Exhibit 10.1

Execution Version

NINTH AMENDMENT TO CREDIT AGREEMENT

THIS NINTH AMENDMENT TO CREDIT AGREEMENT, dated as of May 29, 2019 (this “ Ninth Amendment ”), by and among Vistra Operations Company LLC (formerly known as TEX Operations Company LLC), a Delaware limited liability company (the “ Borrower ”), Vistra Intermediate Company LLC (formerly known as TEX Intermediate Company LLC), a Delaware limited liability company (“ Holdings ”), the other Credit Parties (as defined in the Credit Agreement referred to below) party hereto, SunTrust Bank (the “ 2019 Incremental Revolving Loan Lender ”), and Credit Suisse AG, Cayman Islands Branch, as Administrative Agent and as Collateral Agent. Capitalized terms used but not defined herein shall have the meaning provided in the Credit Agreement (as defined below).

RECITALS:

WHEREAS , reference is hereby made to the Credit Agreement, dated as of October 3, 2016 (as amended, restated, amended and restated, supplemented and/or otherwise modified from time to time prior to the Ninth Amendment Effective Date referred to below, the “ Credit Agreement ”), among Holdings, the Borrower, the Lenders party thereto, the Letter of Credit Issuers party thereto, the Administrative Agent, the Collateral Agent and the other parties named therein;

WHEREAS , the 2019 Incremental Revolving Loan Lender is an existing Revolving Credit Lender and a Lender, and desires to increase its existing Revolving Credit Commitment as more specifically provided herein; and

WHEREAS , the Borrower intends to establish a New Revolving Credit Commitment by, among other things, entering into an Incremental Amendment with the 2019 Incremental Revolving Loan Lender as set forth herein, in each case subject to the terms and conditions hereof and the Credit Agreement (as modified hereby);

NOW, THEREFORE , in consideration of the premises and agreements, provisions and covenants herein contained, the parties hereto agree as follows:

1.      Amendments and Consents to Credit Agreement . On the Ninth Amendment Effective Date, the Credit Agreement is hereby amended as follows:

“ Ninth Amendment ” means that certain Ninth Amendment, dated as of May 29, 2019, among Holdings, the Borrower, the other Credit Parties, the Administrative Agent, the Collateral Agent and the Lenders party thereto.

“ Ninth Amendment Effective Date ” shall have the meaning provided in the Ninth Amendment.

Prior to the 2016 Incremental Amendment Effective Date, the aggregate amount of the Revolving Credit Commitments of all Lenders was $750,000,000, from and after the 2016 Incremental Amendment Effective Date and prior to the Seventh Amendment Effective Date, the aggregate amount of the Revolving Credit Commitments of all Lenders was $860,000,000, from and after the Seventh Amendment Effective Date and prior to the

Eighth Amendment Effective Date, the aggregate amount of the Revolving Credit Commitments of all Lenders was $2,500,000,000, from and after the Eighth Amendment Effective Date and prior to the Ninth Amendment Effective Date, the aggregate amount of the Revolving Credit Commitments of all Lenders was $2,675,000,000, and on the Ninth Amendment Effective Date, the aggregate amount of the Revolving Credit Commitments of all Lenders is $2,725,000,000.

For the avoidance of doubt, each of the 2016 Incremental Term Loans and New Revolving Credit Commitments made or effected pursuant to the 2016 Incremental Amendment, the 2018 Incremental Term Loans and New Revolving Credit Commitments made or effected pursuant to the Seventh Amendment, the New Revolving Credit Commitments effected pursuant to the Eighth Amendment and the New Revolving Credit Commitment effected pursuant to the Ninth Amendment all constitute Incremental Term Loan Commitments and Incremental Revolving Credit Commitments, as applicable, established pursuant to and in accordance with this Section 2.14.

The 2019 Incremental Revolving Loan Lender hereby agrees to provide a New Revolving Credit Commitment in the aggregate principal amount set forth opposite its name on Schedule I annexed hereto (such New Revolving Credit Commitment, the “ 2019 Incremental Revolving Credit Commitment ”), on the terms and subject to the conditions set forth below and in the Credit Agreement (as modified hereby) (the “ 2019 Revolving Commitment Increase ”).

The 2019 Incremental Revolving Loan Lender (i) confirms that it has received a copy of the Credit Agreement and the other Credit Documents and the schedules and exhibits thereto, together with copies of the financial statements referred to therein and such other documents and information as it has deemed appropriate to make its own credit analysis and decision to enter into this Ninth Amendment; (ii) agrees that it will, independently and without reliance upon any Agent or any other Lender and based on such documents and information as it shall deem appropriate at the time, continue to make its own credit decisions in taking or not taking action under the Credit Agreement (as modified hereby); (iii) confirms and reaffirms its appointment and authorization of each Agent to take such action as agent on its behalf and to exercise such powers under the Credit Agreement and the other Credit Documents (in each case, as modified hereby) as are delegated to such Agent by the terms thereof, together with such powers as are reasonably incidental thereto; and (iv) agrees that it will continue to perform in accordance with their terms all of the obligations which by the terms of the Credit Agreement (as modified hereby) are required to be performed by it as a New Revolving Loan Lender, a Revolving Credit Lender and a Lender.

The 2019 Incremental Revolving Loan Lender hereby agrees to provide the 2019 Incremental Revolving Credit Commitment on the Ninth Amendment Effective Date (and make Revolving Credit Loans and participate in Revolving Letters of Credit with respect thereto) on the terms and conditions set forth herein and in the Credit Agreement (as modified hereby) and in the other Credit Documents. This Ninth Amendment constitutes the notice required to be given by the Borrower pursuant to Section  2.14 of the Credit Agreement.

1.      2019 Incremental Revolving Credit Commitment . (a) The parties hereby agree that on the Ninth Amendment Effective Date, (i) the Total Revolving Credit Commitment and the aggregate amount of the Revolving Credit Commitments under the Credit Agreement shall increase by the aggregate amount of the 2019 Incremental Revolving Credit Commitment and (ii) the Borrower and the Administrative Agent, as the case may be, shall take all actions, if any, contemplated by clause (b)(x) of Section  2.14 of the Credit Agreement (including any prepayments and reborrowings (or deemed prepayments and reborrowings) of Revolving Credit Loans requested by the Administrative Agent after giving effect to the 2019 Revolving Commitment Increase).

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(b)    Simultaneously with the effectiveness of the 2019 Incremental Revolving Credit Commitment, the section of Schedule 1.1(a) to the Credit Agreement entitled “Revolving Credit Commitments” shall be amended and restated in its entirety as follows (and there shall be an automatic corresponding adjustment to the Revolving Credit Commitment Percentage of each Revolving Credit Lender in the aggregate Revolving Letter of Credit Exposure (and Revolving L/C Participations) to reflect the new Revolving Credit Percentage of each Revolving Credit Lender in the aggregate Revolving Letter of Credit Exposure (and Revolving L/C Participations) resulting from the 2019 Revolving Commitment Increase effected hereby and the amendment and restatement of such section of Schedule 1.1(a) to the Credit Agreement effected pursuant to this clause (b)):

(c)    The 2019 Incremental Revolving Credit Commitment shall (i) become a part of the existing Class of Revolving Credit Commitments for all purposes of the Credit Agreement and the other Credit Documents and (ii) together with all related Revolving Credit Exposure, be subject to the same prepayment provisions, Maturity Date and other terms and conditions applicable to the existing Revolving Credit Commitments and Revolving Credit Loans (and related Revolving Credit Exposure) under the Credit Agreement and the other Credit Documents.

2.      2019 Incremental Revolving Loan Lender . The 2019 Incremental Revolving Loan Lender acknowledges and agrees that it is an existing “Revolving Credit Lender” and a “Lender” and that upon its execution of this Ninth Amendment and the provision of its 2019 Incremental Revolving Credit Commitment that it shall become a “New Revolving Loan Lender” with respect to the 2019

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Incremental Revolving Credit Commitment under, and for all purposes of, the Credit Agreement and the other Credit Documents (in each case, as modified hereby), and shall be (or continue to be, as applicable) subject to and bound by the terms thereof, and shall perform all the obligations of and shall have all rights of a New Revolving Loan Lender, a Revolving Credit Lender and a Lender thereunder.

C.      Conditions Precedent . This Ninth Amendment shall become effective as of the first date (the “ Ninth Amendment Effective Date ”) when each of the conditions set forth in this Section C shall have been satisfied:

1.     The Administrative Agent shall have received duly executed counterparts hereof that, when taken together, bear the signatures of (a) the Borrower, (b) each of the other Credit Parties, (c) the 2019 Incremental Revolving Loan Lender and (d) the Administrative Agent and the Collateral Agent.

2.      The Borrower shall have, to the extent invoiced at least three Business Days prior to the Ninth Amendment Effective Date, reimbursed or paid all reasonable and documented out-of-pocket expenses in connection with this Ninth Amendment and any other reasonable and documented out-of-pocket expenses of the Administrative Agent and the 2019 Incremental Revolving Loan Lender with respect to this Ninth Amendment, including the reasonable and documented out-of-pocket fees, charges and disbursements of counsel for the Administrative Agent and the 2019 Incremental Revolving Loan Lender (and any Affiliate thereof) as required to be paid or reimbursed pursuant to the Credit Agreement.

3.     The Administrative Agent shall have received a customary legal opinion of (i) Stephanie Zapata Moore, Executive Vice President and General Counsel of Vistra Energy Corp., and (ii) Latham & Watkins LLP, New York counsel to the Credit Parties, in each case, addressed to each Revolving Credit Lender party to the Credit Agreement (as modified hereby) (including the 2019 Incremental Revolving Loan Lender), each Revolving Letter of Credit Issuer, the Administrative Agent and the Collateral Agent, dated as of the Ninth Amendment Effective Date and in form and substance reasonably satisfactory to the Administrative Agent.

4.     The Administrative Agent shall have received (w) a certificate from the Chief Financial Officer or Senior Vice President and Treasurer of the Borrower, dated the Ninth Amendment Effective Date, substantially in the form of the certificate provided pursuant to Section  6.9 of the Credit Agreement (with appropriate adjustments to reflect the incurrence of the 2019 Incremental Revolving Credit Commitment (and any related Revolving Credit Loans)) and certifying that, immediately after giving effect to this Ninth Amendment and the 2019 Revolving Commitment Increase and the other transactions contemplated hereby, the Borrower and its Subsidiaries, on a consolidated basis, are Solvent, (x) a certificate of good standing (or subsistence) with respect to each Credit Party from the Secretary of State (or similar official) of the State of such Credit Party’s organization, (y) a closing certificate executed by an Authorized Officer of the Borrower, dated the Ninth Amendment Effective Date, certifying as to the accuracy (with respect to clauses (i), (ii) and (iii) of Section D.2. of this Ninth Amendment, in all material respects) of the matters set forth in Section D.2. of this Ninth Amendment and (z) a certificate executed by an Authorized Officer of the Borrower, dated the Ninth Amendment Effective Date, certifying as to the incumbency and specimen signature of each officer of a Credit Party executing this Ninth Amendment or any other document delivered in connection herewith on behalf of any Credit Party and attaching (A) a true and complete copy of the certificate of incorporation (or other applicable charter document) of each Credit Party, including all amendments thereto, as in effect on the Ninth Amendment Effective Date, certified as of a recent date by the Secretary of State (or analogous official) of the jurisdiction of its organization, that has not been amended since the date of the last amendment thereto shown on the certificate of good standing furnished pursuant to clause (x) above, (B) a true and complete copy of, or certification that there have been no changes to, the by-laws (or other applicable operating agreements) of each Credit Party as in effect on the Ninth Amendment Effective Date and (C) a true and complete copy of resolutions duly adopted or written consents duly executed by the board of directors (or equivalent governing body or any committee thereof) of each Credit Party authorizing the execution, delivery and performance of this Ninth Amendment, the

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performance of the Credit Agreement and the other Credit Documents (in each case, as modified hereby), the incurrence of the 2019 Revolving Commitment Increase and the other transactions contemplated by this Ninth Amendment and certifying that such resolutions or written consents have not been modified, rescinded or amended and are in full force and effect.

5.     No Default or Event of Default shall have occurred and be continuing (both immediately before and immediately after giving effect to this Ninth Amendment and the 2019 Revolving Commitment Increase and the other transactions contemplated by this Ninth Amendment).

6.     The Administrative Agent shall have received a certificate, dated as of the Ninth Amendment Effective Date and executed by an Authorized Officer of the Borrower, certifying that (a) all of the conditions in clauses C.1 through C.5 (inclusive) above have been satisfied on such date, (b) the Borrower is in compliance with the requirements of Section 2.14 of the Credit Agreement and (c) the 2019 Incremental Revolving Credit Commitment were made available, in reliance on clause (3)(x) of the definition of “Maximum Incremental Facilities Amount” set forth in the Credit Agreement.

1.      Credit Agreement Governs . Except as expressly set forth in this Ninth Amendment, the 2019 Incremental Revolving Credit Commitment (and the related Revolving Credit Exposure) shall otherwise be subject to the provisions of the Credit Agreement and the other Credit Documents (in each case, as modified hereby).

2.      Credit Party Certifications . By execution of this Ninth Amendment, each Credit Party hereby certifies, solely with respect to itself and on behalf of the applicable Credit Party and not in his/her individual capacity, that as of the Ninth Amendment Effective Date:

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11.     Waiver of Jury Trial. EACH PARTY HERETO HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES (TO THE EXTENT PERMITTED BY APPLICABLE LAW) TRIAL BY JURY IN ANY LEGAL ACTION OR PROCEEDING RELATING TO THIS NINTH AMENDMENT AND FOR ANY COUNTERCLAIM THEREIN.

12.      Reaffirmation . By executing and delivering a counterpart hereof, (i) each Credit Party hereby agrees that, as of the Ninth Amendment Effective Date and after giving effect to this Ninth Amendment and the transactions contemplated hereby, all Obligations of the Borrower (including, without limitation, the Revolving Credit Exposure with respect to the 2019 Incremental Revolving Credit Commitment) shall be guaranteed pursuant to the Guarantee in accordance with the terms and provisions thereof and shall be secured pursuant to the Security Documents in accordance with the terms and provisions thereof; (ii) each Credit Party hereby (A) agrees that, notwithstanding the effectiveness of this Ninth Amendment, as of the Ninth Amendment Effective Date and after giving effect thereto, the Security Documents continue to be in full force and effect, (B) agrees that, as of the Ninth Amendment Effective Date and after giving effect to this Ninth Amendment and the transactions

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contemplated hereby, all of the Liens and security interests created and arising under each Security Document to which it is a party remain in full force and effect on a continuous basis, and the perfected status and priority of each such Lien and security interest continues in full force and effect on a continuous basis, unimpaired, uninterrupted and undischarged, as collateral security for its Obligations under the Credit Documents (as modified hereby) to which it is a party, in each case, to the extent provided in, and subject to the limitations and qualifications set forth in, such Credit Documents (as modified hereby) and (C) affirms and confirms all of its obligations and liabilities under the Credit Agreement and each other Credit Document (as modified hereby) to which it is a party, in each case after giving effect to this Ninth Amendment and the transactions contemplated hereby, including its guarantee of the Obligations and the pledge of and/or grant of a security interest in its assets as Collateral pursuant to the Security Documents (as modified hereby) to which it is a party to secure such Obligations, all as provided in the Security Documents (as modified hereby), and acknowledges and agrees that, as of the Ninth Amendment Effective Date, such obligations, liabilities, guarantee, pledge and grant continue in full force and effect in respect of, and to secure, such Obligations under the Credit Agreement and the other Credit Documents, in each case after giving effect to this Ninth Amendment and the 2019 Revolving Commitment Increase effected hereby and the other transactions contemplated hereby; and (iii) each Guarantor agrees that nothing in the Credit Agreement, this Ninth Amendment or any other Credit Document shall be deemed to require the consent of such Guarantor to any future amendment to the Credit Agreement.

13.      Miscellaneous. This Ninth Amendment shall constitute a Credit Document for all purposes of the Credit Agreement and the other Credit Documents (in each case, as modified hereby) and shall also constitute an Incremental Amendment. The provisions of this Ninth Amendment are deemed incorporated as of the Ninth Amendment Effective Date into the Credit Agreement as if fully set forth therein. Except as specifically modified by this Ninth Amendment, (i) the Credit Agreement and the other Credit Documents shall remain in full force and effect and (ii) the execution, delivery and performance of this Ninth Amendment shall not constitute a waiver of any provision of, or operate as a waiver of any right, power or remedy of any Agent or Lender under, the Credit Agreement or any of the other Credit Documents.

[SIGNATURES APPEAR ON THE FOLLOWING PAGES]

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IN WITNESS WHEREOF , each of the undersigned has caused its duly authorized officer to execute and deliver this Ninth Amendment as of the date first set forth above.

[ Signature Page to Vistra Operations Company Ninth Amendment ]

[ Signature Page to Vistra Operations Company Ninth Amendment ]

[ Signature Page to Vistra Operations Company Ninth Amendment ]

[ Signature Page to Vistra Operations Company Ninth Amendment ]

[ Signature Page to Vistra Operations Company Ninth Amendment ]

[ Signature Page to Vistra Operations Company Ninth Amendment ]