as amended, an Annual Report on Form 10-K for the fiscal year ended March 31,
2005, and thereafter to execute and file any and all amendments to such Form, whether filed prior or subsequent to the time such Form
becomes effective. The undersigned hereby grants unto such attorneys and agents, and each of them, full power of substitution or resubstitution
and revocation in the premises and hereby ratifies and confirms all that such attorneys and agents may do or cause to be done by virtue of these
presents.
Dated: April 28, 2005
Wayne A. Budd David M. Lawrence
Wayne A Budd, Esq., Director David. M. Lawrence, M.D., Director
Jeffrey C. Campbell Robert W. Matschulla
t
Jeffrey C. Campbell, Senior Vice President
and Chief Financial Officer
(Principal Financial Officer)
Robert W. Matschullat, Director
John H. Hammergren James V. Napier
John H. Hammergren, Chairman of the Board,
President and Chief Executive Officer
(Principal Executive Officer)
James V. Napier, Director
Alton F. Irby III Nigel A. Rees
Alton F. Irby III, Director Nigel A. Rees, Vice President and Controller
(Principal Accounting Officer)
M. Christine Jacobs Jane E. Shaw
M. Christine Jacobs, Director Jane E. Shaw, Director
Marie L. Knowles Richard Syron
Marie L. Knowles, Director Richard F. Syron, Director