UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): July 29, 2015

McKesson Corporation

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (415) 983-8300

Not Applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On July 29, 2015, at the Annual Meeting of Stockholders (the “2015 Annual Meeting”) of McKesson Corporation (the “Company”), stockholders reapproved the performance measures available under the Company’s Management Incentive Plan (the “MIP”) so that awards made under the MIP may continue to qualify as performance-based compensation under federal tax regulations. The MIP was amended by the Compensation Committee of the Board of Directors (the “Board”) at its May 26, 2015 meeting primarily to add two additional performance measures, which were subject to stockholder approval. A summary of the material terms of the MIP is set forth in the Company’s definitive proxy statement filed with the Securities and Exchange Commission (the “SEC”) on June 15, 2015 (the “Definitive Proxy Statement”). A copy of the MIP is attached hereto as Exhibit 10.1 and incorporated herein by reference.

At the 2015 Annual Meeting, stockholders approved amendments to the Company’s Amended and Restated By-Laws to allow eligible stockholders to place their own director nominees on the Company’s proxy card, along with the candidates nominated by the Board (the “Proxy Access By-Law Amendments”). The Proxy Access By-Law Amendments specify a three-percent/three-year holding requirement for eligibility and state that an eligible stockholder or group of stockholders who complies with the specified procedural and disclosure requirements may include stockholder-nominated director candidates in the Company’s proxy materials to fill up to 20% of the available board seats. A summary of the Proxy Access By-Law Amendments is set forth in the Company’s Definitive Proxy Statement. A copy of the Amended and Restated By-Laws is attached hereto as Exhibit 3.1 and incorporated herein by reference.

On July 29, 2015, the following seven items were voted on at the 2015 Annual Meeting, and the stockholder votes on each such matter, as certified by the Inspector of Election, are set forth below.

Item 1. The Board of Directors’ nominees for directors, as listed in Company’s Definitive Proxy Statement, were each elected to serve a one-year term. The votes were as follows:¹

Item 2. The appointment of Deloitte & Touche LLP as the Company’s independent registered public accounting firm for the fiscal year ending March 31, 2016 was ratified, having received the following votes:²

Item 3. The proposal to approve, on an advisory basis, the compensation of the Company’s named executive officers was approved, having received the following votes:²

Item 4. The proposal to reapprove the performance measures available for performance-based awards under the Company’s Management Incentive Plan was approved, having received the following votes:³

Item 5. The proposal to amend the Company’s By-Laws to permit shareholder proxy access was approved, having received the following votes:⁴

Item 6. The stockholder-submitted proposal on disclosure of political contributions and expenditures was not approved, having received the following votes:²

Item 7. The stockholder-submitted proposal on accelerated vesting of equity awards was not approved, having received the following votes:²

Each of the items considered at the 2015 Annual Meeting is described in further detail in the Definitive Proxy Statement. No item other than the seven items addressed above and described in the Definitive Proxy Statement was submitted at the 2015 Annual Meeting for stockholder action.

(d) Exhibits.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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