X0303 4 2010-05-18 0000927653 MCKESSON CORP MCK 0001197897 OWEN MARC E ONE POST STREET SAN FRANCISCO CA 94104 0 1 0 0 EVP, Corp.Strategy & Bus. Dev. Common Stock 2010-05-18 4 M 0 5000 39.81 A 9114.0475 D Common Stock 2010-05-18 4 M 0 40000 45.02 A 49114.0475 D Common Stock 2010-05-18 4 S 0 45000 70.00 D 4114.0475 D Common Stock 1410.6575 I By Profit-Sharing Investment Plan Employee Stock Option (Right-to-buy) 39.81 2010-05-18 4 M 0 5000 0 D 2011-10-25 Common Stock 5000 0 D Employee Stock Option (Right-to-buy) 45.02 2010-05-18 4 M 0 40000 0 D 2012-07-27 Common Stock 40000 0 D Includes 4,114.0475 shares purchased under the issuer's ESPP. Option exercise and sale pursuant to a previously adopted plan dated 03/13/2009, intended to comply with Rule 10b5-1(c). This option was granted on 10/26/2001 and vest as follows: 50% on 10/26/2003 and 50% on 1/27/2004. This option was granted on 7/27/2005 and vests 100% on 3/31/2006. Donna Spinola, Attorney-in-fact 2010-05-19