401(K) Retirement Savings Plan Summary Plan Description Effective April 1, 2021

401(k) Retirement Savings Plan Summary Plan Description Effective April 1, 2021

Introduction

The McKesson Corporation 401(k) Retirement Savings Plan (the “Plan”) is intended to provide you the unique opportunity to set aside tax-deferred retirement savings through convenient payroll deductions while reducing your federal and state income taxes. With a McKesson matching contribution to supplement your own savings, the Plan can help you achieve your individual financial goals more quickly. You have significant flexibility and choice: whether or not to make contributions, how much to contribute and where to invest. The availability of loans and hardship withdrawals means that you have access to your Plan funds if your circumstances change. Your Plan account is fully portable and allows you to change jobs without a loss in retirement benefits.

Provisions of the Plan are summarized in this summary plan description (SPD). This description does not state all plan terms and conditions. The information provided here does not cover every situation and is not intended to replace the plan document — or to change its meaning. In all cases, the plan document — and not this summary — will govern benefits paid under the Plan.

We hope that the information provided in this SPD will answer most of the questions you have regarding your Plan benefits. When you need assistance or have specific questions, log on to www.netbenefits.com or call 888.625.7747.

2 What’s Inside

Plan Highlights Distributions Following Employment 4 Plan Highlights 18 Distributions Following Employment 18 Distribution Upon Death Eligibility & Enrollment 6 Excluded Classes Payment Options and How to Request a 6 Enrolling Distribution 7 Automatic Enrollment 19 Payment Options 7 Choosing Your Beneficiaries 19 How to Request a Distribution 7 Plan Employers Tax Consequences of Plan Payments Your Plan Contributions 20 Tax Consequences of Plan Payments 8 Elective Deferrals 20 Mandatory Income Tax Withholding 8 Pre-Tax Deferrals 20 Rollovers and Direct Rollovers 8 Roth Deferrals 21 Net Unrealized Appreciation 9 After-Tax Contributions 21 State Taxes 9 Changing Your Contribution Amounts 21 Excise Tax on Early Distributions or Withdrawals 9 Rollover Contributions 21 Roth Conversions 9 IRS Limits 21 Tax Advice and Changes in Tax Laws Matching Contributions Additional Information 10 Matching Contributions 22 Filing a Claim 22 Appealing a Claim Denial Vesting 23 Losing Your Benefits 11 Vesting 23 Assignment or Pledge of Interest 23 No Employment Contract Plan Investments 23 No Pension Insurance 12 Plan Investments 24 Termination, Amendment and Suspension 13 The Importance of Diversifying Your 24 Special Plan Provisions and Inactive Accounts Retirement Savings 24 Maintenance of Plan Records 13 Initial Investment Instructions 24 Account Maintenance Fees 13 Changing Your Investment Elections Plan Administration Information 13 Default Investment 14 Keeping Track of Your Investments 25 Plan Administration Information 14 Dividends on McKesson Stock 14 Voting and Tender of Shares of McKesson Stock Your Rights as a Plan Participant 14 Status as Eligible Individual Account & ERISA § 26 Right to Information 404(c) Plan 26 Denied Claim 26 Enforcing Your Rights Access to Plan Accounts While an Employee 26 Questions 15 Loans 15 Loans of Moneys from Predecessor Employers’ Plans Administrative Facts 15 Withdrawals 27 Administrative Facts 16 Hardship Withdrawals 16 Withdrawals After Age 59½ 16 Qualified Reservist Distributions 17 Rollover Accounts 17 Withdrawal of Legacy After-Tax Contributions 17 No Withdrawals from Certain Accounts 17 Withdrawal of Amounts Under Predecessor Employers Plans

3 Plan Highlights

Plan Highlights

The Plan is a long-term savings plan designed to provide savings for your retirement years, but there is more. Before enrolling, please read this SPD carefully. Here’s a look at what the Plan has to offer:

Eligibility Employee Contributions — After-Tax Contributions If you’re a regular McKesson employee, you’re eligible to participate on the first of the month You may elect to contribute 1% to 25% of your after completing 2 months of service. If you’re a eligible compensation to the Plan as After-Tax casual employee, you’re eligible to participate on Contributions. You can change your contribution the first of the month after completing (1) one year percentage at any time. Any change that you make of service (generally, a 12 month period during will be reflected in the next pay period (or as soon which you are credited with at least 1,000 hours as administratively practicable thereafter). of service); or (2) if earlier, three (3) consecutive one-year periods starting after Dec. 31, 2020 during each of which you’ve been credited with at least McKesson Matching Contributions 500 hours of service. You’re a casual employee if McKesson will match your Elective Deferrals by you’re regularly scheduled to work less than 20 making a Matching Contribution of $1 for each hours per week or if you’re classified by McKesson $1 you contribute as Elective Deferrals up to 3% as a seasonal, temporary, or casual employee. of your pay and 50¢ for each $1 you contribute as Elective Deferrals on the next 2% of your Employee Contributions — Elective pay. Elective Deferrals of more than 5% of your Deferrals & Automatic Enrollment pay, Catch-Up Contributions and After-Tax Contributions are not matched. You may elect to contribute 1% to 75% of your eligible compensation to the Plan as Elective Rollover Contributions Deferrals subject to IRS limits. There are two types of Elective Deferrals that you can make to the Plan: If you have a balance in a former employer’s Pre-Tax Deferrals and after-tax Roth Deferrals. You retirement plan or an IRA, you may be eligible to can change your contribution percentage at any consolidate your assets by rolling those amounts time. Any change that you make will be reflected in into the Plan. the next pay period (or as soon as administratively practicable thereafter). Roth In-Plan Conversion If you do not make an election to contribute when you are first eligible to participate in the Plan, The Plan gives you the flexibility to convert certain you will be automatically enrolled in the Plan Plan After-Tax sub accounts into after tax Roth and will have five percent (5%) of your eligible accounts. Converted balances are credited to a compensation for each payroll period contributed Roth In-Plan Conversion sub-account. on your behalf as Pre Tax Deferrals. At any time, you can make an affirmative election to participate Your Plan Account at a different rate (including 0%). Your Elective Deferrals, After-Tax Contributions and McKesson’s Matching Contributions are credited to your Plan account. Your Plan account is made up of sub-accounts credited with contributions according to source and contribution type.

4 Plan Highlights

Vesting Distributions After McKesson Employment Your Elective Deferrals, McKesson Matching Contributions and After Tax Contributions are When you are no longer employed by McKesson, 100% vested immediately. you are entitled to receive the vested portion of your Plan account (1) as a lump sum, (2) in Investment Options partial withdrawals, or (3) in monthly, quarterly, semi-annual or annual installments of an You have a wide range of investment options approximately fixed or a variable value over a allowing you the flexibility to create a diversified period of time not to exceed your remaining portfolio which meets your retirement goals. You lifetime or the joint remaining lifetime of you and may invest your Plan account among Core Options, your spouse. If your account balance is $1,000 or Target Retirement Date Options and Fidelity less, your account will be automatically paid out in BrokerageLink® investments. If you do not provide a lump sum. investment direction, your contributions will be invested in the age appropriate Target Retirement Administration Fee Date Option. You will be charged an account maintenance fee Loans of $9.50 per quarter ($38.00 per year). This fee is automatically deducted from your account and While you are a McKesson employee, you may will show as a separate line item on your quarterly take out a loan against your Plan account. There statement. is $35 loan origination fee and a $15 annual loan maintenance fee. You may have only one loan Additional Information outstanding at any time. For additional information, log on to Access to Your Plan Account While www.netbenefits.com or call 888.625.7747. Employed by McKesson

To help ensure that money is there when you are ready to retire, current tax laws restrict withdrawals from the Plan. Other than Plan loans, your access to Plan funds while you are an employee is limited to withdrawals that are permitted under certain circumstances. Withdrawals and distributions are subject to income taxes and possible early withdrawal penalties if you do not roll them over to another employer’s qualified retirement plan, an IRA or a Roth IRA.

5 Eligibility & Enrollment

If you’re a regular McKesson employee scheduled to work at Excluded Classes least 20 hours per week and not in any of the excluded classes described below, you’re eligible to participate in the Plan on the An individual is not eligible to participate in the Plan for any first day of the month after completing 2 months of service. period of time that they are:

If you’re a casual employee, you’re eligible to participate in the • a leased employee, Plan on the first day of the month following the earlier of: • a member of a collective bargaining unit (unless the • your completion of one year of service, which is a 12-month collective bargaining agreement provides for participation period in which you complete at least 1,000 hours of in the Plan), service; or • a non-resident alien with no U.S. source income, • your completion of three (3) consecutive 12-month periods beginning after Dec. 31, 2020 during each of which you • an employee of any business unit or McKesson entity that complete at least 500 hours of service. is not designated as participating in the Plan,

You’re a casual employee if: • an employee covered by a defined contribution plan sponsored by McKesson or any of its affiliates, or • you’re a part-time employee scheduled to work less than 20 hours per week; or • in any other excluded class described in the Plan document. • you’re designated by McKesson as a seasonal, temporary or casual employee. Enrolling

A “seasonal” employee means an individual hired to work for You will be sent an enrollment package approximately one a portion of each year on a repetitive basis in a job designed month before becoming eligible for Plan participation. If you to cover a seasonal operating need. A “temporary” employee are rehired, you will be sent an enrollment package shortly means an individual hired to work for a limited period of time after rehire. If you are a casual employee, you will be sent to perform a specific project with the understanding that once an enrollment package after your completing the eligibility the project is complete his services will no longer be required by requirements. McKesson. Your enrollment materials will include directions for enrolling. You may begin Plan participation with the first available To enroll, you can log on to www.netbenefits.com or call paycheck coinciding with or next following the date 888.625.7747. you become eligible (or as soon as administratively You may elect to make Elective Deferrals (Pre-Tax and/ practicable thereafter). or Roth Deferrals), After-Tax Contributions, and Catch-Up If you are rehired and have already satisfied the eligibility Contributions (Pre-Tax and/or Roth Deferrals) if you are eligible requirements, you will be eligible to participate in the Plan as beginning as of the payroll period coinciding with or next soon as administratively practicable after your date of rehire. following the date you become eligible by authorizing a payroll deduction. To do so, you will designate the percentage of pay to be contributed to the Plan (see “Your Plan Contributions” on p. 8) and name a beneficiary (see “Choosing Your Beneficiaries” below). Your enrollment must be submitted within the time and in the manner prescribed by McKesson and described in your enrollment materials.

6 Eligibility & Enrollment

Automatic Enrollment

If you first become eligible for Plan participation or are rehired on or after Jan. 1, 2019, you are automatically enrolled in the Plan and will have five percent (5%) of your eligible compensation for each payroll period contributed on your behalf as Pre-Tax Deferrals. Automatic Pre Tax Deferrals will start as soon as administratively feasible following the date you become eligible to participate and after you have received advance notice that you are going to be automatically enrolled. You may elect at any time not to contribute to the Plan, or to defer a different percentage of your eligible compensation. Choosing Your Beneficiaries

When you become a participant, you will need to designate a beneficiary to inform McKesson who should receive payment of your Plan account in the event of your death. If you are married and you die, federal law generally entitles your spouse to receive your account. You may name someone other than your spouse as your primary beneficiary, but only if your spouse gives a written, notarized consent to your designation. If you are single, die before you retire, and have not named a beneficiary, your account will be paid to your estate. Plan Employers

The employers under the Plan are McKesson Corporation and those of its subsidiaries or affiliates designated by the Board of Directors of McKesson to participate in the Plan. Unless indicated otherwise, “McKesson” refers to McKesson Corporation and each participating Plan Employer. Service you complete with a McKesson subsidiary or affiliate will be treated as service with McKesson.

7 Your Plan Contributions

Elective Deferrals Pre-Tax Deferrals

You may contribute 1% to 75% of your eligible compensation to Pre-Tax Deferrals are not subject to current income tax and the Plan as Elective Deferrals. There are two types of Elective are exempt from federal and state income tax withholding. As Deferrals that you can make: Pre-Tax Deferrals and Roth a result, your current taxable income — the amount on which Deferrals. A single IRS limit ($19,500 for 2021 and as adjusted you pay taxes — is reduced, saving you current tax dollars. in later years by the IRS) applies to Elective Deferrals (Pre-Tax Your Pre-Tax Deferrals and earnings on these deferrals are Deferrals, Roth Deferrals or a combination of both) for each tax-deferred and are not subject to income tax until a later time calendar year. If you are age 50 or older at any time during a when they are distributed to you. calendar year, you can contribute up to an additional $6,500 in Catch-Up Contributions (as Pre-Tax Deferrals, Roth Deferrals or For example, if you earn $40,000 in a particular year and elect a combination of both) for that calendar year. to make Pre-Tax Deferrals to the Plan of $4,000, you only recognize $36,000 in income on that year’s tax return. This Your Elective Deferrals are put into one of the four following would represent a $1,000 current tax savings. You ultimately sub-accounts: (1) Pre-Tax Deferrals sub-account; (2) Roth pay income taxes on your Pre-Tax Deferrals and earnings when Deferrals sub-account; (3) Pre-Tax Employee Catch-Up they are distributed to you, generally during retirement when sub-account; and (4) Roth Catch-Up sub-account. your income tax rates may be lower.

Your eligible compensation includes all cash wages reported Roth Deferrals on your Form W-2 except (1) reimbursements and expense allowances, (2) fringe benefits (cash and noncash), such Roth Deferrals are subject to federal and state income tax and as amounts realized from the exercise of stock options, employment taxes at the time they are contributed. Their tax moving expenses, welfare benefits, imputed interest from treatment when coming out of the Plan is different from that below-market-rate loans and compensation previously deferred, of distributions of Pre-Tax Deferrals. A Roth distribution is (3) payments under a McKesson long-term incentive plan, qualified if it is made after the five-year period beginning on (4) extraordinary payments not made under McKesson’s regular Jan. 1 of the first year that you made either a Roth Deferral bonus program such as signing and retention bonus payments, or a Roth conversion (see p. 21) under the Plan and is either and (5) amounts paid after your termination of employment (1) made on or after the date you attain age 59½, (2) made after with McKesson, e.g., severance payments. Your eligible your death, or (3) attributable to your being disabled. If the compensation does not include any compensation paid after distribution is qualified, no income tax is due on either the you terminate employment with McKesson and have been paid Roth Deferrals or earnings distributed from the Roth account. If your last paycheck. the distribution is not qualified, income tax will be due on the portion attributable to earnings.

8 Your Plan Contributions

After-Tax Contributions Rollover Contributions

You may elect to contribute 1% to 25% of your eligible Keeping your retirement savings in a single plan can help compensation to the Plan as After-Tax Contributions. simplify paperwork and investment performance tracking. If After-Tax Contributions are subject to federal and state income you are currently a McKesson employee, the Plan will accept tax and employment taxes at the time they are contributed. rollovers from the following sources: Earnings on After-Tax Contributions are tax deferred and are not subject to income tax until a later time when they are • Pre-tax, after-tax and Roth amounts from tax-qualified distributed to you. If you convert your After-Tax Account into plans (e.g., 401(k) plans and 401(a) defined benefit plans) a Roth In-Plan Conversion sub-account (see p. 21), earnings and from 403(b) plans. on your contributions are distributed tax free if paid in a Roth • Pre-tax and taxable amounts from governmental 457(b) qualified distribution. Under special IRS nondiscrimination plans, traditional IRAs and SIMPLE IRAs (after you have rules, the maximum amount you may contribute may be participated in the SIMPLE IRA for two years). a lower percentage. In order to meet these rules, After-Tax Contributions may be returned to you. You will be notified if A rollover of after-tax dollars and Roth 401(k)/403(b) deferrals your contributions will be returned. (excluding earnings) must be made by direct rollover to the Plan. Earnings on Roth 401(k)/403(b) deferrals (the taxable The decision whether to make Pre-Tax Deferrals, Roth Deferrals portion) may be rolled into Plan using an indirect/60-day or After-Tax Contributions is complex. You may wish to consult rollover. Roth 401(k)/403(b) deferrals can only be rolled in a a personal tax adviser. There are a number of factors to consider Plan Roth account. Rollovers from Roth IRAs are not accepted. such as your current income tax rates relative to your projected For more information, log on to www.netbenefits.com or call income tax rates when you retire (or whenever you expect to 888.625.7747. receive a distribution from the Plan), the amount of investment earnings you expect to accumulate, how long you expect to keep IRS Limits your Elective Deferrals in the Plan and whether you expect to keep Roth Deferrals in the Plan until you are eligible for a Roth In addition to the IRS limitation on Elective Deferrals, the qualified distribution. maximum amount of a participant’s annual compensation that may be taken into account under the Plan in any Plan Changing Your Contribution Amounts Year (April 1 through March 31) is subject to a specified limit of $290,000. The aggregate amount of contributions (including You may change, suspend or renew at any time the percentage Elective Deferrals, After Tax Contributions, and Matching of pay you are contributing. Any change that you make will Contributions that may be added to your Plan account in any be reflected in the next available pay period (or as soon as Plan Year is limited to $58,000.* In addition, the aggregate administratively practicable thereafter). amount of Elective Deferrals (not including Catch Up Contributions) and After-Tax Contributions that may be added to your Plan account in any Plan Year is limited to $46,400.*

These IRS limits may require a reduction in the contributions elected by or provided to you as a Plan participant. McKesson calculates all of these contribution limits annually and monitors them throughout the year. If you are found to have exceeded any of these limits, you will be contacted, and appropriate action will be taken in accordance with the Plan’s provisions and applicable law. However, if you participate in more than one employer’s plan during the year, it is your responsibility to make sure you stay within the legal limits described above.

* Subject to cost of living increases. 9 Matching Contributions

Matching Contributions For example, assume your annual eligible compensation is $50,000. You elect to make Elective Deferrals at a rate of 10% On your behalf, McKesson will allocate to the Plan an amount for the first half of the Plan Year and then elect to make Elective equal to 100% of the first 3% of your pay that you contribute as Deferrals at the rate of 0% for the second half of the Plan Year. Elective Deferrals and 50% of the next 2% of your pay that you During the first 6 months, your Elective Deferrals are $2,500 contribute as Elective Deferrals. This means that McKesson ($25,000 x 10%) and your account is credited with a Matching makes a Matching Contribution of up to 4% of eligible Contribution of $1,000 ($25,000 x 4%). During the second 6 compensation to your account when you contribute at least 5% months of the Plan Year, your Elective Deferrals are $0 and of your eligible compensation as Elective Deferrals to the Plan. your account is credited with a Matching Contribution of $0. In this case, you make total Elective Deferrals of $2,500 and are For example, assume your eligible compensation is $2,000 credited a total Matching Contribution of $1,000. At the end per pay period and you elect to make Elective Deferrals at the of the Plan Year, your Elective Deferral rate for the year is 5% rate of 5% of pay. For each pay period, you will make Elective ($2,500/$50,000) and the Matching Contribution determined Deferrals of $100 ($2,000 x 5%). For the first 3% of your pay on an annualized basis is $2,000 ($50,000 x 4%). The annual that you contribute, your account is credited with a Matching Matching Contribution ($2,000) exceeds the Matching Contribution of $60 ($2,000 x 3%). For the next 2% of your pay Contribution of $1,000 already credited to your account that you contribute, your account is credited with a Matching during the Plan Year. Your account is credited with a true-up Contribution of $20 ($2,000 x 2% x 50%). For each payroll contribution of $1,000 so that your account is credited with period, you are credited with a total Matching Contribution of a Matching Contribution based on your total annual eligible $80 (or 4% of pay). compensation for the Plan Year.

Elective Deferrals in excess of 5% of pay and After-Tax Matching Contributions are made in cash and are invested in Contributions are not matched. Also, Catch-Up Contributions accordance with the same investment instructions that apply to are not matched unless they are later reclassified as regular your Elective Deferrals. Elective Deferrals. Catch-Up Contributions may be reclassified as regular Elective Deferrals if they do not exceed a limit under McKesson may amend the Plan, at any time during the the terms of the Plan or an IRS limit (e.g., the $19,500 IRS limit plan year, to reduce or eliminate matching contributions. If described on p. 8). McKesson amends the Plan to reduce or eliminate matching contributions during the plan year, McKesson will provide you The Matching Contribution will be allocated to your Plan a notice and the suspension or reduction will not apply until at account as soon as administratively practicable following each least 30 days after that notice is provided. pay period or such other period as determined by McKesson.

McKesson may make a Matching Contribution after the end of the Plan Year (April 1 to March 31) in order for you to receive your full match based on the 4% annual limit (called a “true-up” contribution). The true-up contribution will be made to your account if your Matching Contribution determined on an annual basis exceeds the Matching Contribution already made to your account during the Plan Year. Any true-up contribution that you receive for a particular Plan Year will be credited to your Additional Company Match sub-account and is treated in the same manner under the Plan as other Matching Contributions.

10 Vesting

Vesting

Being “vested” in contributions under the Plan means you have an unconditional guaranteed right to those contributions, subject to any applicable distribution and/or withdrawal restrictions.

Elective Deferrals, After-Tax Contributions and McKesson Matching Contributions made under the Plan are 100% vested at all times. If you had an account balance under an acquired company’s 401(k) plan that was merged into the Plan, that account may continue to vest under the Plan according to the vesting schedule that applied under the prior plan.

11 Plan Investments

Plan Investments • Vanguard® Target Retirement 2035 Trust Plus

To help you make the most of your retirement savings, the • Vanguard® Target Retirement 2040 Trust Plus Plan offers a wide range of investment options. This flexibility • Vanguard® Target Retirement 2045 Trust Plus provides you with the opportunity to create a diversified investment portfolio that’s right for you based on your • Vanguard® Target Retirement 2050 Trust Plus investment objectives and tolerance for risk, your knowledge and experience with investments, and your time available to • Vanguard® Target Retirement 2055 Trust Plus monitor your investments. Log on to www.netbenefits.com or call 888.625.7747 to review the participant disclosure notice, the • Vanguard® Target Retirement 2060 Trust Plus 401(k) Plan Enrollment Guide and other materials that contain • Vanguard® Target Retirement 2065 Trust Plu the latest, up-to-date information about investment options available under the Plan. As of the date of this SPD, the Plan’s Fidelity BrokerageLink® investment options are the following Fidelity BrokerageLink® allows you to choose from investments Core Options: in addition to the Core Options and Target Retirement Date Options, such as mutual funds, stocks, corporate bonds • McKesson Large Cap Growth Portfolio and U.S. Treasury Securities. This feature is intended for • State Street S&P 500 Index Fund investors who are comfortable actively managing a portfolio of expanded investment choices. McKesson does not provide any • Dodge & Cox Large Cap Value Portfolio management oversight with respect to Fidelity BrokerageLink® investments. • McKesson Small Cap Growth Portfolio

• Fisher Investments Small Cap Value Portfolio

• McKesson International Equity Portfolio

• McKesson Bond Portfolio

• BNY Mellon Stable Value Portfolio

• McKesson Employee Stock Fund

The McKesson Employee and Employer Stock Funds are frozen to new investments. No new contributions, loan repayments, or investment exchanges are allowed into these Funds. Any existing balances in these Funds can remain in the Funds or you may exchange all or a part of your balance in the Fund into one or more of the other investment options.

Target Retirement Date Options: • Vanguard® Target Retirement Income Trust Plus

• Vanguard® Target Retirement 2015 Trust Plus

• Vanguard® Target Retirement 2020 Trust Plus

• Vanguard® Target Retirement 2025 Trust Plus

• Vanguard® Target Retirement 2030 Trust Plus

12 Plan Investments

The Importance of Diversifying Your Initial Investment Instructions Retirement Savings You can make your initial investment choices by logging onto To help achieve long-term retirement security, you should www.netbenefits.com or calling 888.625.7747. You may invest give careful consideration to the benefits of a well-balanced your savings in any percentage increment, as long as the and diversified investment portfolio. Spreading your assets combination adds up to 100%. For example, you may put 25% in among different types of investment options can help you one option, 33% in a second, and 42% in a third. achieve a favorable rate of return, while minimizing your overall risk of losing money. This is because market or other Changing Your Investment Elections economic conditions that cause one category of assets, or one In addition to selecting options, you have a number of particular security, to perform very well often cause another choices when you change your investments. You can specify asset category, or another particular security, to perform whether your elections apply to (1) current holdings only; poorly. If you invest more than 20% of your retirement savings (2) future contributions only; or (3) both current holdings and in any one category or industry, your savings may not be future contributions. You may also choose to invest your properly diversified. Although diversification is not a guarantee Pre-Tax Deferrals differently than your Roth Deferrals and against loss, it is an effective strategy to help you manage Matching Contributions. investment risk. You can rebalance your entire Plan account by electing to In deciding how to invest your retirement savings, you should change your current holdings only. Changes are generally take into account all of your assets, including any retirement effective on the day of the election or the following business day savings outside of the Plan. No single approach is right for depending on the time of day that you make your election. everyone because, among other factors, individuals have different financial goals, different time horizons for meeting Default Investment their goals, and different tolerances for risk. Therefore, you should carefully consider the rights described in this SPD and If you do not provide investment direction, your contributions how these rights affect the amount of money that you keep (including automatic contributions to the Plan if you have been invested in the McKesson Employer and McKesson Employee automatically enrolled) and any Matching Contributions will be Stock Funds. invested in the age appropriate Target Retirement Date Option (listed on p. 12). Your Target Retirement Date Option is based It is also important to periodically review your investment on the year closest to the year that you will attain age 65. You portfolio, your investment objectives, and the investment can change your investment of these contributions at any time options under the Plan to help ensure that your retirement in accordance with the procedures described above. However, savings will meet your retirement goals. To review available unless you provide alternative direction, your contributions will investment education tools, log onto www.netbenefits.com. continue to be invested in this default investment option.

For a description of the investment alternatives and the investment objectives and risk and return characteristics of each alternative, including information relating to the type and diversification of assets within the portfolio of each investment alternative, please refer to the McKesson 401(k) Plan Enrollment Guide at Fidelity NetBenefits.

13 Plan Investments

Keeping Track of Your Investments Status as Eligible Individual Account & ERISA § 404(c) Plan You can log on to www.netbenefits.com or call 888.625.7747 to get current and year-to-date investment results for all options. The Plan is an employee stock ownership plan (an “ESOP”) and also an eligible individual account plan under the Employee You can obtain your Plan statement online at any time. Retirement Income Security Act of 1974 (“ERISA”). This The statement shows the beginning and ending balance, means that it is specifically designed to invest in McKesson your vested account balance and any other transactions stock and, as a result, the diversification requirement and affecting your account. It also shows the amount of Elective prudence requirement (to the extent it requires diversification) Deferrals, After-Tax Contributions and McKesson Matching under ERISA are not violated by the acquisition or holding Contributions along with the investment options’ performance of McKesson stock. Participants are solely responsible for during the year. any investment losses incurred as a result of investments in Dividends on McKesson Stock McKesson stock. Also, the Plan is a plan which is described in ERISA Section The dividends on the McKesson stock held in your McKesson 404(c) under which each participant exercises control Employer Stock Fund and Employee Stock Fund accounts will over the assets in his accounts and shall be provided the be automatically reinvested in shares of McKesson stock, unless opportunity to choose, from a broad range of investments, you elect to have those dividends paid directly to you in cash, in the manner in which the assets in his or her Plan accounts accordance with procedures established by McKesson. are invested. No person who is otherwise a fiduciary of In the event of a capital adjustment resulting from a stock Plan shall be liable for any loss which results from such dividend, stock split, reorganization merger, consolidation or a exercise of control, whether by the participant’s affirmative combination or exchange of shares, shares of stock held in the direction or failure to direct an investment. For purposes of McKesson Employer Stock Fund and McKesson Employee Stock ERISA Section 404(c), self-directed brokerage investments Fund will be appropriately adjusted. are not designated investment alternatives, and no Plan fiduciary shall have the obligation to monitor or evaluate the Voting and Tender of Shares of McKesson Stock prudence of such investments.

Participants in the Plan are entitled to instruct the Trustee on a confidential basis (1) how to vote all shares of McKesson stock allocated to their accounts under the Plan, and (2) the manner in which the Trustee is to respond to a tender or exchange offer with respect to any or all shares of McKesson stock allocated to their accounts under the Plan. The Trustee votes the shares as instructed by participants. If no instructions are received with regard to shares of McKesson stock in a participant’s inactive PAYSOP account, such shares will not be voted. Any other shares of McKesson stock as to which the Trustee receives no voting instructions are voted by the Trustee in the same proportion as shares for which instructions are received. In the event of a tender or exchange offer and if, and to the extent that the Trustee shall not have timely received instructions from any participant (or beneficiary) with a right to instruct, such person shall be deemed to have timely instructed the Trustee not to tender or exchange the relevant shares of McKesson stock.

14 Access to Plan Accounts While an Employee

Although the Plan is intended primarily as a vehicle for If you are on an unpaid leave of absence, including a military long-term savings, you can gain access to all or portions leave, your loan will be re amortized so that it is repaid on a of certain of your sub-accounts while an active McKesson monthly basis. Fidelity will notify you of the monthly loan employee under specified circumstances. Access to Plan payment amounts. You will be asked to make loan payments sub-accounts is available through loans and withdrawals. using ACH through your bank. When you return from leave, your loan will be re-amortized so that your loan payments are Loans made through payroll on your regular pay dates. While you are an employee of McKesson, you may borrow from Loans of Moneys from Predecessor your Plan account for any reason and pay the principal, plus Employers’ Plans interest, back to your own Plan account. The minimum you can borrow is $1,000. The maximum you can borrow is the Certain participants who had accounts in plans of predecessor lowest of: employers which were merged into the Plan may be subject to different rules with respect to loans from the portion of their • 50% of the total vested value of your Plan account; Plan accounts attributable to their interests in the prior plan. • $50,000 less your highest outstanding loan balance in the Withdrawals 12 months preceding your loan application; or The special tax benefits allowed for plans like the Plan are • The total value of your sub-accounts credited with offered to encourage you to save for the future. To help ensure Elective Deferrals (including Pre-Tax, Roth and that money is there when you are ready to retire, current Catch-Up contributions), After-Tax Contributions and tax laws restrict withdrawals of this money during your Rollover Contributions. working years.

There is a $35 loan origination fee and a $15 annual loan Other than Plan loans, your access to Plan funds while you are maintenance fee. The interest rate is the Prime rate, as an employee is limited to withdrawals that are permitted under published in The Wall Street Journal on the last day of the certain circumstances. The types of withdrawals possible for preceding month, plus 1%. The interest rate is fixed for the employees are: entire term of the loan. You are allowed only one loan at a time. You can choose a repayment term from 1 to 5 years; • Financial hardship withdrawals in the case of a residential loan, you are permitted a 10-year repayment term. • Withdrawals after age 59½

Your loan and the interest are repaid to your Plan account • Rollover Contribution withdrawals through easy, automatic payroll deductions. If you choose, you • Qualified Reservist Distributions can repay the loan in full at any time. • Withdrawals of legacy After-Tax Contributions If you leave McKesson before your loan has been fully repaid, you can choose to repay your loan in full, continue to repay All withdrawals are subject to a $500 minimum. Withdrawals in installments through automated clearing house (ACH) shall be made from the applicable sub-accounts available for or have your outstanding loan balance deducted from your such withdrawals in such order as prescribed by McKesson. If Plan balance. You are responsible for ensuring your ACH a withdrawal is made from a sub-account which is invested in information is current and that your payments are made on a more than one investment option, the amount withdrawn shall timely basis. If you take a distribution of your account balance, be charged to each investment in the same proportion as the your outstanding loan will be defaulted. Therefore, if you want sub-account is invested in such investment option. to continue paying off your loan, you must leave a small balance in your account. Keep in mind that distributions are taxable, and if your loan is considered a distribution, you may be subject to an additional tax penalty.

15 Access to Plan Accounts While an Employee

Hardship Withdrawals • Expenses for the repair of damage to your principal residence that would qualify for the casualty deduction You may withdraw amounts in your sub-accounts credited on your federal tax return (disregarding whether the loss with Elective Deferrals (including Pre-Tax, Roth and Catch-Up exceeds 10% of adjusted gross income and the provision Contributions), regular After-Tax Contributions, legacy After- that limits the casualty deduction to losses attributable to a Tax Contributions and Rollover Contributions while you are federally declared disaster) working if you have a financial hardship, and the withdrawal is necessary in light of your own immediate and heavy • Expenses and losses (including loss of income) you incur financial needs. on account of a disaster declared by the Federal Emergency Management Agency (FEMA) under the Robert T. Stafford You can withdraw only up to the amount you need to meet Disaster Relief and Emergency Assistance Act provided that the financial hardship and only to the extent the money is not your principal residence or principal place of employment reasonably available from other sources. You can only take a at the time of the disaster was located in an area designated hardship withdrawal if: by FEMA for individual assistance with respect to the disaster • You have obtained any other currently available distributions under the Plan (except hardship withdrawals) For these purposes, your “primary beneficiary” is an individual and any other plan of deferred compensation, whether named in your beneficiary designation form who has an qualified or nonqualified, maintained by McKesson or any unconditional right to all or a portion of your account after of its affiliates, and your death.

• You represent in writing (including through an electronic McKesson’s decision about your hardship withdrawal request medium) that you have insufficient cash or other liquid will specify the amount that may be withdrawn and will be final assets reasonably available to satisfy the financial need and binding on all interested parties. (and McKesson does not have actual knowledge to the contrary). Withdrawals After Age 59½

If you are under age 59½, you may be required to pay a 10% When you reach age 59½, you may withdraw in cash all federal tax penalty, in addition to ordinary federal income taxes. or a part of amounts in your sub accounts credited with Elective Deferrals (including Pre-Tax, Roth and Catch-Up You can take a hardship withdrawal only for the Contributions), regular After-Tax Contributions, legacy following purposes: After-Tax Contributions, and Rollover Contributions for any reason — even if you are still an active employee of McKesson. • Costs directly related to the purchase of your principal residence (excluding mortgage payments) Qualified Reservist Distributions

• Post-secondary tuition, related educational fees, and room If you are ordered or called to active duty for a period in excess and board for the next 12 months for you, your spouse, your of 179 days or for an indefinite period of time by reason of being dependents and your primary beneficiary a member of a reserve component (as defined in section 101 of title 37, United States Code), you may, during your period • Medical expenses not covered by insurance for you, your of employment with McKesson beginning on the date of the spouse, your dependents and your primary beneficiary order or call to active duty and ending at the close of the active duty period, withdraw in cash all or a part of amounts in • Payments necessary to prevent your eviction from your your sub-accounts credited with Elective Deferrals (including principal residence or foreclosure on the mortgage on Pre-Tax, Roth and Catch-Up Contributions), prior After-Tax that residence Contributions, and Rollover Contributions. • Payments for burial or funeral expenses for your deceased parent, spouse, children, dependents or primary beneficiary

16 Access to Plan Accounts While an Employee

Rollover Accounts

During your employment with McKesson you may withdraw in cash all or a part of amounts in your sub-accounts credited with Rollover Contributions. Withdrawal of Legacy After-Tax Contributions

Prior to Sept. 1, 1983, participant contributions to the Plan were made on an after tax basis. While you are an employee, you may withdraw all or any part of your Plan account’s Regular and Voluntary Contributions made before Sept. 1, 1983. The amount available will be adjusted to account for any net losses. You may not withdraw earnings attributable to these Regular and Voluntary Contributions. No Withdrawals from Certain Accounts

While you are an employee, you cannot, under any circumstances, withdraw from amounts attributable to your McKesson Matching Contributions, Non-Matching Employer Contributions, Additional ESOP Matching Contributions, RSP Contributions, PAYSOP Contributions, or the Special 1994 Allocation. Withdrawal of Amounts Under Predecessor Employers Plans

Certain participants who had accounts in plans of predecessor employers which were merged into the Plan may have special protected withdrawal rights with respect to the portion of their Plan accounts attributable to their interests in the prior plan.

17 Distributions Following Employment

Distributions Following Employment

A distribution of the vested portion of your Plan account is payable if you terminate employment for any reason. Your Plan benefits must begin to be paid to you as required minimum distributions no later than April 1 following the later of (1) the calendar year in which you reach age 72 (age 70½ if you attained that age on or before Dec. 31, 2019), or (2) the calendar year in which you retire from McKesson. Distribution Upon Death

If you die before all of your Plan benefits have been distributed, any remaining Plan benefits will be paid in a lump sum to your beneficiary as soon as practicable following the date of your death but in no event later than Dec. 31st of the calendar year that contains the fifth anniversary of your death. If you were married and your beneficiary designation does not provide for payment of death benefits to your spouse, that designation will be effective only if it includes the written and notarized consent of your spouse.

18 Payment Options and How to Request a Distribution

Payment Options

If your account balance is $1,000 or less, your account will be automatically paid out in a lump sum. If your balance is more than $1,000, you may elect to have your Plan benefit distributed in one of the following ways:

• paid as a lump sum in cash and, to the extent your account is invested in McKesson stock, in McKesson stock; or

• paid in partial withdrawals in cash and, to the extent invested in McKesson stock, in McKesson stock; or

• paid in whole or in part in cash in monthly, quarterly, semi-annual or annual installments of an approximately fixed or a variable value over a period of time not to exceed your remaining lifetime or the joint remaining lifetime of you and your spouse.

Partial withdrawals are subject to a $500 minimum. You may change an installment payment election only once in any Plan Year. Any election to change the period over which installment payments are to be made is void if the elected revised payment period exceeds the maximum payment period you could have designated at the time installment payments began. If you elect installments, no portion of your account balance can be distributed in McKesson stock. How to Request a Distribution

To request a distribution, withdrawal or rollover to another plan or IRA, log on to www.netbenefits.com or call 888.625.7747. You must call the McKesson Service Center to request a distribution in installments, in a lump sum, in partial withdrawals or as a required minimum distribution, or if you want to roll over all or a portion of the distribution to another eligible retirement plan, such as a new employer’s 401(k) plan or to an IRA.

19 Tax Consequences of Plan Payments

Tax Consequences of Plan Payments Rollovers and Direct Rollovers

The Plan is intended to meet the qualification requirements of Subject to the special rules applicable to Roth Deferrals Sections 401(a) and 401(k) and related provisions of the Internal described below, you may elect to roll over all or any portion Revenue Code (the “Code”). As long as the Plan remains so of an eligible payment from the Plan to an IRA, a Roth IRA, a qualified, the federal tax consequences of payments from 403(b) plan, a governmental 457 plan or to a tax-qualified plan the Plan will be as generally described below, subject to any described in Section 401(a) of the Code of another employer changes in applicable federal tax laws and regulations. such as a 401(k) plan that accepts rollovers (each, an “eligible retirement plan”). Hardship distributions, installments paid All payments to you from the Plan are subject to federal over 10 years or more, required minimum distributions and income tax unless they (1) are properly rolled over to an IRA or certain other payments are not eligible for roll over. The to another plan as described below, or (2) represent amounts amount rolled over will not be subject to income tax until it on which you already paid federal income tax such as Roth is distributed from the eligible retirement plan. But the 20% Deferrals, Roth converted amounts, After-Tax Contributions withholding tax will still apply, unless you arrange a direct and pre Sept. 1983 Regular and Voluntary Contributions. rollover as discussed below. Earnings on Roth Deferrals and Roth converted amounts are exempt from federal income tax if paid in a Roth distribution For example, assume that you are about to receive a taxable that is qualified. Under a special tax rule, while you are distribution of $10,000. If you do not arrange for a direct employed by McKesson, you may withdraw pre Sept. 1983 rollover, McKesson must withhold $2,000. As a result, you Regular or Voluntary contributions on a tax-free basis; earnings will have to contribute $2,000 from other sources in order to on such contributions are taxed when paid after you are no make a rollover of the full $10,000. Otherwise, you can only longer a McKesson employee. roll over $8,000, which means that you will owe tax on the $2,000. To the extent that the amount withheld is greater than Prior to receiving a payment from the Plan, you have the right the tax actually owed on the distribution (for instance because to receive a detailed explanation of the federal income tax a rollover was made), the amount withheld may be applied consequences of the payment. This explanation is posted at to other income tax liabilities or will be refunded by the IRS. www.netbenefits.com. For additional information about these However, the Plan is not required to withhold any amount from tax rules that apply to Plan payments, refer to IRS Publication the portion of a distribution that is made in McKesson stock. 575 “Pension and Annuity Income,” which is available from a local IRS office, on the internet at www.irs.gov or by calling You must make a rollover within 60 days after receipt of a 1-800-TAX-FORM. distribution. Shares of McKesson stock may be rolled over in kind. Alternatively, the shares may be sold, and the proceeds Mandatory Income Tax Withholding rolled over, in which event no gain or loss is recognized on the sale. If you make a rollover but choose to retain a part of the The taxable part of any payment that is an eligible rollover distribution that would have been eligible for inclusion in the distribution is subject to 20% income tax withholding. If the rollover, then that part is taxed entirely as ordinary income. payment includes McKesson stock, the amount withheld will not exceed the amount payable in cash. In a direct rollover, all or part of a Plan payment is paid directly from the Plan to an eligible retirement plan. (The plans of Certain states also may require additional mandatory other employers are not required to accept rollovers.) You must withholding. The amount withheld is applied to your income provide McKesson with the information that it needs to arrange tax liability for the year of the payment, like income taxes the direct rollover and comply with the other procedures withheld from salary. The fact that you may make a regular adopted by McKesson. A direct rollover is the only way to avoid rollover later has no bearing on mandatory withholding. 20% income tax withholding on any taxable payment from Rollovers and direct rollovers are discussed below. the Plan.

The portion of your account attributable to Roth Deferrals can only be directly rolled over to a Roth IRA or to another employer’s tax-qualified plan such as a 401(k) plan that provides for Roth elective deferrals.

In general, the tax treatment and rollover rules described above that apply to payments made to you as an employee also apply to payments to your surviving spouse upon your death or to 20 your spouse or former spouse who is an “alternate payee” under a qualified domestic relations order. Tax Consequences of Plan Payments

A distribution made to a beneficiary other than your surviving Roth Conversions or alternate payee spouse may also be rolled over, subject to the following rules: the non-spouse beneficiary must make The Plan gives you (or your surviving spouse beneficiary or a direct rollover of death benefits received from the Plan to alternate payee who is a spouse or former spouse) the flexibility an IRA or Roth IRA established to receive the distribution. to convert certain Plan sub-accounts (including your Pre-Tax Rollovers to another employer plan are not permitted. Also, Deferrals, Pre-Tax Employee Catch-Up Contribution, Matching the non-spouse beneficiary cannot receive a payment and then Contribution and After-Tax Contribution sub-accounts) into roll over the payment him/herself to the IRA. The IRA will be after-tax Roth accounts. Converted balances are credited to treated as an inherited IRA and will be subject to the required a Roth In-Plan Conversion sub account. Roth conversions minimum distribution rules that apply to beneficiaries under once made are irreversible. Loan balances, unvested amounts the Plan and to inherited IRA beneficiaries. Your non-spouse and special types of contribution sources are not eligible for beneficiary should consult with a personal tax adviser in order Roth conversion. to understand these rules before electing a rollover. Converted amounts will continue to be subject to the same Net Unrealized Appreciation distribution restrictions that applied prior to conversion, if any. Converted balances are subject to federal income tax Special tax treatment is available to lump-sum distributions in the year of conversion unless they represent amounts of company stock from 401(k) Plans. Upon the lump-sum on which you already paid federal income tax. If converted distribution of McKesson stock from the Plan, you are taxed on amounts include McKesson stock, the amount subject to the Plan’s tax basis in the stock as ordinary income. You have tax is based on the fair market value of the stock at the time no immediate tax liability for the net unrealized appreciation, of conversion. The favorable tax treatment afforded to net which is that portion of the distribution which represents the unrealized appreciation of McKesson stock described above difference between (1) the fair market value of the McKesson may be lost if McKesson stock is included in the conversion. stock at the time it is distributed to you; and (2) the value of the Because a conversion will trigger taxable income, you may stock at the time it was contributed to or otherwise acquired need to increase tax withholding from other sources or make by the Plan (the tax-paid 'basis'). When you eventually sell estimated tax payments to avoid tax underpayment penalties. McKesson stock outside of the Plan, the amount of the net A converted amount is not subject to the 10% excise tax on unrealized appreciation is taxed at the long-term capital gains early distributions unless it is distributed within five years of rate. Any additional appreciation from the date of distribution conversion. If you have multiple Roth conversions, a separate from the Plan until the date you sell the stock will be taxed at five year period is tracked for each conversion. If the conversion the long-term or short-term capital gains rate, depending on amount is distributed within the five-year period, the 10% tax how long you held the stock. Generally, a capital asset must applies to the distribution as if it were taxable to you unless you be held for a certain period, typically a year or more, before are exempt from the tax at the time of distribution. obtaining the more favorable tax treatment accorded to long- term capital gains; assets held for less than the required period Amounts distributed from a Roth In-Plan Conversion are taxed as short-term capital gains. sub-account are exempt from federal income tax if paid in a Roth distribution that is qualified as described on p. 8. For State Taxes purposes of determining whether the distribution is Roth qualified, the 5-year period starts on Jan. 1 of the first year that The state tax rules applicable to qualified plan distributions you either make a Roth Deferral or complete a Roth conversion vary from state to state. Accordingly, a participant should under the Plan. consult his or her own personal tax adviser concerning the state tax consequences of a qualified plan distribution. Tax Advice and Changes in Tax Laws

Excise Tax on Early Distributions or You are encouraged to consult a professional tax advisor before Withdrawals receiving a payment from the Plan and before electing a Roth conversion. The foregoing summary does not describe all of A 10% additional income tax will apply to the taxable amount the complex tax rules that apply. Also, Congress may amend of payments made before age 59½ (including a distribution the Code at any time and the IRS may issue new regulations or of earnings on Roth Deferrals that is not qualified). Certain rulings. Such developments could render all or any part of the withdrawals or distributions, however, are exempt from the foregoing tax summary discussion obsolete. McKesson assumes additional tax. Accordingly, a participant should consult his no responsibility for the continuing accuracy of the information or her own qualified personal tax adviser concerning the 10% provided above. additional income tax on qualified plan distributions.

21 Additional Information

Following is more important information that you should know The Senior Vice President will issue his written decision within about the Plan. 60 days after receipt of the appeal, unless special circumstances require an extension of time for processing, in which case the Filing a Claim written decision shall be issued as soon as possible, but not later than 120 days after receipt of an appeal. If such an extension If you or your beneficiary believe you are entitled to a benefit is required, written notice shall be furnished to you within the from the Plan which you have not yet received, you may file a initial 60-day period. This notice will state the circumstances claim by writing to the Senior Vice President, Total Rewards, requiring the extension and the date by which the Senior Vice McKesson Corporation, 6555 State Hwy 161, Irving, Texas President expects to reach a decision on your appeal. 75039. You will receive written notice of the decision on your claim within 90 days of filing your request, unless special If the decision on the appeal denies the claim in whole or in circumstances require an extension of up to an additional part, you will be provided with a written notice. The notice shall 90 days. state the reason(s) for the denial, including references to specific Appealing a Claim Denial Plan provisions upon which the denial was based. The notice will state that you and/or your authorized representative are If your claim is denied in whole or in part, you will receive entitled to receive, upon request and free of charge, reasonable notice stating the reasons for the denial and specific Plan access to, and copies of, all documents, records, and other provisions upon which the denial is based, and an explanation information relevant to the claim for benefits, and will describe of the Plan’s appeal procedures and the time limits applicable any voluntary appeal procedures, if any, offered by the Plan and to such procedures, including a statement of your right to bring your right to obtain the information about such procedures. a civil action under section 502(a) of the Employee Retirement The notice will also include a statement of your right to bring a Income Security Act of 1974 (“ERISA”) if your appeal is denied. legal action under Section 502(a) of ERISA after exhausting the If your claim is denied because you did not furnish complete claims procedure. information or documentation, the notice will also describe any If you do not file a claim, follow the claims procedures, additional information or material required to support your or appeal on time, you will give up legal rights, including claim and an explanation of why such information is required. your right to file a suit in federal court, as you will not have You may then appeal the decision by filing a written notice of exhausted your internal administrative appeal rights. Generally, appeal with the Senior Vice President, Total Rewards, McKesson you must exhaust your internal administrative appeal rights Corporation, 6555 State Hwy 161, Irving, Texas 75039, within before you can bring a suit in federal court. 60 days after receipt of the notice of denial. The Senior Vice No legal action may be commenced or maintained against the President, if good cause is shown, may extend the period during Plan, McKesson or the Plan Administrator more than one year which the appeal may be filed for another 60 days. You and/or after your appeal is denied. your authorized representative would be permitted to submit written comments, documents, records and other information relating to the claim for benefits. Upon request and free of charge, you and/or your authorized representative may also receive reasonable access to, and copies of, all documents, records or other information relevant to your claim.

The Senior Vice President’s review shall take into account all comments, documents, records and other information submitted by the appellant relating to the claim, without regard to whether such information was submitted or considered in the initial benefit determination, and shall not be restricted to those provisions of the Plan cited in the original denial of the claim.

22 Additional Information

Losing Your Benefits Assignment or Pledge of Interest

You may lose benefits under certain circumstances including: Except pursuant to a qualified domestic relations order, your interest in the Plan, whether before or after you retire, may not • You may lose your benefits if you cannot be located when be assigned or hypothecated by you or your beneficiary. benefits become payable to you. Therefore, it is very important that you keep Fidelity apprised of your mailing No Employment Contract address even after you have terminated employment. (The amount forfeited, unadjusted for gain or loss, will be Nothing in the Plan or the Plan description confers any right restored if you later make a claim for your benefit before of continued employment on any employee or in any way the Plan is terminated.) prohibits changes in the terms of, or the termination of, employment of any employee covered by the Plan. • Termination of employment before completing vesting requirements (to the extent such vesting requirements are No Pension Insurance applicable to your McKesson contribution sub-accounts). The Plan is subject to the principal provisions of Titles I and • A loss in value of your investments due to a drop in the II ERISA. The Plan is not subject to the provisions of Title value of any security or market fluctuations. IV of ERISA, which relates to plan termination insurance to be provided by the Pension Benefit Guaranty Corporation, • Your benefit may be reduced by account maintenance and a government corporation. Protections under Title IV are investment fees. applicable to defined benefit plans only, whereas the Plan is a defined contribution plan. • Your benefit may be reduced by amounts that you are ordered or required to pay under a qualified domestic relations order. The Plan’s procedures for determining whether a domestic relations order is a qualified domestic relations order are available, without charge, from the Plan Administrator.

• Your benefits may be reduced by amounts that you are ordered or required to pay the Plan, where such order or requirement: (1) arises under a judgment of conviction for a crime involving the Plan or a civil judgment (including a consent order or decree) entered by a court in an action brought in connection with a violation of part 4 of subtitle B of Title I of ERISA; and (2) the judgment, order, decree or settlement provides for the offset of all or part of the amount ordered or required to be paid to the Plan against the benefits provided under the Plan.

23 Additional Information

Termination, Amendment and Suspension Maintenance of Plan Records

McKesson intends to continue the Plan indefinitely, but Fidelity maintains the records relating to the Plan. A report McKesson reserves the right to amend, suspend or terminate summarizing the status of a participant’s account is available the Plan at any time and for any reason by resolution of its CEO. by logging onto www.netbenefits.com. Copies of the Plan The Senior Vice President — Total Rewards may amend the document can be requested by calling 888.625.7747. Plan as may be necessary to comply with applicable law and that does not materially increase the costs of the Plan. No such Account Maintenance Fees amendment, suspension or termination shall be made so as to Each Plan participant is charged a fixed per participant account permit any part of the Trust to be used for any purpose except maintenance fee that will be the same regardless of contribution for the exclusive benefit of participants and their beneficiaries level or account balance. This fee is $9.50 per quarter ($38.00 nor to affect adversely any right the participant or his or her per year) and is automatically deducted from accounts. The fee beneficiary may then have with respect to contributions is subject to change. previously made except as may be necessary to obtain or retain qualification of the Plan and the Trust under the Code.

The Plan is designed to qualify under Sections 401(a), 401(k), 409 and 4975(e) of the Internal Revenue Code. If it is ever finally determined that the Plan as adopted by any employer no longer satisfies these sections, such employer and its employees shall cease to participate in the Plan at the date of such determination.

In the event that the Plan is terminated or partially terminated, or if the contributions of any Plan Employer are completely discontinued, the amounts credited to the accounts of all affected employees shall be vested and non-forfeitable. McKesson shall determine the time and method of payment of such amounts on a uniform and nondiscriminatory basis. The Trust shall continue until, at the direction of McKesson, the entire value of the account of each participant has been distributed to or applied for the benefit of each participant or his or her beneficiary. Special Plan Provisions and Inactive Accounts

The Plan contains several provisions that are not currently in effect, including Additional ESOP Matching Contributions, RSP Contributions, Non-Matching Employer Contributions, special provisions relating to the PCS Transaction, the special 1994 Allocation, PAYSOP contributions and Quarterly Contributions. Information about these obsolete provisions may be obtained from McKesson.

24 Plan Administration Information

Plan Administration Information McKesson maintains accounts for each participant under the Plan. McKesson is required to provide to each a participant McKesson has full discretionary authority to administer the a quarterly statement with respect to the status of his or her Plan and to interpret its provisions. McKesson will make such account, setting forth the value of his or her account as of the rules, regulations, computations, interpretations and decisions end of the calendar quarter and the preceding calendar quarter, as necessary to administer the Plan in a nondiscriminatory the amount of Elective Deferrals (including Pre-Tax, Roth and manner for the exclusive benefit of the participants and their Catch-Up Contributions), After-Tax Contributions and Matching beneficiaries. The conclusions and decisions of McKesson on all Contributions, and any withdrawals made by the participant such matters shall be final as to all interested parties. No person during the calendar quarter. is entitled to benefits unless McKesson determines they are entitled to them.

McKesson has appointed Fidelity Management Trust Company as Trustee under the Plan. As frequently as weekly, McKesson turns over to the Trustee, and the Trustee has custody of, the contributions made on behalf of each participant. The Trustee is responsible for the administration of these contributions in accordance with the provisions of the Plan. From time to time, the Board of Directors of McKesson may appoint independent investment advisers to invest the Core Options under the Plan. McKesson may from time to time give the Trustee such instructions and directions as may be necessary to administer the trust and to carry out the provisions of the Plan. Except for investment management fees for the participant-directed investment options, which are paid from the Plan Trust, McKesson has complete and unfettered discretion to determine whether an expense of the Plan is paid by McKesson or the Plan Trust.

If shares of McKesson Stock must be acquired by the Trust, the Trustee may purchase them at the prevailing market price established on the New York Stock Exchange or otherwise in the open market. Shares may be purchased on the open market or from McKesson. In addition, McKesson may contribute shares of McKesson Stock to the Plan from authorized, but unissued shares, or out of its treasury shares.

25 Your Rights as a Plan Participant

As a participant in the Plan, you are entitled to certain rights Enforcing Your Rights and protections under Title I of the Employee Retirement Income Security Act of 1974 (ERISA). Under ERISA, you can take steps to enforce these benefits rights. For instance, if you request materials from the Plan Right to Information Administrator and do not receive them within 30 days, you may file suit in federal court after having exhausted the You may examine without charge all official Plan documents internal claims procedure. The court may require the Plan during business hours in the McKesson Benefits Department. Administrator to provide the materials and pay up to $110 a day These documents include the legal texts of the Plan, insurance until you receive them, unless the materials could not be sent contracts, trust agreements, summary plan descriptions and because of reasons beyond the Administrator’s control. annual reports that McKesson files with the U.S. Department of Labor. If your claim for benefits is denied or ignored in whole or in part and if you have exhausted the Plan’s claims procedure, You may also obtain a copy of any of these documents by you may file suit in a state or federal court. In addition, if you writing to the Plan Administrator. You may be charged a disagree with the Plan’s decision or lack thereof concerning the reasonable fee for copies. qualified status of a domestic relations order, you may file suit You have the right to receive a summary of the Plan’s annual in federal court. financial report. The Plan Administrator is required by law If the Plan’s fiduciaries misuse the Plan’s money, or if you are to furnish each participant with a copy of this summary discriminated against for asserting your rights, you may seek annual report. assistance from the U.S. Department of Labor, or file suit in a In addition to certain rights for Plan participants, ERISA federal court. The court decides who should pay court costs and imposes duties on people responsible for the operation of the legal fees. If you are successful, the court may order the person Plan. These people, called fiduciaries, have a duty to operate you sued to pay these costs and fees. If you lose, the court may the Plan prudently and in the interest of all Plan participants order you to pay these costs and fees — for example, if it finds and beneficiaries. your claim is frivolous.

No one, including your employer, your union or any other Questions person, may fire you or otherwise discriminate against you in If you have questions about the Plan, log on to any way for obtaining benefits or exercising your ERISA rights. www.netbenefits.com, call 888.625.7747 or contact the Plan Denied Claim Administrator. If you have any questions about this statement or about your rights under ERISA, or if you need assistance in If your claim for a benefit under the Plan is denied in whole or obtaining documents from the Plan Administrator, you should in part, you must receive a written explanation of the reason for contact the nearest office of the Employee Benefits Security denial, have the right to obtain copies of documents relating to Administration, U.S. Department of Labor, listed in your the decision without charge, and have the right to appeal the telephone directory, or the Division of Technical Assistance denial, all within certain time schedules. and Inquiries, Employee Benefits Security Administration, U.S. Department of Labor, 200 Constitution Avenue N.W., Washington, D.C. 20210. You may also obtain certain publications about your rights and responsibilities under ERISA by calling the publications hotline of the Employee Benefits Security Administration.

26 Administrative Facts

Name of Plan Termination Fidelity Management & Research If the Plan is terminated in whole Company McKesson Corporation 401(k) Retirement or in part, the rights of all affected 82 Devonshire St. Savings Plan participants to their accounts as of the Boston, MA 02109 date of termination will be 100% vested Type of Plan and non-forfeitable. Fisher Investments Defined Contribution Plan; ERISA § 13100 Skyline Boulevard 404(c) Plan Service of Process Woodside, CA 94062 The Plan’s agent for service of legal Plan Number process is McKesson’s Corporate J.P. Morgan Asset Management 002 Secretary at the following address: 270 Park Ave New York, NY 10017 Employer Identification Number Office of the Corporate Secretary 94-3207296 McKesson Corporation Loomis Sayles One Financial Center Plan Sponsor 6555 State Hwy 161 Boston, MA 02111 McKesson Corporation Irving, Texas 75039 6555 State Hwy 161 Legal process may also be served on the Manulife Irving, Texas 75039 Plan Administrator. 197 Clarendon St. Boston, MA 02116 Plan Administrator Investment Managers McKesson Corporation Nationwide International Small Cap c/o Senior Vice President, Total Rewards BlackRock Institutional Trust One Nationwide Plaza 6555 State Hwy 161 Company, N.A. Columbus OH 43215 Irving, Texas 75039 400 Howard Street Telephone: (972) 446-4800 San Francisco, CA 94105 Standish Mellon Asset Management Attention: Legal Department Company LLC Plan Trustee or by facsimile to (415) 618-1383 100 Pine Street, 32nd Floor Fidelity Management Trust Co. San Francisco, CA 94111 245 Summer Street Brown Advisory Boston, MA 02110 901 South Bond Street State Street Global Advisors One Lincoln Street Type of Administration Suite 400 Baltimore, MD 21231 State Street Financial Center Boston, MA 02111-2900 The Plan is administered by the sponsor. Dodge & Cox Certain administrative functions are 555 California Street, 40th Floor The Vanguard Group, Inc. outsourced to: San Francisco, CA 94104 P.O. Box 2900 Valley Forge, PA 19482-2900 Fidelity Investments Institutional Eaton Vance Management Operations Company, Inc. Two International Place, 10th Floor Weatherbie Capital, LLC 82 Devonshire St. Boston, MA 02110 265 Franklin Street Boston, MA 02109 Boston, MA 02110

Funding Medium Voya 230 Park Avenue The Plan is funded by employee and New York, NY 10169 McKesson contributions. Benefits are paid from a Trust fund.

Plan Year April 1 – March 31

27 Important Contact Information

UPoint digital.alight.com/mckesson The benefits described in this booklet are available to eligible employees of McKesson Corporation. While the Your online source for benefits information. 401(k) plan is expected to continue, McKesson reserves the right to amend, suspend, or terminate the plan at any time. The plan’s terms cannot be modified by written or oral HR Support Center statements to you from Human Resources representatives 855.GO.MCKHR (855.466.2547) or other personnel. If there is a conflict between this summary and the terms of the plan, the terms as set forth Your source for benefits information in the 401(k) plan document govern. and gateway to an advocate. Press 2 for Leave of Absence questions. Benefit experts are available 8 am - 7 pm ET, M-F. Oprime 2 para asistencia en español.

UPoint digital.alight.com/mckesson Your online source for benefits information.

McKesson 401(k) Plan SPD 8-27-2021