SYY DEF 14A Report ended Nov. 18, 2022

There are 11 director nominees for election to the Board. The directors elected at the Annual Meeting will hold office until the 2025 Annual Meeting of Shareholders and until their successors have been elected and qualified, or until their earlier resignation, removal or death. Linda P. Mantia, who is no longer an independent director, and Susan R. Salka, who has served on the Board for almost ten years, will not be standing for re-election. Both of their terms will end effective at the Annual Meeting. The Governance and Sustainability Committee has recommended, and the Board has approved, the re-election of the eleven director nominees listed in Item 1 for the Annual Meeting. Each director nominee has informed the Board that he or she is willing to serve as a director. If any director nominee should decline or become unable or unavailable to serve as a director for any reason, your proxy authorizes the individuals named in the proxy to vote for a replacement nominee, or the Board may reduce its size.

PROFESSIONAL EXPERIENCE AND BACKGROUND • Mr. Dunbar most recently served as chief executive officer and chairman at Network Solutions, LLC, an IT service management company, from 2008 to 2010. • From 2004 to 2008, he served as president of global technology and operations for MasterCard where he was responsible for its global payments platform and operations. • Prior to that, he spent over a decade at Eli Lilly and Company where he served as president for the intercontinental region, vice president of information technology and chief information officer. • Mr. Dunbar graduated from Manchester University in the United Kingdom with a pharmacy degree and a master’s degree in business administration from Manchester Business School.

PROFESSIONAL EXPERIENCE AND BACKGROUND • Dr. Carmona has served as chief of health innovations of Canyon Ranch Inc., a life-enhancement company, since 2017. • He has also served in several other executive roles since joining Canyon Ranch in 2006, including vice chairman, chief executive officer of the Canyon Ranch health division and president of the nonprofit Canyon Ranch Institute. • Prior to Canyon Ranch, Dr. Carmona served as the 17th Surgeon General of the United States from 2002 through 2006, achieving the rank of Vice Admiral. Prior to serving as the Surgeon General, he was chairman of the State of Arizona Southern Regional Emergency Medical System and chief executive officer of the County Hospital and Healthcare System. • Dr. Carmona is a Laureate Professor of Public Health Policy and Administration at the University of Arizona. • Dr. Carmona also was a professor of surgery, public health, and family and community medicine at the University of Arizona, and surgeon and deputy sheriff of the Pima County, Arizona Sheriff’s Department.

• Ms. Martinez has received several distinctions for her leadership, including the No. 2 ranking on the ALPFA (Association for Latino Professionals for America) list of the 50 Most Powerful Latinas. • Ms. Martinez holds a bachelor’s degree in electrical engineering from the University of Puerto Rico and a master’s degree in computer engineering from Ohio State University. SKILLS AND QUALIFICATIONS Ms. Martinez brings to our Board leadership experience at leading technology companies, which enhances the Board’s depth of experience in business and digital transformation. She also brings a global leadership perspective, as well as a focus on customer success and customer experience. OTHER PUBLIC COMPANY BOARDS Current: Tyson Foods, Inc. Past Five Years: Cue Health Inc. (2021 - 2024)

There are 11 director nominees for election to the Board. The directors elected at the Annual Meeting will hold office until the 2025 Annual Meeting of Shareholders and until their successors have been elected and qualified, or until their earlier resignation, removal or death. Linda P. Mantia, who is no longer an independent director, and Susan R. Salka, who has served on the Board for almost ten years, will not be standing for re-election. Both of their terms will end effective at the Annual Meeting. The Governance and Sustainability Committee has recommended, and the Board has approved, the re-election of the eleven director nominees listed in Item 1 for the Annual Meeting. Each director nominee has informed the Board that he or she is willing to serve as a director. If any director nominee should decline or become unable or unavailable to serve as a director for any reason, your proxy authorizes the individuals named in the proxy to vote for a replacement nominee, or the Board may reduce its size.

• Mr. Ozan has a bachelor’s degree in accounting from the University of Michigan and a master’s degree in business from the Kellogg School of Management at Northwestern University. SKILLS AND QUALIFICATIONS Mr. Ozan brings to the Board considerable experience in the areas of finance, mergers and acquisitions, risk management and international operations having served as a former senior financial executive at a global company. OTHER PUBLIC COMPANY BOARDS Current: The Hershey Company Past Five Years: None

PROFESSIONAL EXPERIENCE AND BACKGROUND • Ms. Wilson-Thompson most recently served as executive vice president and global chief human resources officer of Walgreens Boots Alliance, Inc., a healthcare and retail pharmacy company, from December 2014 to January 2021, after serving as senior vice president and chief human resources officer from January 2010 to December 2014. • Previously, she served as senior vice president, global human resources and chief labor and employment counsel at Kellanova (formerly Kellogg Company). • Ms. Wilson-Thompson earned an A.B. degree from the University of Michigan, and J.D. and LL.M. (Corporate and Finance Law) degrees from Wayne State University. • Ms. Wilson-Thompson is also the immediate past chair of the board of directors of the University of Michigan Alumni Association.

PROFESSIONAL EXPERIENCE AND BACKGROUND • Mr. Hinton currently serves as an operating partner for the private equity firm Welsh, Carson, Anderson & Stowe. • From 2017 to 2021, he served as the CEO of Baylor Scott & White Health, the largest not-for-profit health system in Texas and one of the largest in the U.S. • Mr. Hinton joined Presbyterian Healthcare Services, New Mexico’s largest not-for-profit healthcare provider, in 1983 and he served as their CEO from 1995 to 2016. • During that time, he was a member of the American Hospital Association Board of Trustees and served as its Chair in 2014. • Mr. Hinton holds a master’s degree in healthcare administration from Arizona State University and a bachelor’s degree in economics from the University of New Mexico.

COMPANY STATEMENT IN OPPOSITION Your Board recommends a vote “AGAINST” this proposal for the following reasons: • The Board recognizes the value of strong independent Board leadership; currently, Don Knauss serves as independent Board Chair. • McKesson and its shareholders are best served when leadership choices are made by the Board on a case-by-case basis. • The Board regularly evaluates and reviews the Board’s leadership structure, a process which incorporates feedback from the Company’s shareholders. The Board recognizes the value of strong independent Board leadership; currently Don Knauss serves as independent Board Chair. An independent Board Chair has led our Board since 2019, when Brian Tyler became our CEO. Our Board elected Mr. Knauss as independent Board Chair in April 2022, succeeding the prior independent Board Chair, Edward Mueller, in a planned transition. McKesson and its shareholders are best served when leadership choices are made by the Board on a case-by-case basis. The Board believes continued flexibility to appoint the necessary Board leadership on a case-by-case basis is in the best interest of the Company and its shareholders. While the Board’s current practice is to elect an independent Board Chair, its directors have a fiduciary duty to regularly evaluate and determine the most appropriate Board leadership structure for McKesson and its shareholders in light of the Company’s evolving needs, circumstances and opportunities. Our current directors have deep knowledge of the strategic goals of the Company, the opportunities and challenges it faces, and the various capabilities of our directors and management. Therefore, the Board is best positioned to determine the most effective Board leadership structure, on a case-by-case basis, to protect and enhance long-term shareholder value. In situations where the Board Chair is not independent, McKesson’s Corporate Governance Guidelines require the appointment of a Lead Independent Director with clearly defined responsibilities to ensure strong independent governance functions and effective oversight of management. The Board opposes a prescriptive policy that would unnecessarily restrict its ability in structuring McKesson’s Board leadership as appropriate when faced with new or different circumstances. This proposal, if implemented, does not consider individual qualifications or if such a structure is the most suitable for the specific circumstances that the Board would need to consider. The rigid standard imposed by this proposal would deprive the Board of the flexibility to use its business judgment to select the most effective Board leadership structure to meet the needs of the Company and prioritize the interests of its shareholders based on the circumstances confronting the Board and the Company at any given time. The Board regularly evaluates and reviews the Board’s leadership structure, a process which incorporates feedback from the Company’s shareholders. The Board and the Governance and Sustainability Committee evaluate the Board’s leadership structure at least annually, and more frequently as appropriate. This process includes evaluating the performance of the current Board Chair and Board leadership structure generally to ensure strong independent governance and effective oversight of management. In addition, we regularly discuss our Board leadership structure with our shareholders as part of our year-round shareholder engagement program. Through these conversations, shareholders have not expressed concerns about our Board’s current ability to determine the appropriate Board leadership structure for the Company at any given time. The Board maintains effective independent oversight on behalf of our shareholders by ensuring that the Audit, Compensation and Talent, and Governance and Sustainability Committees are led by and composed entirely of independent directors. McKesson follows strong corporate governance practices as described in more detail beginning on page 11 of this proxy statement.

PROFESSIONAL EXPERIENCE AND BACKGROUND • Mr. Caruso retired as executive vice president and chief financial officer of Johnson & Johnson, a manufacturer of medical devices and pharmaceutical products, in August 2018, having served in the role since 2007. • He led the company’s financial and investor relations activities, as well as the procurement organization. • Mr. Caruso joined Johnson & Johnson in October 1999 as chief financial officer for Centocor, Inc., upon the completion of the merger of Centocor and Johnson & Johnson. • Prior to joining Centocor, he had varied industry experiences with KPMG. • Mr. Caruso was actively involved in government relations activities globally, including having served as co-chair of the U.S. Chamber of Commerce Global Initiative on Health and the Economy.

PROFESSIONAL EXPERIENCE AND BACKGROUND • Mr. Lerman currently serves as the executive vice president and chief legal officer of Starbucks Corporation, a company with a multinational chain of coffeehouses and roastery reserves. • Previously, Mr. Lerman served as the senior vice president, general counsel and corporate secretary of Medtronic plc, an American medical device company, from 2014 to January 2022. • At Medtronic, he led the company’s global legal, government affairs and ethics and compliance functions. Prior to Medtronic, Mr. Lerman served as executive vice president, general counsel and corporate secretary for the Federal National Mortgage Association (Fannie Mae). • Previous to Fannie Mae, he served as senior vice president, associate general counsel and chief litigation counsel for Pfizer. • Mr. Lerman also served as a litigation partner at Winston & Strawn LLP in Chicago and as an assistant U.S. attorney in the Northern District of Illinois.