Leidos, Inc.RetirementPlan SummaryPlanDescription January ......Leidos, Inc.RetirementPlan SummaryPlanDescription January 1, 2018 Updated for the following: Beneficiary Information

Leidos, Inc. Retirement Plan Summary Plan Description JANUARY 1, 2021

This summary applies to non-bargained and bargained employees eligible to participate in the Plan. A copy of this summary can be found on the Leidos Retirement Plan page on Prism. Bargained Employees: refer to your applicable Collective Bargaining Agreement with Leidos in conjunction with this summary for the terms applicable to you.

Prospectus Information

This document constitutes part of a prospectus covering securities that have been registered under the Securities Act of 1933, as amended. Please consult the Supplement to Prospectus and Summary Plan Description for information regarding Company Stock. The prospectus for the Leidos, Inc. Retirement Plan (including the Company’s filings with, and disclosures to, the Securities and Exchange Commission) specifically are not incorporated into and are not part of this Summary Plan Description. The date of this document is January 1, 2021. When the term “Company” is used in this summary, it may also mean any affiliated companies, the parent company or any successor (and prior to September 2013, to Science Applications International Corporation). Service with any participating company may determine eligibility to participate, vesting credit and allocation of contributions to the Leidos, Inc. Retirement Plan (herein referred to as “Plan”). Summary Disclaimer

This summary does not contain all the details of the Plan or determine your rights under the Plan, but is intended only to answer the most frequently asked questions about the Plan and to provide a description of the material terms of the Plan and how the Plan operates. The official Plan document sets forth your rights and obligations under the Plan. If there is a conflict between the Plan document and this summary, the terms of the Plan document will control. Nothing in this summary should be considered as altering or affecting the provisions of the Plan document itself. In determining specific benefits, the full Plan provisions, as they exist now or in the future, always govern. Also, the Plan may be amended without prior notice, and this summary may not be updated until a date later than the effective date of a Plan amendment. Copies of the Plan document are available for your review upon your request.

Leidos, Inc. Retirement Plan Saving for retirement is one of the best ways to help ensure that you will be financially secure when you are no longer working. The Plan is one of the ways you have to build your retirement savings.

A Brief Overview Here are some of the Plan’s highlights:

• It’s easy to save for retirement. You save money each pay period with deductions taken

directly from your paycheck.

• It’s flexible. You can change or stop contributions or change your investment options at any time. You have easy access to your Plan information online day or night or through a toll-free telephone number where dedicated specialists can assist you weekdays, 8:30 a.m. – 9 p.m., ET.

• You can make Pre-Tax Contributions, which lower your current taxable income. You don’t pay income taxes on your savings or their earnings until they are distributed, usually at retirement.

• You can make Roth 401(k) Contributions, which allow you to contribute after-tax dollars to the Plan and withdraw these amounts during your retirement without paying additional taxes. In addition, the earnings on these contributions are tax-free if you hold the Roth 401(k) account for at least five years and are at least age 59½ on the date of distribution. Note: Puerto Rico Participants are not eligible to make Roth contributions.

• You can make Traditional After-Tax Contributions, which allow you to contribute after-tax dollars to the Plan and withdraw them at any time. Earnings on after-tax contributions are not taxed until they are distributed. Traditional After-Tax Contributions are not eligible for Company match.

• Bargained Employees may make an additional CODA Deferral, on a pre-tax basis if your collective bargaining agreement with Leidos provides for a CODA Deferral.

• The Company contributes. Leidos adds to your savings by making Company Matching Contributions each pay period based on your Pre-Tax and Roth 401(k) Contributions as long as you make a contribution each pay period and you are in an eligible fringe benefit package. Bargained Employees: refer to your applicable collective bargaining agreement with Leidos for terms applicable to you.

• Catch-Up Contributions happen automatically. If you are or will be age 50 during the plan year, your Pre-Tax and Roth 401(k) Contributions can continue beyond the IRS limit to include the allowed Catch-Up Contribution. Just make sure to adjust your deferral percentage to reach the total amount you wish, up to the limit.

• You are in control. You choose how contributions are invested from a variety of

diversified investment options.

• You have access to loans. While you are employed by Leidos, you may elect to take a loan from the Plan. Even after your employment ends, if you maintain a balance in your 401(k) account, you may still have access to loans.

• The benefit is yours. Your vested Plan benefits are payable upon your termination, disability or death, and in some cases while you are still working. In most cases, you can elect to receive your benefits as a lump-sum cash payment or installment payments, or you may roll over your balance to the qualified plan of another employer, or to a Rollover IRA. In some cases, the amounts you have invested in Company Stock may be paid to you in kind as shares of Leidos, Inc. common stock.

The chart below provides a summary of the important features of the Plan: Employee Contributions You can save up to 90% of your eligible compensation

into the Plan, subject to the IRS limits. You can make your contributions on a Pre-Tax basis, Roth basis, or After-Tax basis. Please note Puerto Rico Participants are not eligible to make Roth contributions and are subject to a 10% cap on After-tax contributions.

CODA Deferrals Bargained Employees: If your collective bargaining agreement with Leidos provides for a special “CODA” amount equal to a percentage of your regular compensation, you can elect to defer up to 100% of this amount in the Plan, in addition to your other Contributions.

Company Contributions For eligible fringe groups, the Company also provides a matching contribution based on your Pre-Tax and Roth 401(k) Contributions to supplement the amount you save for retirement. Company Contributions are posted to your account each pay period in which you make Pre-Tax and/or Roth 401(k) Contributions and are applied to the same investment elections as your Employee Contributions. Bargained Employees: refer to your collective bargaining agreement with Leidos for terms applicable to you.

Vesting

You are always 100% vested in your contributions into the Plan. If you work on or after January 1, 2018, full Vesting occurs after three Years of Service: the Company Matching Contributions vests 25%

after completing your first Year of Service, 50% after your second Year of Service, and you are 100% vested after completing your third Year of Service.

Vesting, continued If you did not work on or after January 1, 2018, a different Vesting schedule applies to your Company Matching Contributions. Please refer to the Summary Plan Description in place at the time of your separation for details.

Investments The Plan offers a diversified selection of investment options for you to elect how to invest your Plan account. The Plan also allows you to invest in a Company Stock fund.

Loans You can have up to two outstanding loans from the Plan – either two general purpose loans, or one general purpose loan and one loan used for the purchase of your principal residence.

Withdrawals You can withdraw your Traditional After-Tax Contributions and Rollover amounts from the Plan at any time. You can withdraw amounts for a hardship. You can withdraw amounts for any reason if you are age 59½ or older. You can withdraw limited amounts for expense related to the birth or adoption of a child. When you leave the Company, you can leave your account with the Plan, or you can receive a distribution of your account as a lump sum, partial lump sum or installment payments. If you take your money from the Plan before age 59½, you may be subject to an additional tax of 10% on pre-tax amounts (and a 10% penalty on the portion of the withdrawal that represents Roth earnings). You will also owe taxes on any earnings for pre-tax and traditional after-tax lump sum or partial lump sum withdrawals. If you separate from service at age 55 or older, or elect at any age to receive substantially equal installment payments to be made annually over your life expectancy, you may have exceptions to the 10% early withdrawal penalty.

Contents Glossary 1 Eligibility and Participation 4 Who Is Eligible 4 Who Is Not Eligible 4 When You May Begin to Participate 4 How to Enroll 4 Contributions to the Plan 5 Your Contributions 5 Rollovers Contributions 11 In-Plan Roth Conversion 12 Company Contributions 13 How Contributions Are Invested 14 Leidos Stock Funds 15 Valuation of Leidos Stock Fund Accounts 16 Keeping Track of Your Account 16 How Vesting Works 17 Vesting of Your Contributions 17 Vesting of Company Contributions 17 How Service is Counted 18 What Is an Hour of Service? 18 What Is a Year of Service? 18 What is a Break in Service? 19 Taking a Loan from Your Account 20 How Much You May Borrow 20 Repaying Your Loan 20 Withdrawals 21 Withdrawals While You Are Actively Employed 21 Withdrawals When You Are No Longer Actively Employed 23 Beneficiary Information 26 Learning More About the Plan 29 Online Access 29 Telephone Access 29 Other Information You Should Know 29 Employment Transfers 29 Loss or Denial of Benefits 30 Claim Procedures 32 Fees and Expenses 33 Plan Administration 34 ERISA Rights 35 Plan Information 37 Additional Information Supplement to Prospectus and Summary Plan Description 39 Your Investment Options at a Glance 47

Leidos, Inc. Retirement Plan Summary Plan Description | 1

Glossary There are various terms used in this summary that have a specific meaning with respect to the Plan. This section explains those terms so that you can better understand your benefits. These terms are printed in boldface whenever they appear to let you know that they are defined here. Bargained Employees Bargained Employees means an employee of the Company covered by a collective bargaining agreement between the Company and “employee representatives” under which retirement benefits were the subject of good faith bargaining. Beneficiary The person or persons designated to receive your account in the event of your death. If you do not have a Beneficiary on file with Vanguard at the time of your death, your Plan assets will be distributed to your spouse if you are married, or to your estate if you are not married. Beneficiaries you elect may be either an “Eligible Designated Beneficiary” or “Non-Eligible Designated Beneficiary” as defined by the IRS and this may impact the manner and timing in which they may elect to distribute the account.

Break-in-Service Any 12-month Computation Period during which you have 425 or fewer Hours of Service. Catch-Up Contribution Contributions you may make if you will be at least age 50 before the last day of the calendar year and have exceeded your regular 401(k) elective contribution limits. If you are eligible to make Catch-Up Contributions (maximum $6,500 or $1,500 for Puerto Rico Participants in 2021), and the sum of your Pre-Tax Contributions and Roth 401(k) Contributions for the year have reached the IRS contribution limit ($19,500 in 2021), any further contributions you make based on the percentage of pay you elect will automatically be considered Catch-Up Contributions. Catch-Up Contributions will be made based on your election of Pre-Tax Contributions and/or Roth 401(k) Contributions. Contribution limits and Catch-Up Contribution limits are established by the IRS and may be adjusted annually. CODA or CODA Deferrals An elective contribution made by you and deducted from a cash or deferred arrangement, or CODA, cash payment to you from the Company under a collective bargaining agreement with Leidos. Committee The Leidos, Inc. Retirement Plans Committee or any successor of that Committee. Company Leidos, Inc. (or its parent corporation), or any successor of Leidos. Company also includes any affiliated company (or other entity) that has been granted permission by the Board of Directors to participate in the Plan.


Company Matching Contribution A Company contribution made to your account as a result of your having made 401(k) elective contributions on either a Pre-Tax and/or Roth 401(k) After-Tax basis. Traditional After-Tax Contributions are not eligible for Company Matching Contributions. Company Stock Common stock of Leidos Holdings Inc. (the parent corporation of Leidos, Inc.) which is publicly traded on the New York Stock Exchange under the symbol “LDOS.” Computation Period A 12-month period of time used to determine your Years of Service for Vesting purposes and whether you have had a Break-in-Service. The Computation Period for Break-in-Service purposes is the 12 months following your hire date, and after that any calendar year starting after your hire date. For purposes of Vesting, the relevant Computation Period in all cases is the calendar year. ERISA The Employee Retirement Income Security Act of 1974, as amended from time to time. Hour of Service For an hourly employee, each hour of working or nonworking time (e.g., vacation, sick leave, jury duty) for which you are paid or entitled to be paid by the Company. Salaried employees are credited with 45 hours of service each week of service, regardless of actual number of hours worked. Plan Administrator The administrator of the Plan, in this case, the Company. Pre-Tax Contribution An elective contribution made by you and deducted from your paycheck before federal and state income taxes (unless required by your state) are withheld. You do not pay any income tax on these contributions and related earnings until distribution. Puerto Rico Participants Puerto Rico participants under the Plan are employees who are employed by the Company in Puerto Rico and are a bona-fide resident of Puerto Rico or perform labor or services primarily within Puerto Rico, regardless of residence. Rollover Contribution An employee’s voluntary contribution of amounts from the qualified retirement plan of a previous employer or an eligible Rollover IRA. Roth 401(k) Contribution An elective contribution made by you, designated as a Roth 401(k) Contribution, and deducted from your paycheck after federal and state income taxes are withheld. Provided certain criteria are met at the time you take a distribution of these contributions, you will not pay any income tax on these contributions and related earnings at distribution. Please note Puerto Rico Participants are not eligible to make Roth 401(k) Contributions.


Leidos Stock Funds The funds which invest primarily in Leidos, Inc. common stock and have a small cash position to facilitate transactions. There are two Leidos Stock Funds – the Leidos Common Stock Fund and the Leidos Closed Stock Fund. Traditional After-Tax Contribution A contribution made by you and deducted from your paycheck after federal and state income taxes are withheld, that is not a Roth 401(k) Contribution. Traditional After-Tax Contributions are not eligible for Matching Contributions. Vesting Your right to ownership in your Plan account. You are vested immediately upon eligibility for your own contributions. Company contributions are subject to a Vesting schedule based on Years of Service. You are 100% vested in dividends from Company Stock that are reinvested in the Plan. Year of Service A Computation Period (calendar year) during which you complete 850 or more Hours of Service. You will never receive more than one Year of Service with respect to services performed in a single Computation Period.


Eligibility and Participation Who Is Eligible You are eligible to participate in the Plan if you are an employee of Leidos or a participating employer, unless you fall into one of the categories described under “Who Is Not Eligible” below. Some Bargained Employees covered by a collective bargaining agreement with Leidos that provides for Plan coverage may participate in this Plan subject to the terms of the collective bargaining agreement. You must be in an eligible fringe benefit package to receive Company Matching Contributions. Bargained Employees: refer to your collective bargaining agreement with Leidos for terms applicable to you. Who Is Not Eligible The following groups of employees are not eligible to participate in the Plan:

• Those employed by a subsidiary of Leidos that is not a participating employer • Those considered part of an ineligible class or ineligible fringe benefit package • Leased employees • Nonresident alien employees with no income in the United States • Individuals not treated by the Company as employees on payroll for any given Plan year (for

example, consultants and independent contractors are not eligible) • Those covered by a collective bargaining agreement that doesn’t provide for Plan coverage • Joint venture employees

When You May Begin to Participate If you are eligible for the Plan, you may begin participating in the Plan immediately. If you are in an eligible fringe benefit package, you will be eligible to receive Company Matching Contributions on your Pre-Tax Contributions and/or Roth 401(k) Contributions. Bargained Employees: refer to your collective bargaining agreement for terms applicable to you.

Your Pre-Tax Contributions, Roth 401(k) Contributions, Traditional After-Tax Contributions, Catch-Up Contributions, and Company Matching Contributions are credited to your account as soon as administratively feasible after the contributions are made through payroll deductions. Rollover Contributions are credited to your account as soon as administratively feasible after being made to the Plan. How to Enroll To start making elective contributions or Rollover Contributions to the Plan, go to www.vanguard.com/retirementplans or call Vanguard at (800) 523-1188. To enroll, you will need the Record Keeper Plan number: 090518 for non-bargained employees or 094548 for bargained employees. Payroll deductions will begin as soon as administratively feasible after you enroll – approximately


one to two pay periods after Vanguard has received your election, and depending on payroll calendar timing. Bargained Employees: If you are eligible to receive a CODA, you must make a separate deferral election for the CODA. When you enroll, you should complete a Beneficiary election with Vanguard to indicate who will receive your account in the event of your death. If you do not have a Beneficiary on file with Vanguard at the time of your death, your Plan assets will be distributed to your spouse if you are married, or to your estate if you are not married. You can make or update your Beneficiary election online at www.vanguard.com/retirementplans or by calling Vanguard. You need to make a separate Beneficiary election with Vanguard for your Plan assets, as Beneficiary elections on file for other Leidos benefits do not apply to the Leidos, Inc. Retirement Plan.

Contributions to the Plan Your Plan account consists of contributions you make and contributions Leidos makes (if applicable), along with any associated investment earnings.

Contributions You Can Make Contributions Leidos Makes

401(k) elective contributions for either: • Pre-Tax Contributions • CODA Deferrals

(Bargained Employees only: if your collective bargaining agreement provides for CODA)

• Roth 401(k) Contributions Up to the IRS limit, including Catch-up contributions.

• Company Matching Contributions made on a per paycheck basis, based on your elective contributions, if you are in an eligible fringe benefit package (Bargained Employees: You receive a Company Match Contribution if it is provided for in your collective bargaining agreement. CODA Deferrals are not eligible for Company Matching Contributions.)

Traditional After-Tax Contributions • Not eligible for Company Matching Contributions

Rollover Contributions • Not eligible for Company Matching Contributions

Your Contributions Through your elective contributions, you may save as much or as little as you like — within Plan limits. You may make the following types of contributions to the Plan: • Pre-Tax Contributions — Pre-tax contributions of a percentage of your eligible

compensation, deducted from your pay each pay period.


• CODA Deferrals — Bargained Employees only: A separate Pre-Tax Contribution you elect to defer from a percentage of your eligible compensation you receive each pay period in cash, if your collective bargaining agreement with Leidos provides for a CODA Deferral.

• Roth 401(k) Contributions — After-tax contributions of a percentage of your eligible compensation, deducted from your pay each pay period, that are designated as Roth 401(k) Contributions. Please note Puerto Rico Participants are not eligible to make Roth contributions.

• Catch-Up Contributions — Pre-Tax Contributions or Roth 401(k) Contributions made by participants who will be at least age 50 in the calendar year and make contributions in excess of the $19,500 limit for 2021 (as adjusted annually by the IRS). Please note: Catch-Up Contributions are automatically deducted from your pay when you elect a deferral percentage that will result in you exceeding the IRS limit of $19,500 for 2021.

• Traditional After-Tax Contributions — After-tax contributions of a percentage of your eligible compensation, deducted from your pay each pay period

• Rollover Contributions — Assets you transfer from the qualified retirement plan of another employer or employers, or from an eligible rollover conduit Individual Retirement Account (IRA)

In addition, if you participated in the Plan before 1987, you may have made voluntary contributions on an after-tax basis. These contributions are held in a separate source within your Plan account.

The availability of the Plan may affect your ability to make deductible contributions to an IRA. Please consult your personal tax advisor for more detailed information.

Call Vanguard at (800) 523-1188 or visit www.vanguard.com/retirementplans (reference Record Keeper Plan number 090518 for non-bargained employees or 094548 for bargained employees) to:

• Start or stop contributing to the Plan • Change your contribution amount • Sign up for annual automatic increases of your contribution amount • Change your investment options for future contributions • Exchange between investment options • Change or designate a Beneficiary


401(k) Elective Contributions You can save for retirement with Pre-Tax Contributions or Roth 401(k) Contributions, or a combination of both. These contributions are deducted from your pay each pay period. If you will be at least age 50 at any time during the calendar year, you can also make additional Catch-Up Contributions during that year. Please note Puerto Rico Participants are not eligible to make Roth contributions.

Pre-Tax Contributions and Roth 401(k) Contributions are eligible for Company Matching Contributions if you are in an eligible fringe benefit package. Bargained Employees: refer to your collective bargaining agreement with Leidos for terms applicable to you. You can invest your contributions in any of the investment options provided by the Plan. Refer to “Your Investment Options at a Glance” for more information on the investment options provided by the Plan. Pre-Tax Contributions (including CODA Deferrals) When you save for retirement by making Pre-Tax Contributions (including CODA Deferrals) to the Plan, your contributions are deducted from your pay before federal and state income taxes are withheld. You do not pay income taxes on the amounts you contribute until you withdraw the money, usually at retirement. However, these contributions are subject to FICA taxes at the time of your contribution (i.e., Social Security and Medicare). When making Pre-Tax Contributions (including CODA), you get to invest money you would ordinarily pay in taxes. In addition, any earnings on your Pre-Tax Contributions (including CODA) grow on a tax-deferred basis, meaning that you do not pay income taxes on these contributions or their earnings until they are distributed. Roth 401(k) Contributions Unlike Pre-Tax Contributions, Roth 401(k) Contributions to the Plan are made with after-tax dollars and must be designated as Roth 401(k) Contributions. As a result, applicable federal, state, local, Social Security and Medicare taxes are withheld from your Roth 401(k) Contributions at the time of your contribution, and the amount of your contributions will be included in your current year taxable income. Roth 401(k) Contributions allow you to make after-tax contributions to the Plan and withdraw these amounts tax-free during your retirement. In addition, the earnings on these contributions are also tax-free if you have held the Roth 401(k) account for at least five years and are at least age 59½ on the date of distribution. For some employees, this can be an advantage over making Pre-Tax Contributions which, along with applicable earnings, are subject to federal and state income taxes at the time of distribution. Because taxes are withheld from Roth 401(k) Contributions and not from Pre-Tax Contributions, the type of contribution you choose will impact your take home pay and tax liability differently. Consult your tax advisor for assistance in determining what best meets your needs. Please note Puerto Rico Participants are not eligible to make Roth contributions.

Traditional After-Tax Contributions Traditional After-Tax Contributions to the Plan are made with after-tax dollars. As a result, applicable federal, state, local, Social Security and Medicare taxes are withheld from your


Traditional After-Tax Contributions at the time of your contribution, and the amount of your contributions will be included in your current year taxable income. Any earnings on your Traditional After-Tax Contributions grow on a tax-deferred basis, meaning that you do not pay income taxes on the earnings until they are distributed. This taxation is different than a qualifying distribution of earnings on Roth 401(k) Contributions. Take a look at this example of someone who earns $60,000 and contributes 6% to the Plan.

Pre-Tax Contributions Roth 401(k) Contributions

Traditional After-Tax Contributions

Annual eligible compensation

$60,000

$60,000

$60,000

Pre-Tax Contributions $3,600 $0 $0

Taxable income $56,400 $60,000 $60,000

Social Security + Medicare tax (7.65%)* $4,590 $4,590 $4,590

Federal + state income tax (at 33%)** $18,612 $19,800 $19,800

Roth or After-Tax Contributions $0 $3,600 $3,600

Annual take-home pay $33,198 $32,010 $32,010

Difference in take-home pay

$0 ( $1,188)

Taxation at Distribution Federal/State Income Tax on Contributions

and Earnings None Federal/State Income

Tax on Earnings

*Pre-tax contributions do not reduce your Social Security and Medicare Tax **Estimated federal and state withholding. Actual withholding may differ for each participant.

How Much You May Contribute You may elect to contribute up to 90% of your eligible compensation as Pre-Tax Contributions and/or Roth 401(k) Contributions (including Catch-Up Contributions), or as Traditional After-Tax Contributions. Puerto Rico Participants are not eligible to make Roth contributions and are subject to a 10% cap on After-Tax Contributions. Bargained Employees: CODA (if provided in your collective bargaining agreement with Leidos) is an additional amount you may contribute.

The sum of your Pre-Tax Contributions, Roth 401(k) Contributions, Catch-Up Contributions, and Traditional After-Tax Contributions for a payroll period cannot exceed 90%. Bargained Employees: If your collective bargaining agreement with Leidos allows for a CODA Deferral, you may contribute up to 100% of your CODA amount on a pre-tax basis to the Plan in addition to the 90% limitation described above. Your Pre-Tax Contributions, CODA Deferrals and Roth 401(k) Contributions are also subject to the following Internal Revenue Service (IRS) contribution limits:

You may contribute up to $19,500 in Pre-Tax Contributions, CODA Deferrals and Roth 401(k) Contributions for 2021 (adjusted annually by the IRS).

($1,188)


If you will be at least age 50 or older during the calendar year, you may make an additional

Catch-Up Contribution of up to $6,500 (or $1,500 for Puerto Rico Participants) in 2021 (adjusted annually by the IRS), for a total contribution of $26,000 (or $21,000 for Puerto Rico Participants) in 2021.

The IRS limits the total amount that can be contributed to your account on an annual basis. For 2021, the combined limit for all employee and employer contributions, including Pre-Tax, CODA Deferrals, Roth 401(k), Traditional After-Tax, and Company Matching Contributions, cannot exceed $58,000, plus Catch-Up Contributions.

For example: A 40-year-old Plan participant, earning $75,000 a year, makes $19,500 in pre-tax and/or Roth 401(k) Contributions in 2021. The Company contributes a match of $3,750. Because the IRS limit of $58,000 includes pre-tax, Roth 401(k), as well as employer contributions, the participant can still contribute up to $34,750 in Traditional After-Tax Contributions.

If your Pre-Tax Contributions, CODA Deferrals, and/or Roth 401(k) Contributions exceed the IRS limits because you contributed to more than one 401(k) or 403(b) plan during the year, you should consult your tax advisor for assistance. The Plan will not refund excess contributions except as specified below; alternatively, you may be able to request a refund from the other plan to which you contributed.

Excess Contributions If you contribute to multiple 401(k) plans in a particular Plan Year (e.g., because you begin or terminate employment with the Company in the middle of that Plan Year) and your contributions to the Plan and your other employer’s 401(k) plan exceed the limitations provided above, you may request a refund of excess contributions by contacting Vanguard in writing by April 1 of the following year. Please contact Vanguard at (800) 523-1188 for additional information on what you must submit to request a refund of your excess contributions. Upon receipt of a completed written notification, Vanguard will distribute your excess contributions requested (and any income applicable thereto) no later than April 15th of the calendar year in which you request such amounts. Matching contributions (plus related earnings) that correspond to the excess contributions will be immediately forfeited. Excess contributions will be adjusted for any income or loss up to the last day of the Plan Year in which such amounts were contributed. Excess contributions attributable to Roth 401(k) Contributions will be refunded before excess contributions attributable to Pre-Tax Contributions unless you elect otherwise.

As stated above, federal law limits the total amount of all contributions other than Catch-Up Contributions that can be made to the Plan. In 2021, the limit is $58,000 (plus Catch-Up Contributions), or your total compensation from the Company during the year if less. If you exceed this limit, your Traditional After-Tax Contributions will be returned, and then other amounts may be returned or forfeited, as necessary so that your contributions for the year are within the IRS limits. You may generally change your contribution election or choose to stop contributing at any time. Contact Vanguard to start, stop or change your contribution amount by logging on to your account at


www.vanguard.com/retirementplans or calling a Vanguard Participant Services associate at (800) 523-1188 Monday through Friday from 8:30 a.m. to 9 p.m., Eastern Time. Eligible Compensation Generally, your eligible compensation used to calculate Pre-Tax Contributions, Roth 401(k) Contributions, Traditional After-Tax Contributions, Catch-Up Contributions, and Company Matching Contributions includes base salary and/or regular wages (including holiday and leave pay for regular scheduled work days), but does not include, among other earnings, bonuses, incentive compensation, commissions, equity awards, overtime, and lump sum payouts of paid time off at termination of employment. Base salary and/or regular wages shall also include amounts paid to an employee for working hours during a non-standard workweek that is 60 or more hours per week if the non-standard workweek is required by contract. Note that some fringe groups may have a different definition of compensation. Eligible compensation is limited by the IRS to $290,000 for 2021. This limit is subject to change each calendar year. About Social Security FICA taxes (Social Security tax and Medicare tax) are deducted from Pre-Tax Contributions, Roth 401(k) Contributions, Catch-Up Contributions, and Traditional After-Tax Contributions to the Plan. For this reason, gross wages upon which Social Security benefits will be based will not be impacted by the dollars you elect to contribute to the Plan. How Much Should You Save? How much should you be saving for your future retirement paycheck to yourself? If you are not sure, Vanguard makes online calculators available to help you decide. You can find the following online calculators and many others at https://vanguard.com/toolbox.

Plan Savings Calculator Use this calculator to see how even a small increase in your current retirement savings could affect your financial future. Figure out how much your savings will be worth in retirement, monthly retirement income, and the impact to your paycheck today.

Reach the Savings Limit Calculator

This calculator shows you how to adjust your contribution percentage so that you contribute the maximum allowed under the Plan and IRS limits and spread out your contributions evenly throughout the year in order to receive the maximum match

Retirement Income Calculator

This calculator helps you determine how much income you might need in retirement and whether or not you are on track.

Retirement Nest Egg Calculator

This calculator shows you how to figure out how long your retirement nest egg could last and how a few changes to your retirement savings rate could impact the final results.


Additionally, you can find other tools, including the 401(k) Quick Calculator and the Salary Deferral Modeling Tool, along with other helpful information, on the Leidos intranet on the Leidos, Inc. Retirement Plan Prism page. If you are in an eligible fringe benefit package that provides for a Company Matching Contribution, and you contribute less than the full amount that is eligible to receive a Company Matching Contribution, you may want to consider increasing your Pre-Tax Contribution and/or Roth 401(k) Contribution rate so you receive the full Company Matching Contribution.

Also, if you are in an eligible fringe benefit package that provides a Company Matching Contribution, you will receive a match for every pay period in which you make Pre-Tax and/or Roth 401(k) Contributions. If you reach the IRS deferral limit before the end of the year, you may miss out on receiving a portion of the Company Matching Contribution. Bargained Employees: refer to your collective bargaining agreement with Leidos for terms applicable to you. The Annual Increase Program

The annual increase program allows you to increase your Pre-Tax Contribution rate automatically one to three percentage points each year. It’s easy to participate in this program. Simply decide how much more you want to save (from one to three percentage points), and your Pre-Tax Contribution will automatically increase each year by whatever percentage you select. You can also select the month you want your Pre-Tax Contribution to increase each year. Increases will occur in January if you don’t choose a month. Here’s how it works: Suppose Joe earns a salary of $60,000, contributes 3% into the Plan as Pre-Tax Contributions, and elects an annual increase of one percentage point. After one year of saving, he has contributed $1,800 into the Plan (3% of $60,000). The next year, his Pre-Tax Contribution percentage increases from 3% to 4% of his eligible compensation, due to the automatic annual increase. You can sign up for the annual increase program at any time by logging on to your account at www.vanguard.com/retirementplans or calling a Vanguard Participant Services associate at (800) 523-1188 Monday through Friday from 8:30 a.m. to 9 p.m., Eastern Time.

Note: If you make changes to your contribution rate online, you will also be

asked to elect an annual increase percentage. If you do not want to participate in the annual increase program, enter 0% when prompted.

Rollover Contributions

If you are currently employed with the Company and have pre-tax and/or Roth 401(k) savings in a previous employer’s 401(k) plan, 403(b) plan, 457 plan or other type of qualified retirement plan, you may consider moving it to the Plan as a Rollover Contribution. You may also rollover after-tax amounts from a previous employer’s plan, as long as the after-tax amounts are directly rolled over to the Plan. Please note Puerto Rico Participants are not eligible to roll in Roth contributions.


Terminated participants who maintain an account with the Plan may also transfer pre-tax, Roth 401(k), and after-tax savings from a previous employer’s 401(k) plan to the Plan as a Rollover Contribution in accordance with Plan and IRS requirements.

Your Rollover Contribution will be placed in a rollover account, and you can choose your investment options from among the same options available for your elective contributions. Investment in the Leidos Common Stock Fund is limited to 50% of your overall Rollover Contribution. Your rollover account and any associated earnings are always 100% vested.

Log onto Vanguard at www.vanguard.com/retirementplans or call a Vanguard Participant Services associate at (800) 523-1188, if you would like to initiate a Rollover Contribution. In-Plan Roth Conversion

The Plan allows you to convert certain vested amounts in the Plan to Roth 401(k) after-tax money within the Plan. Excluded from conversion are Roth 401(k) Contributions, Rollover Contributions that are Roth amounts and prior in-plan Roth conversions. Please note Puerto Rico Participants are not eligible for In-Plan Roth conversions. Your in-plan Roth conversion account will hold your in-plan Roth conversion amounts and will be comprised of sub-accounts to separately allocate for amounts converted from different Plan accounts. Your in-plan Roth conversions and earnings thereon will be subject to the distribution restrictions that were applicable to such amounts before the conversion. Conversions of Traditional After-Tax Contributions may provide future tax-free earnings if all other Roth provisions are met.

Consult With a Tax Advisor Before Acting Converting to Roth is not right for everyone, as it depends greatly on your individual circumstances, including your current and estimated future tax rates. An election to convert pre-tax savings to post-tax Roth savings within the Plan is irrevocable and cannot be undone even if the value of the Roth account falls after the conversion. We recommend that you consult a tax advisor before taking any action. As you weigh your decision, here are two important questions to answer:

1. What will your tax obligation be on the conversion? The tax owed on a conversion could be significant. You should determine whether converting to Roth would raise your taxable income sufficiently to push you into a higher income tax bracket. You should also consider your source of funds to pay your taxes. Income taxes will not be withheld on the amount you convert to Roth. If you intend to pay the tax on the conversion by taking a withdrawal of Plan money and are under age 59½, you could owe a 10% federal penalty in addition to ordinary income taxes for the early withdrawal. [Note: the Plan also offers an election for automatic in-plan Roth conversions for your Traditional After-Tax Contributions each pay period so you can avoid taxes on conversion. Contact


Vanguard at 800-523-1188 for more information.]

2. Can you wait five years after converting before taking Roth withdrawals? A separate five-year holding period applies each time you convert eligible pre-tax money to Roth 401(k) after-tax money within the Plan. In general, if you withdraw Roth assets within five years of the conversion and before age 59½, you would owe a 10% early withdrawal tax on the portion of the withdrawal attributable to the conversion. In addition, you may also have to pay ordinary income tax as well as a 10% penalty on the portion of the withdrawal that represents Roth earnings.

More Questions about In-Plan Roth Conversions? To read questions and answers about in-plan Roth conversions, visit: https://retirementplans.vanguard.com/VGApp/pe/pubeducation/jumppages/RothConversionQnA.jsf

Company Contributions Company contributions are made at the discretion of the Company and can be changed or eliminated at any time. The Company currently makes Company Matching Contributions for employees in eligible fringe benefit packages. Bargained Employees: refer to your collective bargaining agreement with Leidos for terms applicable to you. Company Matching Contributions Company Matching Contributions are made entirely by Leidos and are based on the Pre-Tax Contributions and Roth 401(k) Contributions that you make each payroll period if you are covered by an eligible fringe benefit package. Company Matching Contributions are made each payroll period. The percentage of Company Matching Contributions you are eligible to receive is based on your fringe benefit package and collective bargaining agreement, if applicable. You can find your fringe benefit package information listed in your personal data on Workday under View Profile, Job, then Organizations (Leidos - Fringe), or you can contact the Enterprise Business Operations HR department via email at [email protected] or via phone at 855-553-4367, option #3, between 8 a.m. – 6 p.m. ET, Monday-Friday for that information. A document detailing fringe eligibility is posted on the Leidos, Inc. Retirement Plan Prism page under Quick Links & Resources. The IRS sets a compensation limit on the amount of eligible compensation that can be included in determining Company Matching Contributions. The IRS compensation limit for calendar year 2021 is $290,000. If your eligible compensation for 2021 exceeds this limit, the Plan can only consider $290,000 as eligible compensation for determining your Company Matching Contributions. Company Matching Contributions are made each payroll period. You will be eligible for Company Matching Contributions only if you make eligible, elective contributions to the Plan and meet any other eligibility requirements specific to your fringe benefit package and collective bargaining agreement, if applicable. If you are eligible to receive a Company Matching Contribution, in order to maximize the Company Matching Contributions that you receive, be sure to contribute the full amount that is eligible to receive a Company Matching Contribution as Pre-Tax Contributions and/or Roth 401(k) Contributions, and spread out your contributions over each pay period. If you reach the IRS contribution limit before the end of the


year, your Company Matching Contributions will stop when your eligible contributions stop. All Company Matching Contributions are invested in the same way as you have elected to invest your elective contributions. See “How Contributions Are Invested” for more details about the Plan’s investment options.

Any Company Matching Contributions and related earnings will be taxed at ordinary income tax rates when distributed from the Plan regardless of whether they were matched against Pre-Tax Contributions or Roth 401(k) Contributions. The following types of contributions are not matched by the Company:

CODA Deferrals Traditional After-Tax Contributions Contributions in excess of Plan limits Elective contributions by participants not in an eligible fringe benefit package

How Contributions Are Invested When you become a participant in the Plan, you may choose from a wide variety of investment options for your employee contributions and Company contributions. How you invest your contributions and account under the Plan is entirely up to you. When choosing your investment options, consider your needs and the different risks involved. Your investment decisions may result in gains or losses to your account in the Plan. The Company assumes no responsibility for the results of your investment decisions. ERISA imposes certain duties on the parties who are responsible for the operation of the Plan. These parties, called fiduciaries, generally have a duty to invest the Plan assets in a prudent manner. However, an exception exists for plans that comply with ERISA Section 404(c) and permit participants to exercise control over the assets in their accounts and choose from a broad range of investment alternatives. This Plan is intended to be a Section 404(c) plan. This means that you and not the Plan fiduciaries are responsible for the investment decisions you make. The Plan has a Qualified Default Investment Alternative (QDIA), which acts as the “default” investment fund if you enroll in the Plan but do not choose investments for your contributions. The QDIA for the Plan is the Vanguard® Target Retirement Trusts. If you do not make an investment election, your account will be invested in the date-specific Vanguard Target Retirement Trust that most closely matches your expected retirement year (based on an assumed retirement age of 65). Investments in Target Retirement Trusts are subject to the risks of their underlying funds. The year in the trust name refers to the approximate year (the target date) when an investor in the trust would retire and leave the workforce. The trust will gradually shift its emphasis from more aggressive investments (stocks) to more conservative ones (bonds and short-term reserves) based on its target date. An investment in a Target Retirement Trust is not guaranteed at any time, including on or after


the target date. You can change the investment of your contributions at any time. In addition, you can “exchange” already invested money from one or more funds to other funds at any time, subject to any restrictions that may apply to individual investment options from time to time. See the “Your Investment Options at a Glance” for more information on the investment options provided in the Plan. Please note that the Leidos Retirement Plans Committee has claimed an exclusion from the definition of the term “commodity pool operator” under the Commodity Exchange Act for the operation of the Leidos Retirement Plan Master Trust. Therefore, the Leidos Retirement Plans Committee is not subject to registration or regulation as a “commodity pool operator” under that Act.

The Importance of Reading a Fund Prospectus, Fact Sheet or Annual Report The fund literature for each investment fund contains important information concerning that fund, including the risks and expenses of investing. You should read the entire document for any fund (including this Summary Plan Description and the Supplement to Prospectus and Summary Plan Description for more information about Company Stock) before you decide to invest.

Leidos Stock Funds The Leidos Stock Funds invest primarily in the common stock of our parent Company, Leidos Holdings, Inc. However, like a stock mutual fund, the funds also maintain a small cash amount, which helps facilitate transactions (such as distributions and fund exchanges). All Leidos Stock Fund balances are exchangeable into any other fund offered by the Plan. The Plan holds two separate Company Stock funds. Leidos Common Stock Fund The Leidos Common Stock Fund invests primarily in Company Stock and has a small cash amount to facilitate transactions. You may direct up to 50% of your contributions into the Leidos Common Stock Fund. You can make exchanges into and out of the Leidos Common Stock Fund at any time. Leidos Closed Stock Fund (Formerly the SAIC Preferred Stock Fund) The Closed Stock Fund has been closed to new investments since April 2007; however, participants can still make exchanges out of the fund at any time. The Leidos Closed Stock Fund was formerly named the SAIC Preferred Stock Fund. In November 2009, Leidos reclassified all shares of class A preferred stock into shares of common stock on a one-for-one basis. At that time, all class A preferred shares held in the SAIC Preferred Stock Fund automatically became shares of common stock and the fund was renamed the SAIC Closed Stock Fund and later the Leidos Closed Stock Fund.


Transfers Into and Out of the Leidos Stock Funds You can make exchanges out of either of the Leidos Stock Funds at any time. You can also exchange into the Leidos Common Stock Fund at any time. If you transfer into or out of the Leidos Stock Funds, in most cases you will receive the unit value corresponding to the closing price of the Leidos Stock Fund on the day your transaction was requested. For distributions or fund exchanges, participant requests received before 4 p.m. Eastern Time are valued at the unit price of the fund for that day. Requests received after 4 p.m. Eastern Time are valued at the unit price for the next business day. However, in order to minimize trading impact, market conditions may require that shares are traded over a period of days and the price received will be the weighted average price.

You should be aware that there are risks involved in purchasing shares of Company Stock. For example, Company Stock may be riskier than other investments because it is not diversified. Neither the Company nor any of its officers or directors is making a recommendation that you purchase Company Stock. You should carefully review your financial objectives and other investments and consult your financial advisor before investing in Company Stock. You should also carefully review this summary, the Supplement to Prospectus and Summary Plan Description and the information incorporated by reference herein prior to making a decision to invest in the Leidos Common Stock Fund.

Your ability to make investments into or out of the Leidos Stock Funds may be restricted as necessary to comply with the Company’s insider trading policy or applicable securities laws. Valuation of Leidos Stock Fund Accounts The value of your account balance held in the Leidos Stock Funds will be based on the value of Leidos, Inc. common stock, which is publicly traded on the New York Stock Exchange under the symbol “LDOS.” Fund Valuation With Unit Values For record keeping purposes, the Leidos Stock Funds are valued in fund units — rather than shares of stock. Each fund unit represents a portion of your ownership in the fund. The funds’ unit values are determined daily by dividing the total value of each fund by the number of units credited to all participants in the Leidos Stock Fund. The unit values may change daily, primarily as a result of the value of the underlying shares of Company Stock and the fund’s cash position. To determine the approximate number of whole shares of Company Stock represented by your units, divide the market value of your Leidos Stock Fund account by the current share price of Leidos, Inc. common stock.

Keeping Track of Your Account You can keep track of your account value and investment options anytime, 24 hours a day, seven days a week, through Vanguard’s website. You can also reach Vanguard by telephone, through Vanguard’s interactive voice response system or by reaching a Participant Services associate during


business hours.

Contact Vanguard at (800) 523-1188 or visit http://www.vanguard.com/retirementplans for Plan account information.

How Vesting Works Vesting refers to your right of ownership of the amounts in your account. If you are 100% vested in a given account, you have the right to take that account (adjusted for investment gains and losses) with you when you leave the Company. You may become vested in certain types of Company contributions over a period of time, as described below.

Vesting of Your Contributions You are always 100% vested in the following accounts, including any investment income on your contributions:

Pre-Tax Contributions CODA Deferrals Roth 401(k) Contributions Catch-Up Contributions Rollover Contributions Traditional After-Tax Contributions

Vesting of Company Contributions Company contributions, which include Company Matching Contributions, and historical Company contributions (including the 2% annual Company contribution, ESOP contributions and profit sharing contributions), are subject to a Vesting schedule, meaning that you earn a right to these amounts (adjusted for investment gains and losses) based on your Years of Service with the Company. If you are a Leidos employee on or after January 1, 2018:

Your Years of Service Portion of Account Vested

Up to One Year 0%

1 Year 25%

2 Years 50%

3 Years 100%

Once you have three Years of Service, your account is fully vested and any future Company Matching Contributions made to your account will be immediately vested.


If you terminated your employment with the Company on or before December 31, 2017, the Vesting schedule was over 5 years. Once you accrued five Years of Service, your account became fully vested and any Company contributions made to your account after that date were immediately vested. If you leave the Company prior to 100% Vesting, any unvested portion of your Plan account will be forfeited. Forfeiture occurs after 5 consecutive one-year Breaks-in-Service. Forfeitures may be used by the Company to pay reasonable Plan expenses, reinstate prior forfeitures for participants who are rehired, or used to offset Company contributions (including Company Matching Contributions). Full Vesting also occurs at age 59½, total disability or death while employed by Leidos. In addition, if a participant dies while in “qualified military service,” as defined under IRS rules, the participant will be treated as having died while still employed by Leidos, Inc. or a participating affiliated company. You are also 100% vested in the dividends you receive on Company contributions invested in Company Stock held in the Leidos Stock Funds, even if the Company contributions are not entirely vested.

How Service Is Counted The Plan keeps track of your Hours of Service and Years of Service with the Company to determine what percentage of your benefit is vested. If you leave the Company and return at a later date, or if you go on a leave of absence and later return, your prior service will count for Vesting purposes. In addition, your prior service earned under certain contracts or through acquisitions may also count for Vesting purposes. What Is an Hour of Service? Hourly employees will be credited with an Hour of Service for each hour of working or nonworking time (e.g., vacation, sick leave, jury duty) for which they are paid or entitled to be paid by the Company. Salaried employees paid every two weeks are credited with 45 hours for each week of service, regardless of the actual number of hours worked.

You earn one year of Vesting service for each calendar year in which

you complete 850 or more hours of service.

What Is a Year of Service? A Year of Service for Vesting purposes is any calendar year during which you complete 850 or more Hours of Service. If you were an employee as of January 1, 2006, or later, you will also receive credit for any Years of Service performed before the Computation Period during which you turned age 18.


You will receive only one Year of Service with respect to services performed in a single calendar year, no matter how many Hours of Service you are credited with during that year. So, for example, if you earned 2,000 Hours of Service in a calendar year, you will be credited with only one Year of Service, even though you have worked more than twice the minimum 850-hour requirement. What Is a Break-in-Service? In general, a Break-in-Service is a significant period of time during which you are not earning Hours of Service that count toward Vesting. More specifically, a one-year Break-in-Service is any 12-month Computation Period during which you have 425 or fewer Hours of Service. What Happens If You Have a Break-in-Service? If you terminate from the Company prior to completing 425 hours during your first Year of Service, you will lose all Hours of Service completed before your Break-in-Service for all Plan purposes. If you terminate from the Company and have a Break-in-Service after you have completed one Year of Service, you will become eligible to participate in the Plan again on the day that you first perform an Hour of Service for the Company after you are reemployed. You will forfeit any unvested balances upon receiving distribution of your vested amounts following your termination of employment. If you are rehired prior to five consecutive Break-in-Service years, your forfeited account balance will be reinstated if you repay the amount distributed to you within five years following reemployment or prior to five consecutive Break-in-Service years after the distribution, whichever is earlier. If you have five consecutive Breaks-in-Service prior to receiving a distribution, you will forfeit your unvested balances at that time. What Happens If You Have a Leave of Absence? Leidos may grant a leave of absence for various reasons, such as illness, injury, parental leave, jury duty, or military leave. For Military Service: If you take a leave of absence to enter compulsory military service, federal law protects your rights to make up your missed elective contributions, provided you return to work for the Company after completion of your military service during the period of time required by law.

For assistance with questions regarding your outstanding loans and options for your retirement account when you are on leave, contact Vanguard at (800) 523-1188.

For Unpaid Parental Leave:

If you take an unpaid parental leave, you will receive credit for up to a total of 426 Hours of Service, if necessary, to avoid a Break-in-Service. These hours are first credited (as necessary to avoid a Break-in-Service) to the year your leave started, and the remaining hours will be credited in the following year, assuming the leave extended into that year.


For Other Reasons:

Time spent on any other authorized unpaid leaves of absence will not count toward your Hours of Service for Plan purposes. For information on loan repayments when you are on leave, please see “Repaying Your Loan” below.

Taking a Loan From Your Account Although the Plan is designed for long-term savings, you may borrow from your account for any reason and pay your account back with interest. How Much You May Borrow You may have up to two outstanding Plan loans at any given time. Only one of these loans may be used for the purchase of your principal residence, which will have a longer repayment period. There is a current fee of $35 for an online loan application and $85 for loan applications made using Vanguard Participant Services at (800) 523-1188. In addition, a $25 annual loan maintenance fee will be charged for every year the loan is outstanding. The minimum loan amount is $1,000 for each loan. The maximum loan amount is 50% of your vested account balance up to $50,000 less any outstanding Plan loan balance over the past rolling 12 months. Contact Vanguard at (800) 523-1188 or visit www.vanguard.com/retirementplans to apply for a Plan loan or withdrawal. Repaying Your Loan You repay your loan over time with regular payroll deductions. The repayment period depends on the purpose of your loan:

General purpose loans: You may take up to 60 months to repay your loan.

Loans used for the purchase of your primary residence: You may take up to 30 years to repay your loan.

If you transfer employment to a non-participating subsidiary or terminate employment before your loan is paid, you can continue repaying your loan by setting up an automatic payment to Vanguard from your bank account. Following your transfer or termination, you should contact Vanguard to establish your repayment schedule. If you do not contact Vanguard and your loan becomes delinquent, Vanguard will provide you with a final opportunity to bring your loan balance current, however if you do not begin repayment by converting your loan to an ACH repayment schedule, your loan will default and any unpaid balance will become taxable income to you. You typically make payments on your loan through regular payroll deductions, however, should you


miss regular payroll deductions, loan repayments must be made at least quarterly to avoid default. Loan repayments may be made directly to Vanguard as needed to avoid default. However, if you are on a leave of absence due to military service or if you are on an unpaid, non-military leave of absence, your loan repayments may be suspended. For military service, your loan repayments may be suspended during the length of leave and reamortized when you return from leave. For unpaid, non-military leaves of absence, your loan repayments may be suspended for the duration of the leave or one year, whichever is shorter, and will be reamortized upon return from leave of absence or the end of the one year period, whichever occurs first. However, please note, in all events, you must repay your loan by the 60-month or 30-year timeframes set forth above. Outstanding loans maintained under the Leidos, Inc. Retirement Plan for Former IS&GS Employees and the Leidos, Inc. Retirement Plan Bargaining Employees that were merged with and into the Plan as of December 29, 2017 are subject to the terms of the outstanding promissory note and will not be subject to Vanguard loan maintenance fees.

Withdrawals

While You Are Actively Employed While you are actively employed you can access assets in your account in the event of a severe financial hardship or once you reach age 59½. You can also access Traditional After-Tax Contributions and Rollover Contributions, and related earnings on those amounts, while actively employed. There may be additional tax consequences of taking a withdrawal while you are actively employed. See “Tax Considerations” in the Supplement to Prospectus and Summary Plan Description for more information. Hardship Withdrawals You can withdraw money from your account while you are still actively employed if you, your dependents or Beneficiary experience an immediate and heavy financial need. You may request a hardship withdrawal from your Pre-Tax Contributions, CODA Deferrals, Roth 401(k) Contributions, and Catch-Up Contributions, including earnings. You can also receive a hardship withdrawal from your Company contributions (including your Company Matching Contributions and historical Company contributions), including earnings, if you are 100% vested in such amounts. The hardship withdrawal will be made pro rata from the funds in which your Plan account is invested, including any reinvested Company Stock dividends within your account.

Some examples of financial hardship include:

Purchase of a primary residence for you Unreimbursed medical expenses for you, your spouse, your dependents, and your primary

Beneficiary(ies) Tuition and fees for postsecondary education for you, your spouse, your dependents, and

your primary Beneficiary(ies) Prevention of eviction or mortgage foreclosure on your primary residence Funeral expenses for certain family members and your primary Beneficiary(ies)


Certain expenses for repairing your principal residence if the expenses qualify as a casualty deduction

Expenses resulting from a Federally declared disaster in the same area as your principal residence or place of employment

Before making a hardship withdrawal, you must first exhaust other withdrawal options, such as any eligible in-service withdrawals including a request of dividends on Company Stock within your account, from this Plan or any other company-sponsored retirement plans. The minimum hardship withdrawal is $500. In addition, your withdrawal cannot exceed the amount of the immediate and heavy financial need (plus certain reasonably anticipated tax and penalty amounts).You are not required to take a loan before applying for a hardship withdrawal, and your contributions will continue unless you choose to stop or change them. Please note there may be special provisions granted from time to time related to disaster relief. Qualified Birth or Adoption Withdrawal Effective April 5, 2021, if you become a parent through birth or adoption, you are eligible to elect a distribution of up to $5,000 for birth or adoption of the child from your account. You will need to make the election within one year of the birth of the child or finalization of the adoption of the child, and provide certain information at the time of the election. The withdrawal is not subject to the 10% early withdrawal tax, and no mandatory withholding will apply, although you must still pay taxes on the amount distributed. You will also have the ability to recontribute the amount of the withdrawal in the future as a rollover amount. Withdrawals After You Reach Age 59½ Once you reach age 59½, you can make full or partial withdrawals from your entire vested account balance and take an in-kind distribution from any Leidos Stock Fund balance, even if you are still actively employed with Leidos. To receive an in-kind distribution and receive favorable tax treatment, you must take a distribution of your entire Plan account balance (see “Receiving a Distribution” on page 25). Please reach out to Vanguard or your personal financial advisor for guidance. Rollover Withdrawal The Plan allows you to take an in-service withdrawal of assets that you rolled over from another plan (and related earnings) regardless of your age. However, if you are under age 59½, you could owe a 10% penalty tax in addition to ordinary income taxes for the early withdrawal. Traditional After-Tax Contribution Withdrawal The Plan allows you to take an in-service withdrawal of your Traditional After-Tax Contributions (and related earnings) regardless of your age. You would not pay additional taxes or penalties on your contributions, however, if you are under age 59½, you could owe a 10% penalty tax in addition to ordinary income taxes for the early withdrawal of any earnings. Withdrawals Due to Military Service If you are ordered or called to active military duty, and such active duty is for a duration of 180 days or more or for an indefinite period (i.e., you are a “Qualified Reservist”), then (in addition to any Traditional After-Tax Contributions) you may elect to withdraw your Pre-Tax Contributions,


CODA Deferrals, and Roth 401(k) Contributions from the Plan. Such withdrawal can be made at any time during the period beginning on the date of such order or call to active duty and ending on the date that such active duty ceases. If you are on active military duty for more than 30 days, you will be deemed to have incurred a severance of employment ("deemed severance") and will be eligible to take a distribution from the Plan. If you request a distribution upon a deemed severance of employment, you will not be permitted to make any contributions to the Plan for six months following the date of the distribution. Dividends The Plan allows you to elect to receive a distribution of any dividends paid on Company Stock held in the Leidos Stock Funds each quarter. The dividends distributed to you will be taxed as ordinary income, but are not subject to the 10% early withdrawal tax even if you are under 59½. Distributed dividends are not eligible rollover amounts. Remember that if you elect to receive a distribution of dividends, those amounts will not be saved under the Plan for when you retire. If you do not elect to receive a distribution of the dividends, they will automatically be reinvested in Company Stock. You are 100% vested in all of the dividends reinvested in the Plan. You can reinvest those amounts in accordance with the terms if the Plan. Reinvested dividends will be subsequently distributed in accordance with Plan terms, including being able to be rolled over to another qualified plan or IRA. The reinvested dividends will be taxed when they are distributed, except for dividends attributable to Roth amounts which may be tax free if they are part of a qualifying distribution. Please note that if you take a hardship withdrawal, you will be deemed to have elected to receive a distribution of the dividends. If you have questions about the process to elect a distribution of dividends on Company Stock held in the Leidos Stock Funds, check online at www.vanguard.com/retirementplans or call (800) 523-1188. Withdrawals When You Are No Longer Actively Employed When and How Benefits Are Paid You are entitled to receive your vested account balance upon termination of employment with the Company and all subsidiaries and affiliates, or total and permanent disability. At that time, you may do any of the following:

Leave your account balance in the Plan* Roll in other employer’s qualified plan account balances or an IRA to your Leidos account Begin a new loan from your Leidos account and repay directly to Vanguard Take a distribution from the Plan: o As a lump-sum cash payment o As an in-kind stock distribution of Leidos Stock Fund balances

(see “Receiving a Distribution” on page 25) o As installment payments set up monthly, quarterly, semiannually, or annually. See

“Taking Your Distribution As Installment Payments” below.


o As a rollover to another employer’s qualified plan or an IRA o In unlimited partial withdrawals

*If your vested account balance is over $5,000, you can leave your account in the Plan after your separation, taking advantage of the benefit of reduced investment fees and other features available through the Plan. (If your account balance is under $5,000 and you are making loan payments, the balance will not be cashed out due to an outstanding loan balance.)

After termination, if your vested balance is between $1,000 and $5,000 and you don’t elect a distribution of your benefit, you will receive a mandatory distribution of your account balance within 12 months of your termination date or as soon as is administratively possible. If you fail to provide the Plan with instructions on whether you prefer a distribution to you or a rollover to an IRA or other qualified plan, the Plan will establish an IRA on your behalf through Vanguard. The amount rolled over to the IRA will be invested in a manner to preserve principal and provide a reasonable rate of return and liquidity. Your IRA account will be charged applicable fees. For further information regarding the IRA, you can contact Vanguard’s Retail Assistance Line at 1-877-662-7447. If your vested balance is less than $1,000 after termination and you don’t elect a distribution option, you will receive a taxable lump-sum distribution of your balance within 12 months of your termination date. The following exceptions apply:

- If you have an outstanding loan, you may continue to make loan repayments until the loan is paid in full regardless of your vested account balance.

- If you have started installment payments, they will continue regardless of your vested account balance.

Leaving Your Money in the Plan If your vested account balance is over $5,000, you can leave your money in the Plan. However, you will generally be required to take a distribution of at least the IRS required minimum distribution amount by April 1 of the year following the date you reach age 72 (or age 70 ½ if you reached age 70 ½ prior to January 1, 2020). This includes any pre-tax, CODA, and Roth 401(k) contributions, earnings from traditional after-tax and rollover monies held in your account. To avoid having Roth 401(k) assets subject to the IRS required minimum distribution, you may want to consider rolling out your Roth 401(k) assets to a Roth Rollover IRA before attaining age 72. You should speak with a financial planner to determine the best options for your personal circumstances. In addition to managing your account under the Plan, you may also roll over other employer plan account balances and certain individual retirement accounts (IRAs) into your Plan account to better manage your retirement savings in a single place.


Receiving a Distribution If you elect to receive a cash distribution, it will be made to you in a single lump-sum payment, one or more partial lump sum payments and/or installment payments. Please note, installment payments are only available for withdrawals when you are no longer actively employed. You may take your Leidos Stock Funds balance as a cash distribution or an in-kind distribution of Company Stock as described below. Upon your death, any remaining amounts will be paid to your Beneficiary(ies). See “Tax Considerations” in the Supplement to Prospectus and Summary Plan Description for more details about taxation of distributions and potential penalties for early distributions. Please note that if your Plan account includes amounts that are payable as a qualified joint and survivor annuity, and you are married, your spouse must consent to the distribution of that portion of your account. Taking Your Distribution In Kind as Leidos Stock If you are a former employee, your vested balance in the Leidos Stock Funds can be taken as an in-kind distribution; that is, in shares of Leidos, Inc. common stock. Active employees who are eligible for an in-service withdrawal (age 59½ or older) may also elect an in-kind distribution. You can elect whether to take your entire Leidos Stock Funds account balance in kind, or you can take a partial in-kind share distribution and take the remainder of your Leidos Stock Funds account balance in the form of cash or possible rollover to an individual IRA. Note: Lump sum, in-kind distributions of Company Stock that meet special IRS requirements may be able to receive special tax treatment, including having the appreciation in the value of the stock being taxed at capital gains tax rates when the stock is later sold. However, tax laws are complicated and change from time to time. The Company recommends that you consult your tax advisor before deciding whether an in-kind distribution is right for your particular situation. Taking Your Distribution as Installment Payments If you are a terminated Participant (regardless of age), you may elect to receive all or part of your distributable benefit as installment payments. You can elect to receive installment payments monthly, quarterly, semi-annually or annually. You may structure your payments so payments are made: 1) for the duration of your life; 2) as a series of declining balance distributions over an elected period; 3) as a fixed dollar amount of your account; or 4) as a fixed percentage of your account. The amount of the installment payment will depend on your account balance at the time of the installment payment and the number of remaining installment payments. If you choose to receive installment payments, you may still elect to receive a full or partial lump sum payment of your remaining account balance. Any elections to receive a full or partial lump sum payment after installment payments begin will reduce the amount of future installment payments. Rollovers to Another Qualified Plan or IRA If you leave the Company, you may move your account to the qualified plan of your next employer (if that employer accepts Rollover Contributions), or you may have your account moved directly to a Rollover IRA, an IRA that accepts funds distributed from qualified retirement


plans. You may be able to avoid immediate taxation on your account if you choose one of these options. You may rollover any Roth 401(k) money in your account to a Roth Rollover IRA. If you qualify, you may also rollover your pre-tax account into a Roth IRA; however, the pre-tax amounts you rollover into a Roth Rollover IRA will be taxed. Pre-tax rollovers into a Roth IRA can be a complex process you should consult your tax advisor if you are considering a rollover. Distributions from the Plan will be subject to federal income tax under special, complex rules that apply generally to distributions from tax-qualified retirement plans. These rules are summarized in the Supplement to Prospectus and Summary Plan Description, and in a Special Tax Notice that is provided by the Plan prior to taking your distribution. A copy of this notice is available through Vanguard. Other Tax Information Please review the Supplement to Prospectus and Summary Plan Description for a summary of additional federal income tax rules concerning the Plan.

Beneficiary Information You should have a Beneficiary election on file with Vanguard designating who will receive your Plan account upon your death. If you do not have a Beneficiary on file with Vanguard at the time of your death, your Plan assets will be distributed to your spouse if you are married, or to your estate if you are not married. You can add or update your Beneficiary information online at www.vanguard.com/retirementplans. You may change your Beneficiary designation at any time. Please note the following:

If you wish to designate a Beneficiary other than your spouse, your spouse must consent in writing except in certain limited situations. This consent by your spouse must be witnessed by a notary public.

You may identify “primary beneficiaries” and “contingent beneficiaries” as your Beneficiary. Your primary Beneficiary receives your account if you die. If you name more than one primary Beneficiary, the primary beneficiaries will split your account as you direct. If one of the primary beneficiaries dies before you, the remaining primary beneficiaries will split your account if you die. If you name someone other than your spouse as a primary Beneficiary, your spouse must consent to the designation as noted above.

Your contingent beneficiaries receive your account only if there are no primary beneficiaries alive when you die. In that case, your account would be paid to the contingent beneficiaries.

If your spouse is named as a Beneficiary and your marriage is dissolved prior to the full distribution of your Plan assets, your former spouse and the heirs or other


Beneficiaries of your former spouse will not be entitled to receive your benefits from the Plan unless you execute another Beneficiary designation clearly naming your former spouse as a Beneficiary after the marriage is dissolved.

If a minor is designated as a Beneficiary, any payments on behalf of the minor will be made to the minor’s living parent or parents or, if no parent of the minor is living, to a custodian selected by the Committee, in both cases, to hold such funds as custodian.

If a conservator has been legally appointed for any Beneficiary, any payments on behalf of the Beneficiary will be made to the conservator.

In certain situations, your designated Beneficiary may not be entitled to benefits. Specifically, if your Beneficiary dies within 120 hours of your death, your Beneficiary will be deemed to have passed away before your death, and will not be entitled to any death benefits. Also, if your Beneficiary is convicted, pleads guilty, or pleads no contest in connection with an intentional action resulting in your death, or applicable law would prohibit your Beneficiary from receiving benefits as a result of your death, your Beneficiary will be deemed to have passed away before your death, and will not be entitled to any death benefits.

Timing of Death Benefit Distributions Timing of death benefits is dependent on the type of Beneficiary receiving your account balance. In the event of your death after December 31, 2019, your account must generally be distributed within 10 years of your death. Certain exceptions on the timing of distributing your account may apply to your spouse, minor children, and other named beneficiaries who are not more than 10 years younger than you. In those cases, your Beneficiary is generally able to have the benefit paid out over their life expectancy (or by the end of the 10 year period after the minor child reaches age of majority). Beneficiaries may also be able to rollover an inherited Plan account balance to an inherited IRA. Please speak with your financial advisor, or Vanguard, for additional information. We recommend that you review your Beneficiary information on file with Vanguard to ensure that your records are up-to-date. You can obtain a new Beneficiary form from the Vanguard website. Note to beneficiaries: If the account owner died between January 1, 2015 and December 31, 2019:

Please note that the rules for beneficiaries have changed effective January 1, 2020. Prior to this date, beneficiaries had to take a full distribution of the account by December 31 of the fifth year following the original account owner’s death. However, under the new rules, if the original account owner died between January 1, 2015 and December 31, 2019, you have an additional year to take the remaining balance. Your advisor, or Vanguard, can provide additional information.


If you die on or after January 1, 2020, the following chart provides a general description on how your Plan account would be distributed. The rules related to the required minimum distributions are complex, and the IRS may issue additional rules and interpretations on the subject from time to time. You may want to consult with your tax adviser or financial planner about planning for required minimum distributions.

Type of Beneficiary Individual(s) or Entity Timing of Distribution No Designated Beneficiary

If married, automatically goes to spouse If not married, automatically goes to estate

Spouse – same as Eligible Designated Beneficiary Estate – If the death was before the participant’s required beginning date for distributions, then the entire account must be withdrawn within 5 years of participant’s death.

Eligible Designated Beneficiary

Spouse May take distributions over their life expectancy or may choose to take distributions by the end of the 10th year after the participant’s death. Surviving spouse may delay commencement of distribution until the later of: 1) the end of the year that the participant would have attained age 72, or 2) the surviving spouse’s required beginning date at age 72.

Minor Child May take distributions as desired but must take remaining distribution within 10 years after reaching age 18.

Disabled individual, chronically ill individual, including trusts for the exclusive benefit of these individuals

May take distributions over their life expectancy.

Individual not more than 10 years younger than account owner (employee)

May take distributions over their life expectancy or may choose to take distributions by the end of the 10th year after the participant’s death.

Non-Eligible Designated Beneficiary

Other individual not listed above

Must withdraw the entire account by the 10th calendar year following the year of the participant’s death.

Note: non-spousal beneficiaries can rollover an inherited Plan account balance to an inherited IRA. This option provides your Plan beneficiaries with an additional distribution choice upon your death. Please speak with your financial advisor, or Vanguard, for additional information.


Learning More About the Plan Vanguard is the record keeper for the Plan. You can access Vanguard’s resources through the internet or by telephone. Online Access To reach Vanguard via the internet, log on to www.vanguard.com/retirementplans. For security reasons, you must register for online account access. You will need your Record Keeper Plan number, which is 090518 for non-bargained employees and 094548 for bargained employees. Active employees can also visit the Leidos, Inc. Retirement Plan Prism page. You can also find general information about the Plan without logging in at www.vanguard.com/leidos for non-bargained employees and http://www.vanguard.com/leidosbargained for bargained employees. Telephone Access For access to your account information, call Vanguard’s 24-hour automated VOICE® Network at (800) 523-1188. You will need a personal identification number (PIN) to use VOICE. If you need assistance, press 0 to speak with a Participant Services associate. Associates are available Monday through Friday from 8:30 a.m. to 9 p.m., Eastern Time. You can conduct the following account transactions at any time by calling Vanguard:

Start or stop contributing, or change your payroll deduction Change the investment direction of future contributions Transfer money between funds Request loans and withdrawals

Other Information You Should Know You may obtain additional information from the Leidos Retirement Programs Department (email: [email protected]) regarding any of the following situations. Employment Transfers If you transfer employment to another employer owned by the Company that does not participate in the Plan, special rules apply:

You can no longer make contributions into the Plan. Also, you will not be eligible to receive additional Company contributions after you transfer to the non-participating employer.

Your service with the employer will still count towards determining your Vesting service. You will still be able to request loans from the Plan if you do not have two loans

outstanding. You should contact Vanguard to establish your repayment schedule and method on any existing or new loans.

You will still be able to request withdrawals that are available when you are actively employed – hardship withdrawals, withdrawals after you reach age 59½, withdrawals of


rollover distributions, withdrawals of After-Tax Contributions, withdrawals due to military service, and withdrawals of dividends paid on Company Stock. See the “Withdrawals: While You Are Actively Employed” section for more information.

You are not eligible to take a “termination” distribution of your Account when you transfer to a subsidiary or affiliate because you are still an active employee of the Company.

Loss or Denial of Benefits In general, if you terminate employment prior to completing three Years of Service, you will forfeit the unvested portion of your accounts. This section discusses various factors that may affect your eligibility for, and amount of, benefits under the Plan. Changes in Job Classification or Group Changes in your job classification such as a promotion will not, in general, affect your ability to participate in the Plan. However, salary reductions or increases may affect the amount of your contributions as well as Company contributions. Should you be transferred to a fringe rate group that is not eligible for the Plan, you may become ineligible to participate in the Plan or no longer be entitled to receive Company contributions. You will still be entitled to your vested account balance in the Plan, and service with the Company, including affiliates, will apply to determine your vested status. Loss in Account Value The Plan’s investment options, including the Leidos Stock Funds, may decline in market value, which may reduce the amount payable to you. The Company does not guarantee the value of your account, nor does the federal government. Qualified Domestic Relations Order In connection with divorce and child support matters, it is possible that an award of a portion of your account will be made to your former spouse or the guardian of your children. If the award is made as a result of a Qualified Domestic Relations Order (QDRO), the Plan will be required to make payments to the party to whom such award is made, and your benefits will be reduced accordingly. The maximum interest that can be assigned by a qualified domestic relations order to an alternate payee under the Plan is limited to the vested interest of your account. You can obtain a copy of the QDRO procedures, without charge, by contacting Vanguard at (800) 523-1188. The fee associated with the determination of any qualified status of a domestic relations order is $350. Please note that the fee may vary. To obtain the current fee structure as well as information regarding a QDRO, contact Vanguard at (800) 523-1188. This fee will be charged directly to your account. Under the terms of a QDRO, however, the fees may be charged to the non-employee payee or divided equally between you and the non-employee party to whom the award is made in connection with the implementation of the order. For example: Suppose a participant’s account is valued at $12,000 and is fully vested, and the non-employee alternate payee has been awarded 50% of the participant’s account value. The fee to determine that the domestic relations order is qualified is $350, however, under the terms


of the QDRO the non-employee alternate payee agrees to absorb the full cost of the review and determination of the qualified status of the order. The account balance is otherwise split equally between the participant and the non-employee payee. In this case, the participant’s account will be charged $350, the participant will retain $6,000, and the non-employee payee will have an account of $5,650 ($6,000 - $350). Conversely, if the participant and the non-employee payee agree to equally split the $350 fee, each will have an account of $5,825. Please note that the fee used in the above example may vary. To obtain the current fee structure as well as information regarding a QDRO, contact Vanguard at (800) 523-1188. Lost Participant or Beneficiary In the event that you, or your Beneficiary, cannot be located when your benefit under the Plan is due to be paid, the Plan Administrator will take reasonable efforts to find you or your Beneficiary. If you, or your Beneficiary, are still unable to be located, your account under the Plan will be forfeited. If you, or your Beneficiary, later make a valid claim for benefits, your account will be reinstated based on the value as of the date it was previously forfeited, and paid to you, or your Beneficiary. Plan Changes The Company expects to continue the Plan indefinitely, but reserves the right to change the Plan or to permanently discontinue contributions to the Plan at any time, and for any reason, in its sole discretion.

The Committee has the authority to make administrative and regulatory changes to the Plan. For example, the Company or the Committee may alter the rules or procedures, under which the Plan is operated, including, for example, the investment alternatives and procedures, loan procedures and availability, timing and method of valuing accounts, timing of distributions, etc. The Company may also decide to discontinue making Company contributions, including Company Matching Contributions. In any event, the Company may not make any changes to the Plan that would reduce benefits that you have already accrued in your account. Plan Termination The Company expects to continue the Plan indefinitely. However, the Company reserves the right to discontinue the Plan, in part or in whole, at any time, and for any reason, in its sole discretion. If the Plan is discontinued, the Company will make no more contributions to the Plan, and you will be fully vested in all benefits accrued (and funded) on the date the Plan is discontinued. If the Company discontinues a part of the Plan (e.g., through a plan amendment that excludes a formerly eligible unit of employees constituting 20% or more of the workforce), you will be fully vested in your account if you are affected by the partial termination.

If the Plan is terminated in whole, the Company will distribute your account to you. Your account will continue to be held in trust until you are eligible to receive a Plan distribution.


Note: Benefits under the Plan are not insured by the federal government. Benefits under certain types of pension plans are insured by the Pension Benefit Guaranty Corporation (PBGC), which is part of the federal government. However, because the Plan maintains individual accounts for each participant, it is not insured by the federal government.

Claim Procedures The Leidos Retirement Programs Department or Vanguard requires that you provide a signed, written statement, along with any supporting materials, in order for you to file a claim for benefits. The following describes the claims process.

All claims should be submitted to: Leidos, Inc. Retirement Programs Department

1750 Presidents Street Reston, VA 20190

Or via email: [email protected]

Review of Your Claim or Application for Benefits Your claim or application for benefits (“claim”) must be in writing and any supporting materials must be attached for the Committee’s review and it must be signed by you and, if requested by the Committee, your spouse. In the case of a death benefit, the statement must be signed by your Beneficiary or your legal representative. The Committee reserves the right to require that you or your Beneficiary furnish proof of age prior to processing the claim. Your claim will be reviewed and either accepted or denied by an authorized representative of the Company within 90 days following its receipt. However, if it is determined that special circumstances require an extension of time, then up to 180 days may be used to decide your claim. You will be informed of the extension and the reasons for the extension before the expiration of the original 90-day period.

If Your Claim Is Denied In the event your claim is denied, in whole or in part, an authorized representative of the Company will notify you in writing of the denial and of your right to a review by the Committee. This notice will provide you with all of the following information:

The specific reasons for the denial Specific references to the Plan provisions on which the denial is based A description of any additional material or information necessary for you to perfect your

application An explanation of why that material or information is necessary An explanation of the Plan’s claim review procedures A statement of your right to bring a civil action under ERISA Section 502(a)


At your request, you will be provided with reasonable access to, and copies free of charge of all documents, records and other information relevant to your claim for benefits, including but not limited to any information relied upon in making the benefit determination, any information submitted, considered or generated while making the benefit determination, and any statement of policy or guidance concerning the denied benefit, even if it was not relied upon.

Appealing Your Claim Denial If your claim is denied in whole or in part, you or your duly authorized representative may appeal the denial to the Committee for a review of the decision. You may make this appeal by submitting to the Committee within 65 days after you received written notice of the denial of your claim, a written statement:

Requesting a review of your application for benefits by the Committee Setting forth all of the grounds upon which your request for review is based and any facts

in support of your claim Setting forth any issue or comments which you think should be considered

All of the above will be taken into account even if it was not submitted as part of your initial claim. The Committee will meet as often as is necessary to review appeals of claim denials submitted to it. The Committee will act upon your application within 60 days after receipt of your request for review by the Committee. However, if the Committee determines that special circumstances require an extension of time, then up to 120 days may be used to decide the review of your denied claim. You will be informed of the extension and the reason for the extension before the expiration of the original 60-day period.

The Committee shall make a full and fair review of your application for benefits and any written materials submitted by you to the Committee in connection with the application. The Committee may require you to submit such additional facts, documents or other evidence as the Committee, in its sole discretion, deems necessary or advisable in making the review. Under the Plan, the Committee is provided the broadest possible discretion to determine factual issues and to interpret the Plan’s provisions. Committee decisions shall be final and binding.

All appeals should be sent to: Leidos, Inc. Retirement Programs Department

1750 Presidents Street Reston, VA 20190

Important: If you appeal a claim decision, you have 180 days after the Committee provides a written notice of the denial of your appeal by the Committee to bring a civil action in court. After that time, if you do file a civil action, the court may dismiss your claim. Fees and Expenses There are costs associated with managing investments and administering 401(k). Investments in 401(k) plans generally include investment management fees and certain fixed costs of investment, as well as costs associated with administering the Plan. Certain costs associated


Remember that Leidoscontinues to pay some of the Plan’s expenses, such as audit and consulting fees, which are not charged to participants.

with the Plan are paid by Leidos and certain costs are paid by Plan participants, both directly and indirectly. Fees charged by mutual funds is one example of an indirect cost paid by Plan participants. Mutual funds charge fees for the management of assets through an expense ratio, which is expressed as a percentage of the dollars invested in the fund. A fund’s expense ratio reduces your rate of return because the fees are deducted from the fund’s assets before determining its overall performance.

You can access expense ratio information for the investments offered in the Plan by viewing their fact sheet or Morningstar® Investment Profile™. These reports are available on the Leidos Online Retirement Guide (www.vanguard.com/leidos for non-bargained employees or www.vanguard.com/leidosbargained for bargained employees). To view these reports, select Your Plan’s features and then Your Plan’s investment options. Choose from Target Retirement Trusts, Core Investment Options, or Supplemental Investment Options to find the investment you wish to research.

In addition to investment management fees, a quarterly administration fee of $7.75 is charged to Plan participants in order to pay administration expenses of operating the Plan. These administration expenses include, among others, expenses related to the call center and recordkeeping. These fees are deducted directly from your Plan account and will be reflected on your quarterly Plan statement. The administration fee is subject to change as necessary.

Plan Administration The Company is the Plan Administrator of the Plan. The Committee, whose members are appointed by the board of directors of the Company, has the responsibility for supervising the administration and operation of the Plan, including the power and authority to:

Allocate fiduciary responsibilities, other than trustee responsibilities, among the named fiduciaries

Designate agents to carry out responsibilities relating to the Plan, other than fiduciary responsibilities

Employ legal, actuarial, medical, accounting, programming and other assistance as the Committee may deem appropriate in carrying out the Plan

Establish rules and regulations for the conduct of the Committee’s business and the administration of the Plan

Administer, interpret, construe and apply the Plan and determine questions relating to eligibility, the amount of any participant’s service and the amount of benefits to which any participant or Beneficiary is entitled

Determine the manner in which the Plan’s assets are disbursed


Direct the Trustee regarding investment of the Plan’s assets, subject to the directions of participants when provided in the Plan

Adopt administrative amendments to the Plan The Leidos Retirement Programs Department is responsible for the day-to-day Plan administration. All contributions are paid to and held by the Trustee, which is currently Vanguard Fiduciary Trust Company. Subject to the direction of the Committee and the participants, the Trustee invests and distributes the funds as provided in the Plan. No funds in the Trust may ever revert to or be used by the Company, except as allowed by federal law. ERISA Rights As a participant in the Plan, you are entitled to certain rights and protections under the Employee Retirement Income Security Act of 1974 (ERISA). ERISA provides that all Plan participants shall be entitled to: Receive information about your plan and benefits o Examine, without charge, at the Plan Administrator’s office and at other specified

locations (such as work sites and union halls), all documents governing the Plan, including insurance contracts and collective bargaining agreements, and a copy of the latest annual report (Form 5500 Series) filed by the Plan with the U.S. Department of Labor and available at the Public Disclosure Room of the Employee Benefits Security Administration.

o Obtain, upon written request to the Plan Administrator, copies of documents governing the operation of the Plan, including insurance contracts and collective bargaining agreements, and copies of the latest annual report (Form 5500 Series) and updated Summary Plan Description. The Plan Administrator may make a reasonable charge for the copies.

o Receive a summary of the Plan’s annual financial report. The Plan Administrator is required by law to furnish each participant with a copy of this summary annual report.

o Obtain a statement telling you whether you have a right to receive a benefit at your Normal Retirement Date (age 59½) and if so, what your benefits would be at your Normal Retirement Date if you stop working under the Plan now. If you do not have a right to a benefit, the statement will tell you how many more years you have to work to get a right to a benefit under the Plan. This statement must be requested in writing and is not required to be given more than once every 12 months. The Plan must provide the statement free of charge.

Prudent actions by plan fiduciaries o In addition to creating rights for Plan participants, ERISA imposes duties upon the people

who are responsible for the operation of the Plan. The people who operate your Plan, called “fiduciaries” of the Plan, have a duty to do so prudently and exclusively in the interest of you and other Plan participants and beneficiaries. No one, including your employer, your union, or any other person, may fire you or otherwise discriminate against you in any way to prevent you from obtaining a benefit or exercising your rights under ERISA.


Enforce your rights o If your claim for a benefit is denied or ignored, in whole or in part, you have a right to know

why this was done, to obtain copies of documents relating to the decision without charge, and to appeal any denial, all within certain time schedules.

o Under ERISA, there are steps you can take to enforce the above rights. For instance, if you request a copy of Plan documents or the latest annual report from the Plan and do not receive them within 30 days, you may file suit in a Federal court. In such a case, the court may require the Plan Administrator to provide the materials and pay you up to $110 a day until you receive the materials, unless the materials were not sent because of reasons beyond the control of the Administrator.

o If you have a claim for benefits which is denied or ignored, in whole or in part, you may file suit in a state or Federal court. In addition, if you disagree with the Plan’s decision or lack thereof concerning the qualified status of a domestic relations order, you may file suit in Federal court.

o If it should happen that Plan fiduciaries misuse the Plan’s money, or if you are discriminated against for asserting your rights, you may seek assistance from the U.S. Department of Labor, or you may file suit in a Federal court. The court will decide who should pay court costs and legal fees. If you are successful, the court may order the person you have sued to pay these costs and fees. If you lose, the court may order you to pay these costs and fees, for example, if it finds your claim is frivolous.

Assistance With Your Questions If you have any questions about your Plan, you should contact Vanguard.

If you have any questions about this statement or about your rights under ERISA, or if you need assistance in obtaining documents, you should contact the nearest office of the Employee Benefits Security Administration, U.S. Department of Labor, listed in your telephone directory or the Division of Technical Assistance 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.

Plan Information Plan Sponsor Leidos, Inc. c/o Retirement Programs Department

1750 Presidents Street, Reston, VA 20190

Email: [email protected]

Internal Revenue Service: Employer ID #95-3630868 Plan #002

Plan Type A defined contribution plan that allows for 401(k) contributions.

Plan Administrator Leidos, Inc. c/o Retirement Programs Department 1750 Presidents Street, Reston, VA 20190

Administration of the Plan Leidos, Inc. is the Plan Administrator and named fiduciary of the Plan. The Plan Administrator has sole and absolute discretionary authority to interpret the terms and provisions of the Plan, and its judgments will be final and binding on all parties. The Plan Administrator may delegate such authority to another person or persons. The Plan Administrator has selected Vanguard as the record keeper and trustee for the Plan to provide various administrative services.

Agent for Service Leidos, Inc. General Counsel Leidos, Inc. Plan Administrator 1750 Presidents Street, Reston, VA 20190

Plan Trustee Vanguard Fiduciary Trust Company (May also be served with legal process) P.O. Box 2900 Valley Forge, PA 19484 Telephone: (610) 669-1000

Record Keeper Plan Numbers 090518 – non bargained employees 094548 – bargained employees

Plan Anniversary Date December 31st of each year. All Plan accounting and records are kept as of this date. The Plan year runs from each January 1 to the next following December 31st

Leidos, Inc. Retirement Plans A list of members can be obtained by contacting: Committee

Leidos, Inc. c/o Retirement Programs Department 1750 Presidents Street, Reston, VA 20190

A complete list of participating employers may be obtained upon written request to the Plan Administrator and is available for examination.



For more information about any fund, including investment objectives, risks, charges, and expenses, call Vanguard at (800) 523-1188 to obtain a prospectus. The prospectus contains this and other important information about the fund. Read and consider the prospectus information carefully before you invest. You can also download Vanguard fund prospectuses at www.vanguard.com/retirement plans. Vanguard Target Retirement Trusts are not mutual funds. They are collective trusts available only to tax-qualified plans and their eligible participants. The collective trust mandates are managed by the Vanguard Fiduciary Trust Company, a subsidiary of The Vanguard Group, Inc. Vanguard, Vanguard.com, and VOICE are trademarks of The Vanguard Group, Inc. Vanguard Marketing Corporation, Distributor of the Vanguard Funds.


Supplement to Prospectus and Summary Plan Description

LEIDOS, INC. RETIREMENT PLAN All references to the “Plan” in this supplement are references to the Le idos, Inc. Retirement Plan described in the Summary Plan Description and Prospectus.

This document constitutes part of a prospectus covering common stock of Leidos Holdings, Inc. and Plan interests that have been registered under the Securities Act of 1933. This portion of the prospectus is not issued by a fiduciary on behalf of the Plan. The Plan’s prospectus (including the Company’s filings with, and disclosures to, the Securities and Exchange Commission), specifically are not incorporated into and are not part of the Summary Plan Description.

Additional Company Information

Where can I get additional information about Leidos? Leidos Holdings, Inc. (the Company) is a reporting company under the Securities Exchange Act of 1934 (the “Exchange Act”) and is required to file periodic and other reports with the SEC. These reports include material financial and other information about the Company, Leidos, Inc., a wholly owned subsidiary of the Company, and the common stock of the Company. (“Leidos Stock”).

Pursuant to the rules and regulations of the SEC, we are allowed to incorporate certain documents into this prospectus by reference. Documents incorporated by reference contain important information that you may want to review and are considered to be a part of this prospectus. The following documents filed by the Company with the SEC are incorporated by reference into and are a part of this prospectus:

(a) Annual Report on Form 10-K for the fiscal year ended December 30, 2016, filed with the

Commission on February 24, 2017

(b) Current Reports on Form 8-K filed with the Commission on January 20, 2017, February 21, 2017, June 8, 2017, June 28, 2017 and August 17, 2017;

(c) Quarterly Report on Form 10-Q filed with the Commission on May 5, 2017, August 4, 2017 and November 11, 2017

(d) Description of the common stock, par value $.0001 per share contained in the Company’s Registration Statement on Form S-4, filed on April 18, 2016, as amended (Registration No. 333-210796); AND

(e) All documents filed by the Company with the SEC (other than, in each case, documents deemed

to have been furnished and not filed in accordance with Commission rules) pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus (but before the Company files a post-effective amendment indicating that all securities offered by this prospectus


have been sold or that the Company has de-registered all securities remaining unsold) will be deemed to be incorporated by reference into this prospectus (and such documents will be a part of this prospectus) from the date that such documents are filed with the SEC. These documents generally include the Company’s annual, quarterly, and current financial and other reports filed with the SEC.

You can inspect and copy these documents and other information about the Company and the Leidos Stock as described below. For purposes of this prospectus, any statement contained in this prospectus or in any other document all or a part of which is incorporated (or deemed to be incorporated) by reference into this prospectus, will be deemed to be modified or superseded to the extent that more current information is provided in (a) this prospectus, or (b) in any other document filed by the Company with the SEC after the date of this prospectus. Any statement that is modified or superseded will not be deemed to constitute a part of this prospectus, except to the extent that it is so modified or amended. Where can I get the Company’s reports and other information? This prospectus constitutes a part of a registration statement (the “Registration Statement”) registering shares of common stock of Leidos Holdings, Inc. under the Securities Act of 1933, as amended (the “Securities Act”) that may be delivered under the Plan. As permitted by the rules and regulations of the SEC, not all of the information provided in the Registration Statement is contained in this prospectus. For more information regarding Leidos Holdings, Inc. and the Leidos Stock, reference is made to the Registration Statement and the documents incorporated into this prospectus by reference (which are identified above). Copies of the Registration Statement the documents which are incorporated into this Prospectus, and other information filed by the Company with the SEC is available through the SEC’s website at http://www.sec.gov. The SEC makes all electronic fillings of periodic reports and registration statements publicly available on the Internet. You may also obtain without charge, upon oral or written request, a copy of the Registration Statement and any document incorporated by reference into this prospectus (except exhibits unless the exhibit you desire has been incorporated by reference in the information incorporated by reference into this prospectus) or any other report or document required to be given to you under SEC Rule 428(b). Please mail your written request to:

Leidos Holdings, Inc. 1750 Presidents Street, Reston, VA 20190 Attention: Corporate Secretary

Telephone requests may be directed to Leidos Holdings, Inc.’s Corporate Secretary at 571-526-6000. You should rely only on the information in or incorporated by reference into this Prospectus and Summary Plan Description. No one has been authorized to provide you with different information. Plan Account Information Where can I get additional information about my Plan account? You can keep track of your account value and investment options through Vanguard’s website at www.vanguard.com/retirementplans. You can also reach Vanguard by telephone at (800) 523-1188.


In addition, a statement of your account value will be provided to you each quarter. Investment Alternatives Under The Plan Each of the Plan’s investment funds offers different opportunities and levels of risk. Your choices should be made carefully on the basis of your personal financial goals. When making investment decisions you should consider how investments in the Plan, when combined with your other investments, fit into your overall investment strategy. You should consider a number of factors, including your tolerance for risk, your time horizon to retirement, and your other investments, as well as the concepts of diversification and asset allocation. You may want to consult with a financial advisor to help you make your investment elections. As of the date of this supplement, the following investment options were offered under the Plan:

• Vanguard Target Retirement Income Trust Select • Vanguard Target Retirement 2015 Trust Select • Vanguard Target Retirement 2020 Trust Select • Vanguard Target Retirement 2025 Trust Select • Vanguard Target Retirement 2030 Trust Select • Vanguard Target Retirement 2035 Trust Select • Vanguard Target Retirement 2040 Trust Select • Vanguard Target Retirement 2045 Trust Select • Vanguard Target Retirement 2050 Trust Select • Vanguard Target Retirement 2055 Trust Select • Vanguard Target Retirement 2060 Trust Select • Vanguard Target Retirement 2065 Trust Select • Leidos Stable Value Fund • Loomis Sayles Core Plus Fixed Income Trust Class D • Vanguard Institutional Total Bond Market Index Trust • Dodge & Cox Stock Fund • Vanguard Institutional 500 Index Trust • Vanguard Institutional Extended Market Index Trust • Vanguard Institutional Total International Stock Market Index Trust • Vanguard International Growth Fund Admiral Shares • Wellington Trust TIPS Portfolio • T.Rowe Price Small & Mid-Cap Core Trust; Class D • T.Rowe Price U.S. Large Cap Growth • Leidos Stock Funds*

*There are two Leidos Stock Funds: the Leidos Common Stock Fund and the Leidos Closed Stock Fund. The Leidos Closed Stock Fund is closed to new investments.

A brief description of the funds, along with certain historical information concerning the past performance of the funds is included in the Your Investment Options at a Glance document attached to this supplement. As with any investment, there are risks involved with investing in the above-mentioned funds. Each investment fund offers its own risk and potential return. No assurances can be given that investment losses will not occur in connection with any of the funds. The Company cannot, and does not, make any specific investment recommendations, nor does it guarantee


participants safety against investment losses. None of the above-mentioned funds are insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC), the Pension Benefit Guaranty Corporation (PBGC) or any other government agency, nor are they guaranteed by Vanguard or Leidos. The Company has not verified the accuracy or completeness of the information contain in the Your Investment Options at a Glance document attached hereto, and makes no representations with respect to the ability of the funds to satisfy their objectives, the achievement of any particular investment returns, or any other aspect of the funds. The Plan is intended to constitute a plan described in Section 404(c) of the Employee Retirement Income Security Act of 1974 (ERISA) and Title 29 of the Code of Federal Regulations Section 2550.404c-l. Under those provisions, fiduciaries of the Plan (e.g., the Leidos, Inc. Retirement Plans Committee) may be relieved of liability for any losses which are the direct and necessary result of investment directions given by you as a Plan participant or beneficiary. Participants are provided with detailed information regarding the current investment alternatives available to them. It is your responsibility to make an informed election from among the available options. Information on the particular investment alternatives is available from the Leidos Retirement Programs Department or from Vanguard by calling (800) 523-1188 or online (www.vanguard.com/retirementplans). Tax Considerations Because the Plan is intended to be a tax-qualified plan under Sections 401(a) and 401(k) of the Internal Revenue Code, participants gain certain income tax advantages during participation and, in some cases, when funds are distributed. As discussed below, the tax consequences of making employee contributions differ depending on whether they are pre-tax traditional contributions, after-tax Roth 401(k) contributions, or traditional after-tax contributions (i.e., non-Roth, after-tax contributions). You are not subject to federal income taxation on your pre-tax traditional employee contributions or the Company’s matching contributions until a distribution or withdrawal occurs. After-tax Roth 401(k) contributions and traditional after-tax contributions are subject to federal income tax when made. Employee contributions (both traditional and Roth 401(k)), as well as traditional after-tax contributions, are subject to FICA tax (Social Security and Medicare) in the year of contribution. The Company also receives a deduction for contributions (within certain limits) made to the Plan. The following is a summary of the federal income tax consequences of participation in the Plan under current U.S. federal tax law. State and local taxes, as well as estate and gift taxes, are beyond the scope of this summary and are not discussed herein. Because tax consequences vary depending on such factors as age, marital status, other income and method or methods of distribution, you are urged to consult a qualified tax advisor concerning your participation in the Plan. What are the tax consequences of a withdrawal or distribution of Plan benefits? Withdrawals or distributions from the Plan (other than amounts attributable to: (1) traditional after-tax contributions, but not related earnings, and (2) Roth 401(k) contributions and related earnings) are generally subject to tax as ordinary income at the time you receive them. This rule applies to distributions of your pre-tax contributions and contributions by the Company and any investment earnings (other than earnings attributable to Roth 401(k) contributions).


The tax consequences of a withdrawal or distribution attributable to Roth 401(k) contributions are discussed in a separate answer below. Traditional after-tax contributions and any historical non-Roth after-tax contributions will not be taxed when they are withdrawn, but the earnings thereon will be subject to tax as ordinary income when withdrawn. To discourage early withdrawal, the law states that if you receive a withdrawal or distribution before age 59½, you generally must pay an additional federal income tax over and above the regular federal income tax due. This additional tax is equal to 10% of the taxable income portion of your withdrawal or distribution. The additional 10% tax is not imposed (1) if you are age 59½, (55 if you have terminated employment from the Company as described below) or older when you receive the withdrawal or distribution; (2) to the extent you incur an unreimbursed medical expense allowable as a federal income tax deduction (whether or not you itemize); (3) if you “rollover” the taxable amount to an individual retirement account (an “IRA”) or another qualified retirement plan within the appropriate amount of time; (4) if your distribution is made after termination of employment and you are age 55 or older in the calendar year of your termination; (5) if you are disabled within the meaning of Section 72(m)(7) of the Internal Revenue Code; (6) if your distribution is due to death, in which case your beneficiary is exempt from the tax; or (7) with respect to qualifying dividends on your investment in the Leidos Stock Funds that you elect to receive in cash. Consult with your tax professional concerning any additional penalties for early distributions under applicable state law. For example, California imposes a 2.5% penalty in addition to the 10% penalty under federal law. Are taxes withheld when Plan benefits are distributed? A withdrawal or distribution is automatically subject to federal tax withholding equal to 20% of the taxable amount, unless you direct the Plan to make a “direct rollover,” as described below. Hardship withdrawals also are subject to withholding because they are not eligible to be “rolled over.” It is important to note that in many cases the amount withheld may not cover the actual tax due. You will be responsible for paying any tax due that is not withheld. Please see the discussion below concerning distributions in the form of Leidos common stock for a special withholding rule. How are distributions taxed following a termination of employment? A withdrawal or distribution from the Plan (other than amounts attributable to Roth 401(k) contributions and traditional after-tax contributions) is taxed as ordinary income unless it qualifies for special tax “averaging.” Ten-year averaging is available to certain participants who reached age 50 before January 1, 1986. For more information on tax averaging and whether or not it would be available and beneficial to you, contact your tax professional. Notwithstanding the foregoing, earnings on traditional after-tax contributions are subject to taxation upon withdrawal or distribution from the Plan. What are the tax consequences of making a “rollover distribution” from the Plan? For withdrawals or distributions other than amounts attributable to Roth 401(k) contributions, if you make a “rollover” into an IRA or another qualified plan which accepts rollovers, you will defer paying tax until you make a withdrawal from the IRA or new plan. (Rollovers of amounts attributable to Roth 401(k) contributions are discussed in a separate answer below.) You may generally rollover any Plan


distribution into an IRA or another qualified retirement plan that accepts rollover contributions within 60 days following receipt of your withdrawal. Although you will not be required to currently pay tax on the portion of the withdrawal which is rolled over, income tax withholding will apply unless you make a “direct rollover” as discussed below. You will be taxed when you make a withdrawal from the IRA or new plan. Subsequent withdrawals from the Plan will not be eligible for 10 year averaging. A portion of the amount which is paid to you because you have attained age 72 (or age 70½ if you reached age 70½ prior to January 1, 2020) is not eligible to be rolled over. In addition, hardship withdrawals may not be rolled over. You will be able to accomplish a rollover by directing the Plan to make a “direct rollover” on your behalf. A direct rollover may be made to an IRA or another defined contribution plan which accepts such transfers. An advantage of the direct rollover is that no federal tax withholding is required if the direct rollover is made. For all other tax purposes, the direct rollover is treated the same as a normal rollover. If you are eligible to establish a Roth IRA, then you are permitted to make a rollover to a Roth IRA. Such a rollover can include amounts attributable to Company contributions and traditional pre-tax employee contributions. However, if you make such a rollover, the distribution will be taxable income to you. In other words, the tax deferral available upon a rollover to a traditional IRA is not available for a rollover to a Roth IRA. However, the 10% additional tax that generally applies if you receive a distribution from the Plan before age 59½ does not apply if you rollover the distribution to a Roth IRA. You should consult your tax advisor concerning your eligibility to establish a Roth IRA and its tax consequences. (Rollovers of amounts attributable to Roth 401(k) contributions are discussed in a separate answer below.) What are the tax consequences of a distribution in the form of Leidos Stock? If you receive a lump sum distribution from the Plan, your distribution includes shares of Leidos common stock, and you elect to not roll over the stock portion of the distribution, then in the year the stock is distributed, and the distribution meets specific IRS requirements, you are required to recognize only the Plan’s cost of the stock as ordinary income. For tax purposes, the Plan’s cost of the stock is known as the “basis” of the stock. Upon distribution, the Plan’s basis will become your basis in the stock. This means that it will be used to calculate your capital gain (or loss) when you ultimately sell the stock. If you don’t roll over your lump sum stock distribution, and the distribution meets specific IRS requirements, then you are subject to capital gains when you eventually sell the stock. There are two components to the gain (or loss) in the value of the stock that you sell. First, the difference in value between your basis in the stock and the stock’s value at the time it was distributed to you will be taxed. This amount will be taxed as long-term capital gain (or loss) in the year you sell your stock. Second, the difference (if any) between the stock’s value at the time it was distributed and its value at the time it was sold by you is also subject to tax. If you hold the stock for less than one year, this amount will be treated as short-term capital gain (or loss). If you hold the stock for one year or more, this amount will be treated as long-term capital gain (or loss). There are special withholding rules if you take your distribution in the form of Leidos common stock. If you make a direct rollover of your stock, then there is no withholding required (the same as for a cash distribution). However, if you do not roll over a stock distribution, then the 20% withholding is only taken on the basis of the stock.


What are the tax consequences of a withdrawal or distribution of Plan benefits attributable to Roth 401(k) contributions? If a withdrawal or distribution attributable to Roth 401(k) contributions is a “qualified distribution,” then the withdrawal or distribution is not subject to federal income taxes. A distribution is a “qualified distribution” only if it is made both (i) after you have completed at least five years of participation in the Roth 401(k) feature of the Plan, and (ii) after you reach age 59½ or on account of your death or disability. For this purpose, the five-year period starts on the first day of the first year in which you make a Roth 401(k) contribution under the Plan. For example, if you make your first Roth 401(k) contribution in April 2021, the five-year period starts on January 1, 2021. If a withdrawal of distribution attributable to Roth 401(k) contributions is not a “qualified distribution,” then the portion of the withdrawal or distribution that represents investment earnings is subject to federal income taxes. In addition, if you are under 59½ when the distribution is made, the portion that represents investment earnings is subject to the additional 10% income tax discussed above, unless one of the exceptions discussed above applies. However, the portion of the withdrawal or distribution that represents your after-tax Roth 401(k) contributions is not subject to federal income taxation or the additional 10% tax. If you receive a lump sum distribution that includes shares of Leidos common stock, and the distribution is not a “qualified distribution,” then rules discussed above (concerning unrealized appreciation and capital gains) that apply to non-Roth 401(k) amounts apply to the distribution. If you receive any “qualified distribution” that includes shares of Leidos stock, your tax basis in the shares is their fair market value at the time of distribution. What are the tax consequences of making a “rollover distribution” of Plan benefits attributable to Roth 401(k) contributions? If you make a “rollover” of benefits attributable to Roth 401(k) contributions into a Roth IRA or Roth 401(k) account in another qualified plan which accepts rollovers, the distribution is not taxable, regardless of whether it is a “qualified distribution.” The tax treatment of a subsequent withdrawal or distribution from the Roth IRA or other qualified plan is subject to the rules concerning qualified distributions, as discussed above. Benefits attributable to Roth 401(k) contributions may not be rolled over to a non-Roth IRA or another qualified plan that does not have a Roth 401(k) account. If your rollover contribution is a direct rollover to a Roth 401(k) account in another qualified plan, then the period you completed under the Plan counts towards the five-year period needed for a “qualified distribution.” However, if your rollover contribution to a Roth 401(k) account in another qualified plan is an indirect rollover, then you must separately satisfy the five-year requirement in such other plan. If your rollover contribution is to a Roth IRA, then you must separately satisfy the five-year requirement for qualified distributions in your Roth IRA. In other words, your period of participation in the Roth 401(k) feature of the Plan cannot be used to satisfy the five-year requirement for qualified distributions from a Roth IRA. Although the Summary Plan Description and Prospectus describes many of the principal features of the Plan, it is only a summary. The complete provisions of the Plan are set forth in


the Plan document which is available for your review upon request. If there is any inconsistency between the Summary Plan Description and Prospectus or any other communication regarding the Plan and the Plan document itself, the Plan document will govern.


Your Investment Options at a Glance LEIDOS, INC. RETIREMENT PLAN (090518) LEIDOS, INC. RETIREMENT PLAN (BARGAINED EMPLOYEES ACCOUNT) (094548)

The plan offers the following diversified lineup of investment options. Diversification does not ensure a profit or protect against a loss.

Log on to your account at vanguard.com/retirementplans or review your quarterly account statement for easy access to the most up-to-date information about each investment, including investment strategy, performance data, and fees. If you cannot access the investment information online or have questions about your plan’s investment lineup, call Vanguard Participant Services at 800-523-1188.

Note: If investment changes are pending, they will not be reflected on this document or online. After the changes go into effect, log on to your account at vanguard.com/retirementplans to view the up-to-date investment lineup. To register for online access, you'll need your six-digit plan number, which can be found at the top of this document.

Target-date investments

Investment name Fund number

Vanguard Target Retirement 2015 Trust Select 1675











Vanguard Target Retirement Income Trust Select 1686


Short-term reserves


Leidos Stable Value Fund 5925

Bonds


Loomis Sayles Core Plus Fixed Income Trust; Class D 6339

Vanguard Institutional Total Bond Market Index Trust 5797

Wellington Trust TIPS Portfolio 3247

Domestic stocks


Dodge & Cox Stock Fund 0292

Leidos Common Stock Fund 4355

T.Rowe Price Small & Mid-Cap Core Trust; Class D 7603

T.Rowe Price U.S. Large Cap Growth Fund 8329

Vanguard Institutional 500 Index Trust 5796

Vanguard Institutional Extended Market Index Trust 5798

International investments


Vanguard International Growth Fund Admiral™ Shares 0581

Vanguard Institutional Total International Stock Market Index Trust 7585


A note about risk Whenever you invest, there’s a chance you could lose the money. Investments in target-date investments are subject to the risks of their underlying funds. The year in the investment name refers to the approximate year (the target date) when an investor would retire and leave the workforce. The investment will gradually shift its emphasis from more aggressive investments to more conservative ones based on its target date. An investment in a target-date investment is not guaranteed at any time, including on or after the target date. Bond funds are made up of IOUs, primarily from companies or governments. These funds risk losing value if the debt isn’t repaid on time. Also, bond prices can drop when interest rates rise or the issuer’s reputation suffers. U.S. Treasury investments and some U.S. government agency bonds are backed by the government, so it’s highly likely that payments will be made on time. But their prices can still fall when interest rates go up. Vanguard Total International Bond Index Fund has a risk tied to a financial technique called currency hedging. Hedging helps protect the fund when foreign currency exchange rates are unfavorable. However, the fund may miss out on gains when exchange rates are favorable. Hedging also costs the fund money. PIMCO Total Return Fund uses financial contracts called derivatives to try to reduce risk and improve returns. But derivatives have risks of their own. These include the chance that the fund manager will misjudge the direction of the market or that the fund can’t exit the contracts at the best time. It’s possible for the fund to lose all of the money invested in derivatives—and more. High-yield (“junk”) bonds come from borrowers more likely to default on loans than borrowers with better credit ratings. These bonds tend to pay higher interest rates to offset their higher risk. Small- and mid-cap funds are made up of the stocks of small and medium-sized companies. These companies have fewer financial resources than larger companies. Because of that, their stock prices can be more affected by swings in the economy. Non-U.S. stocks or bonds have risks tied to the political and economic stability of their country or region. And if the value of the foreign currency falls, the value of the stocks or bonds would also fall. In emerging markets (less developed countries), these risks may be even greater. Funds that focus on a narrow part of the economy—for example, real estate or health care—can fluctuate sharply in price. This makes them riskier than broadly based stock funds. The performance of a company stock fund depends on the price of a single stock, which can move up or down dramatically. So this type of fund can be riskier than a stock mutual fund, which may own hundreds or thousands of stocks. ESG (environmental/social/governance) funds are subject to ESG investment risk, which is the chance that the stocks screened by the index sponsor for ESG criteria generally will underperform the stock market as a whole or that the particular stocks selected will, in the aggregate, trail returns of other funds screened for ESG criteria.

Supplement to Prospectus and Summary Plan Description | 50

Connect with Vanguard® vanguard.com/retirementplans > 800-523-1188

For more information about any fund, including investment objectives, risks, charges, and expenses, call Vanguard at 800- 523-1188 to obtain a prospectus or, if available, a summary prospectus. The prospectus contains this and other important information about the fund. Read and consider the prospectus information carefully before you invest. You can also download Vanguard fund prospectuses at vanguard.com.

An investment in a stable value investment is neither insured nor guaranteed by the U.S. government. There is no assurance that the investment will be able to maintain a stable net asset value, and it is possible to lose money by investing in the investment.

Vanguard trusts are not mutual funds. They are collective trusts available only to tax-qualified plans and their eligible participants. Investment objectives, risks, charges, expenses, and other important information should be considered carefully before investing. The collective trust mandates are managed by Vanguard Fiduciary Trust Company, a wholly owned subsidiary of The Vanguard Group, Inc.

Collective trusts and separately managed accounts (SMAs) are not mutual funds. These investments are available only to tax-qualified plans and their eligible participants. Investment objectives, risks, charges, expenses, and other important information should be considered carefully before investing.

Participant Education

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Valley Forge, PA 19482-2900

© 2021 The Vanguard Group, Inc. All rights reserved. Vanguard Marketing Corporation, Distributor of the Vanguard Funds.

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