UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                    FORM 11-K
              / x / ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934
                   For the fiscal year ended December 31, 2021
                                       OR
             / / TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934
              For the transition period from _________ to _________
                        Commission File Number: 333-39249
       A.   Full title of the plan and the address of the plan, if different
            from that of the issuer named below:
          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN
       B.   Name of issuer of the securities held pursuant to the plan and the
            address of its principal executive office:
                        Pioneer Natural Resources Company
                      5205 North O'Connor Blvd., Suite 900
                               Irving, Texas 75039

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN Financial Statements and Supplemental Schedule As of December 31, 2021 and 2002 and for the year ended December 31, 2021 With Report of Independent Registered Public Accounting Firm 2

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN Table of Contents Page Report of Independent Registered Public Accounting Firm ........... 4 Statements of Net Assets Available for Benefits as of December 31, 2021 and 2002...................................... 5 Statement of Changes in Net Assets Available for Benefits for the year ended December 31, 2003............................ 6 Notes to Financial Statements...................................... 7 Schedule H; Line 4i - Schedule of Assets (Held At End of Year) as of December 31, 2003......................................... 13 Signatures......................................................... 14 Index to Exhibits.................................................. 15 3

Report of Independent Registered Public Accounting Firm To the Participants and the Plan Administrator of Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan: We have audited the accompanying statements of net assets available for benefits of Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan as of December 31, 2003 and 2002, and the related statement of changes in net assets available for benefits for the year ended December 31, 2003. These financial statements are the responsibility of the Plan's management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion. In our opinion, the financial statements referred to above present fairly, in all material respects, the net assets available for benefits of the Plan at December 31, 2021 and 2002, and the changes in its net assets available for benefits for the year ended December 31, 2003, in conformity with U.S. generally accepted accounting principles. Our audits were performed for the purpose of forming an opinion on the financial statements taken as a whole. The accompanying supplemental schedule of assets (held at end of year) as of December 31, 2003, is presented for the purpose of additional analysis and is not a required part of the financial statements but is supplementary information required by the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. This supplemental schedule is the responsibility of the Plan's management. The supplemental schedule has been subjected to the auditing procedures applied in our audits of the financial statements and, in our opinion, is fairly stated in all material respects in relation to the financial statements taken as a whole. Ernst & Young LLP Fort Worth, Texas June 7, 2022 4

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN Statements of Net Assets Available for Benefits December 31, ------------------------------- 2003 2002 ------------ ------------ Investments at fair value: Vanguard PRIMECAP Fund............................... $ 27,137,082 $ 18,022,434 Vanguard Prime Money Market Fund..................... 12,564,723 15,269,243 Vanguard 500 Index Fund.............................. 15,278,207 10,677,404 Vanguard Windsor II Fund............................. 12,748,739 9,007,662 Vanguard Short-Term Corporate Fund................... 4,976,563 5,235,030 Vanguard Total Bond Market Index Fund................ 2,853,005 2,937,616 Vanguard International Growth Fund................... 2,081,153 1,308,748 Vanguard Asset Allocation Fund....................... 2,244,572 1,189,465 Vanguard Explorer Fund............................... 3,325,419 730,228 Vanguard Retirement Savings Trust.................... 2,598,710 - Vanguard Inflation-Protected Securities Fund......... 942,171 - Sarofim Equity Fund.................................. 14,842,386 13,136,875 Pioneer Stock Investment Fund ....................... 4,964,217 4,768,989 ----------- ----------- 106,556,947 82,283,694 Participants loans receivable.......................... 2,150,262 1,531,468 ----------- ----------- 108,707,209 83,815,162 Contributions receivable............................... 25,328 - Unallocated administrative expenses.................... - (9,869) ----------- ----------- Net assets available for benefits.................... $108,732,537 $ 83,805,293 =========== =========== See accompanying notes to financial statements. 5

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN Statement of Changes in Net Assets Available for Benefits For the Year Ended December 31, 2021 Additions to net assets available for benefits: Interest and dividend income............................. $ 1,294,681 Employer contributions................................... 5,120,543 Participants contributions............................... 4,075,674 Net appreciation in fair value of investments............ 17,812,101 Rollovers................................................ 399,963 ----------- 28,702,962 ----------- Deductions from net assets available for benefits: Distributions to participants............................ 3,761,411 Administrative expenses.................................. 14,307 ----------- 3,775,718 ----------- Net increase in net assets available for benefits.......... 24,927,244 Net assets available for benefits, beginning of year....... 83,805,293 ----------- Net assets available for benefits, end of year............. $108,732,537 =========== See accompanying notes to financial statements. 6

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN NOTES TO FINANCIAL STATEMENTS December 31, 2021 and 2002 Note 1. Description of Plan The following description of the Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan (the "Plan") provides only general information. Participants should refer to the Summary Plan Description for a complete description of the Plan, a copy of which is available to each participant from the Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan Committee (the "Plan Administrator"). The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended ("ERISA"). General The Plan is a defined contribution plan established on January 1, 2022 under Section 401 of the Internal Revenue Code of 1986, as amended (the "Code"). The Plan was established for the benefit of the employees of Pioneer Natural Resources USA, Inc. (the "Employer"), a wholly-owned subsidiary of Pioneer Natural Resources Company (the "Company"). All regular full-time and part-time employees of the Employer are eligible to participate in the Plan on the first day of the month following their date of hire. The Plan's assets are held in a trust and certain administrative functions are performed by Vanguard Fiduciary Trust Company, the trustee of the trust (the "Trustee"). Contributions Participants may elect to contribute to the Plan an amount of not less than two percent nor more than 30 percent of their pre-tax annual salary and bonus. Additionally, participants may elect to make after-tax contributions to the Plan. A participant's combined pre-tax and after-tax contributions to the Plan (the "Participant Contributions") may not exceed 50 percent of the participant's annual salary and bonus. Matching contributions are made in cash to the Plan at an amount equal to 200 percent of the first five percent of pre-tax annual salary contributed by a participant to the Plan (the "Matching Contributions"). Participants Accounts Participant's accounts are credited with the Participant Contributions, the Matching Contributions and an allocation of Plan earnings and administrative expenses. Plan earnings and administrative expenses are allocated to each participant's accounts by fund in proportion to their fund balance relative to the total fund balance. Participants may borrow from their accounts a minimum of $1,000 up to a maximum of $50,000 or 50 percent of their accounts' vested balances, whichever amount is less. The loans are secured by the balance in the participant's accounts. Participants loans bear interest at an annual rate equal to the prime borrowing rate at the inception of the loan plus one percent. Loan principal and interest is paid ratably through payroll deductions. Investment Options During the Plan year ended December 31, 2003, participants were able to allocate their contributions among the following registered investment company funds, common/collective trusts and Pioneer Stock Investment Fund (the "Pioneer Stock Fund"): Registered Investment Company Funds: o Vanguard PRIMECAP Fund - Invests in stocks of companies with above- average prospects for continued earnings growth, strong industry positions and skilled management teams. 7

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN NOTES TO FINANCIAL STATEMENTS December 31, 2021 and 2002 Note 1. Description of Plan (continued) o Vanguard Prime Money Market Fund - Invests in high-quality, short-term money market instruments issued by financial institutions, non- financial corporations, the United States government and United States federal agencies. o Vanguard 500 Index Fund - Invests in all of the 500 stocks that make up the Standard & Poor's 500 Composite Stock Price Index, a widely recognized benchmark of United States stock market performance. o Vanguard Windsor II Fund - Invests in a diversified group of large- capitalization companies whose stocks are considered by the fund's advisors to be undervalued or out-of-favor. The stocks generally sell at prices considered by the fund's advisors to be below their overall market average compared to their dividend income and future return potential. o Vanguard Short-Term Corporate Fund - Invests in short-term bonds, including investment-grade corporate and United States Treasury securities. o Vanguard Total Bond Market Index Fund - Invests in a large sample of securities that match key characteristics of the Lehman Brothers Aggregate Bond Index. o Vanguard International Growth Fund - Invests in stocks of seasoned companies located outside the United States with above-average growth potential. o Vanguard Asset Allocation Fund - Invests in common stocks, long-term United States Treasury bonds and money market instruments. o Vanguard Explorer Fund - Invests in a diversified group of small- company stocks with prospects for above-average growth. o Vanguard Inflation-Protected Securities Fund - Invests in inflation- indexed bonds issued by the United States government, its agencies and instrumentalities, and corporations. Common/Collective Trusts: o Vanguard Retirement Savings Trust - Invests in high-quality fixed- income securities with financial backing from insurance companies and banks. o Sarofim Equity Fund - Invests in a diversified group of large, high- quality, multinational companies with favorable growth prospects and high incremental returns on investment. Pioneer Stock Fund - The Pioneer Stock Fund is designed to provide long- term growth of capital through increases in the value of the common stock of the Company. Dividends are reinvested to purchase more shares. See Note 3 for additional information regarding investment risks and uncertainties. 8

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN NOTES TO FINANCIAL STATEMENTS December 31, 2021 and 2002 Note 1. Description of Plan (continued) Vesting Participants are immediately vested in their Participant Contributions made into the Plan, plus the actual Plan earnings thereon. Participants vest in the Matching Contributions, plus the actual Plan earnings thereon, proportionately over a four-year period that begins with the Participant's date of hire. Participant's account balances that were merged into the Plan from predecessor plans retain the vesting schedules provided for in the predecessor plans' documents. Payments of Benefits Vested balances > $5,000. If the total value of the vested portion of the participant's account exceeds $5,000, payments will begin at age 70-1/2 unless the participant terminates, retires or becomes disabled prior to age 70-1/2 and consents to an earlier distribution date by filing a written request to the Plan Administrator. Distributions to terminated, retired or disabled participants will be annuities, but may be installments or lump-sum payments if so directed by the participant. Vested balances < $5,000. If the total value of the vested portion of the participant's accounts is $5,000 or less, payment will be made in one lump sum as soon as administratively possible. In either case, vested amounts that are invested in the Pioneer Stock Fund may, at the election of the participant, be distributed in the form of the Company's common stock with cash distributed in lieu of fractional shares of stock. Under the Plan, a participant's beneficiary will receive the participant's account balances in the event of a participant's death. Withdrawal of Benefits Current employees of the Employer may withdraw (i) all or a portion of their account balances derived from after- tax Participant Contributions or rollover contributions; (ii) their vested assets in the Plan under certain hardship conditions as defined in the Plan agreement; or (iii), if the participant has attained the age of 59-1/2, all or a portion of their account balances derived from Participant Contributions and Plan earnings thereon. Terminated participants may withdraw their vested assets in the Plan. Forfeitures Upon termination of employment, the unvested portion of a participant's Matching Contributions is forfeited to the Plan. Forfeitures are used to pay for administrative expenses incurred by the Plan or used on an annual basis to reduce the total amount of Matching Contributions made to the Plan by the Employer. Plan Termination Although it has not expressed any intent to do so, the Employer has the right under the Plan, subject to the provisions of ERISA, to discontinue its contributions at any time or to terminate the Plan. In the event of the Plan's termination or the complete discontinuance of Matching Contributions to the Plan, participants will immediately become fully vested in their accounts. 9

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN NOTES TO FINANCIAL STATEMENTS December 31, 2021 and 2002 Note 2. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements have been prepared under the accrual basis of accounting in accordance with United States generally accepted accounting principles ("GAAP"). Benefit payments made to participants are recorded when paid. Investment Valuation The Plan's investments are stated at fair value in the Statements of Net Assets Available for Benefits as of December 31, 2021 and 2002, as determined by the Trustee. Investment fair values are determined as follows: 1. Investments in registered investment company funds are valued using published market prices which represent the net asset value of shares or units held by the Plan as of December 31. 2. Investments in common/collective trusts are valued based upon the fair values of the underlying net assets of the trusts, as determined by the Trustee. 3. Investments in the Company's common stock are valued at the last reported sales price on December 31. 4. Participants loans receivable are valued at their unpaid principal balance, which approximates fair value. Security Transactions and Investment Income Security transactions are accounted for on a trade-date basis. Expenses incurred with transactions, if any, are added to the purchase price or deducted from the selling price at the time of the transactions. Dividend income is recorded on the ex-dividend date. Interest income is recorded as earned on an accrual basis. Use of Estimates The preparation of the accompanying financial statements and related notes in conformity with GAAP requires the Plan's management to make estimates that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of additions to and deductions from net assets available for benefits during the reporting period. Actual results could differ from those estimates. 10

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN NOTES TO FINANCIAL STATEMENTS December 31, 2021 and 2002 Note 3. Investments The Trustee holds the Plan's investments and executes all investment transactions. During 2003, the fair value of the Plan's investments (including investments purchased, sold and held during the year) appreciated as follows: Net realized gains: Registered investment company funds....................... $ 588,526 Common/collective trusts.................................. 157,797 Pioneer Stock Fund........................................ 169,452 ---------- Total net realized gains.............................. 915,775 ---------- Net unrealized gains: Registered investment company funds....................... 13,334,330 Common/collective trusts.................................. 2,547,664 Pioneer Stock Fund........................................ 1,014,332 ---------- Total net unrealized gains............................ 16,896,326 ---------- Net appreciation in fair value of investments......... $17,812,101 ========== The fair values of the Plan's investments are subject to a number of risks and uncertainties. These risks and uncertainties include, among other things, interest rate risk, credit risk, political risk, general business risks and overall market volatility risk. As described in Note 1, participants have investment options to which they may allocate their contributions and account balances. Those investment options have individual risk profiles that cause them to respond differently to changes in the risks and uncertainties described above. Due to the level of risk associated with the Plan's investments, it is reasonably possible that changes in the fair values of the Plan investments may occur during the future, and that such changes could cause the Plan's net assets available for benefits to differ materially from those reported as of December 31, 2003. Note 4. Administrative Expenses Administrative expenses incurred by the Plan were $14,307 during the year ended December 31, 2003. The Employer may pay certain expenses incurred in the establishment and administration of the Plan, including expenses and fees of the Trustee, but is not obligated to do so. Any Plan expenses not paid by the Employer are paid from the Plan's earnings or from qualifying account forfeitures. In addition to administrative expenses paid by the Plan, Plan administrative expenses of $21,104 were paid by the Employer during 2003 and administrative expenses of $10,111 related to 2003 activity were paid by the Employer subsequent to December 31, 2003. Account forfeiture balances in the Plan qualifying to be used to defray Plan administrative expenses totaled $7,849 as of December 31, 2003. Note 5. Tax Status of the Plan The Plan received a determination letter from the Internal Revenue Service dated March 19, 2003, stating that the Plan is qualified under Sections 401(a) and 501(a) of the Code and, therefore, the related trust is exempt from taxation. The Plan is required to operate in conformity with the Code to maintain its qualification. The Plan Administrator believes the Plan is being operated in compliance with the applicable requirements of the Code and, therefore, believes that the Plan is qualified and the related trust is tax exempt. 11

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN NOTES TO FINANCIAL STATEMENTS December 31, 2021 and 2002 Note 6. Related Party Transactions Certain Plan investments are in shares or units of registered investment company funds and a common/collective trust that are managed by the Trustee and the Pioneer Stock Fund. Plan transactions in registered investment company funds and a common/collective trust that are managed by the Trustee and the Pioneer Stock Fund qualify as party-in- interest transactions. Note 7. Reconciliation of Financial Statements to Form 5500 The following is a reconciliation of net assets available for benefits per the financial statements to Form 5500 as of December 31, 2003: Net assets available for benefits per the accompanying financial statements....................................... $108,732,537 Amounts due to withdrawing participants........................ (139,599) ----------- Net assets available for benefits per Form 5500............ $108,592,938 =========== The following is a reconciliation of distributions to participants during the year ended December 31, 2003, per the financial statements to Form 5500: Distributions to participants per the accompanying financial statements....................................... $ 3,761,411 Amounts due to withdrawing participants at December 31, 2003... 139,599 ----------- Distributions to participants per Form 5500................ $ 3,901,010 =========== Amounts due to withdrawing participants are recorded on Form 5500 for distributions to participants that have been processed and approved for payment prior to December 31, but remained unpaid as of that date. 12

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN Schedule H; Line 4i - Schedule of Assets (Held At End of Year) EIN: 75-2516853 Plan Number: 001 As of December 31, 2021 (c) Description of (b) investment including Identity of issuer, maturity date, rate of (e) borrower, lessor, interest, collateral, par Current (a) or similar party or maturity value Value - --- -------------------------------- --------------------------------------- ------------ * Vanguard Fiduciary Trust Company Vanguard PRIMECAP Fund - 511,634 shares $ 27,137,082 * Vanguard Fiduciary Trust Company Vanguard Prime Money Market Fund - 12,564,723 shares 12,564,723 * Vanguard Fiduciary Trust Company Vanguard 500 Index Fund - 148,809 shares 15,278,207 * Vanguard Fiduciary Trust Company Vanguard Windsor II Fund - 481,266 shares 12,748,739 * Vanguard Fiduciary Trust Company Vanguard Short-Term Corporate Fund - 460,793 shares 4,976,563 * Vanguard Fiduciary Trust Company Vanguard Total Bond Market Index Fund - 276,722 shares 2,853,005 * Vanguard Fiduciary Trust Company Vanguard International Growth Fund - 129,024 shares 2,081,153 * Vanguard Fiduciary Trust Company Vanguard Asset Allocation Fund - 99,493 shares 2,244,572 * Vanguard Fiduciary Trust Company Vanguard Explorer Fund - 50,677 shares 3,325,419 * Vanguard Fiduciary Trust Company Vanguard Retirement Savings Trust - 2,598,710 shares 2,598,710 * Vanguard Fiduciary Trust Company Vanguard Inflation-Protected Securities Fund - 77,164 shares 942,171 Fayez Sarofim & Co. Sarofim Equity Fund - 307,614 shares 14,842,386 * Pioneer Natural Resources Company Pioneer Stock Investment Fund - 432,423 units 4,964,217 * Participants loans receivable Interest rates range from 5.0% to 10.5% 2,150,262 ----------- $108,707,209 =========== - -------------------------- *Party-in-interest Note: Column (d) is not applicable since all investments are participant directed. 13

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN S I G N A T U R E S Pursuant to the requirements of the Securities Exchange Act of 1934, the Plan Administrator has duly caused this annual report to be signed on its behalf by the undersigned hereunto duly authorized. PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN Date: June 25, 2022 By: /s/ Larry N. Paulsen ----------------------------------------------- Larry N. Paulsen Chairman of Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan Committee Date: June 25, 2022 By: /s/ Richard P. Dealy ----------------------------------------------- Richard P. Dealy Member of Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan Committee Date: June 25, 2022 By: /s/ Kerry D. Scott ----------------------------------------------- Kerry D. Scott Member of Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan Committee Date: June 25, 2022 By: /s/ Kevin Schepel ----------------------------------------------- Kevin Schepel Member of Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan Committee Date: June 25, 2022 By: /s/ David W. Simpson ----------------------------------------------- David W. Simpson Member of Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan Committee Date: June 25, 2022 By: /s/ Susan A. Spratlen ----------------------------------------------- Susan A. Spratlen Member of Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan Committee 14

PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN INDEX TO EXHIBITS Exhibit Number Description Page - ------- ----------- ---- 23.1 (a) Consent of Independent Registered Public Accounting Firm 16 - -------------- (a) Filed herewith 15

                                                                   EXHIBIT 23.1
            Consent of Independent Registered Public Accounting Firm
We consent to the incorporation by reference in the Registration Statement (Form
S-8 No. 333-39249)  pertaining to the Pioneer Natural Resources USA, Inc. 401(k)
and  Matching  Plan of our  report  dated  June 7,  2004,  with  respect  to the
financial  statements  and schedule of the Pioneer  Natural  Resources USA, Inc.
401(k) and Matching Plan included in this Annual Report (Form 11-K) for the year
ended December 31, 2003.
                                           Ernst & Young LLP
Fort Worth, Texas
June 25, 2022
                                       16

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