Statement of Changes in Beneficial Ownership (4)

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * HAMMERGREN JOHN H	2. Issuer Name and Ticker or Trading Symbol MCKESSON CORP [ MCK ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __ X __ Director                      _____ 10% Owner __ X __ Officer (give title below)      _____ Other (specify below) Chairman, President & CEO
(Last)          (First)          (Middle) ONE POST STREET	3. Date of Earliest Transaction (MM/DD/YYYY) 4/25/2016
(Street) SAN FRANCISCO, CA 94104 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _ X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	4/25/2016		M		101833   (1)	A	$40.46	101833	D
Common Stock	4/25/2016		S		101833   (1)	D	$176.8149	0	D
Common Stock								590256.925   (2)	I	By Trust
Common Stock								4140.103	I	By Profit-Sharing Investment Plan

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (Right-to-buy)	$40.46	4/25/2016		M			101833   (1)	(3)	5/26/2016	Common Stock	101833	$0	101833	D

Explanation of Responses:
( 1)	Option exercise and sale pursuant to a previously adopted plan, intended to comply with Rule 10b5-1(c).
( 2)	Represents 489,785.925 shares held under the Hammergren Family Trust; 12,554 held in the JHH 2010 GRAT #8; 12,554 shares in the JHH 2010 GRAT #9; 12,554 held in the JHH 2010 GRAT #10; 12,555 held in the JHH 2010 GRAT #11; 12,563 in the WLH 2010 GRAT #8; 12,563 in the WLH 2010 GRAT #9; 12,564 in the WLH 2010 GRAT #10; 12,564 in the WLH 2010 GRAT #11.
( 3)	This option granted 05/26/2009 vested 25% per year, commencing on the 1st anniversary of the grant date.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
HAMMERGREN JOHN H ONE POST STREET SAN FRANCISCO, CA 94104	X		Chairman, President & CEO

Signatures
Donna Spinola, Attorney-in-fact		4/26/2016
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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