Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 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 ^*

Tyler Brian Scott

2. Date of Event Requiring Statement (MM/DD/YYYY) 8/2/2018

3. Issuer Name and Ticker or Trading Symbol

MCKESSON CORP [MCK]

(Last) (First) (Middle)

ONE POST STREET

4. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director _____ 10% Owner
___ X ___ Officer (give title below) _____ Other (specify below)
President & COO /

(Street)

SAN FRANCISCO, CA 94104

(City) (State) (Zip)

5. 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 Beneficially Owned
1.Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	12192	D
Common Stock	205.8778	I	By McKesson Corporation 401(k) Retirement Savings Plan

*Table II - Derivative Securities Beneficially Owned ( e.g.* , puts, calls, warrants, options, convertible securities)**
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivate Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)
Employee Stock Option (right-to-buy)	⁽¹⁾	10/31/2019	Common Stock	6000	$93.31	D
Employee Stock Option (right-to-buy)	⁽²⁾	5/21/2020	Common Stock	16250	$118.41	D
Employee Stock Option (right-to-put)	⁽³⁾	5/27/2021	Common Stock	22042	$183.37	D
Employee Stock Option (right-to-buy)	⁽⁴⁾	8/5/2021	Common Stock	1467	$191.81	D
Employee Stock Option (right-to-buy)	⁽⁵⁾	5/26/2022	Common Stock	21752	$237.86	D
Employee Stock Option (right-to-buy)	⁽⁶⁾	5/24/2023	Common Stock	37083	$182.77	D
Employee Stock Option (right-to-buy)	⁽⁷⁾	5/23/2024	Common Stock	34713	$159.00	D
Employee Stock Option (right-to-buy)	⁽⁸⁾	5/30/2025	Common Stock	25296	$144.43	D
Restricted Stock Units (RSUs)	⁽⁹⁾	⁽⁹⁾	Common Stock	8152	$0	D
Restricted Stock Units (RSUs)	⁽¹⁰⁾	⁽¹⁰⁾	Common Stock	20772	$0	D

Explanation of Responses:
(1)	This option vests 25% on 10/31/2013, 25% on 10/31/2014, 25% on 10/31/2015 and 25% on 10/31/2016.
(2)	This option vests 25% on 5/21/2014, 25% on 5/21/2015, 25% on 5/21/2016, and 25% on 5/21/2017.
(3)	This option vests 25% on 5/27/2015, 25% on 5/27/2016, 25% on 5/27/2017 and 25% on 5/27/2018.
(4)	This option vests 25% on 8/5/2015, 25% on 8/5/2016, 25% on 8/5/2017 and 25% on 8/5/2018.
(5)	This option vests 25% on 5/26/2016, 25% on 5/26/2017, 25% on 5/26/2018 and 25% on 5/26/2019.
(6)	This option vests 25% on 5/24/2017, 25% on 5/24/2018, 25% on 5/24/2019 and 25% on 5/24/2020.
(7)	This option vests 25% on 5/23/2018, 25% on 5/23/2019, 25% on 5/23/2020 and 25% on 5/23/2021.
(8)	This option vests 25% on 5/30/2019, 25% on 5/30/2020, 25% on 5/30/2021 and 25% 5/30/2022.
(9)	These RSUs vest 100% on 5/30/2021.
(10)	These RSUs vest 33% on 5/30/2019, 33% on 5/30/2020 and 33% on 5/30/2021.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Tyler Brian Scott ONE POST STREET SAN FRANCISCO, CA 94104			President & COO

Signatures
Donna Spinola, Attorney-in-fact		8/3/2018
^** 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 5(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.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.