EXHIBIT 1 June 30, 1999 Ms. Heidi Yodowitz Senior Vice President and Controller and Acting Chief Financial Officer McKesson HBOC, Inc. One Post Street San Francisco CA 94104 Dear Ms. Yodowitz, This is to confirm that, because McKesson HBOC, Inc. (the "Company") has not yet finalized its consolidated financial statements as of and for the three years ended March 31, 1999, Deloitte & Touche LLP was unable to complete the audits of the Company's consolidated financial statements for such periods by June 29, 1999. Yours truly, /s/ Deloitte & Touche LLP