Vistra Corp.

21. SEGMENT INFORMATION

The operations of Vistra are aligned into five reportable business segments: (i) Retail, (ii) Texas, (iii) East, (iv) West, and (v) Asset Closure. Our Chief Executive Officer is our chief operating decision maker (CODM). Our CODM reviews the results of these segments separately and allocates resources to the respective segments as part of our strategic operations. A measure of assets is not applicable, as segment assets are not regularly reviewed by the CODM for evaluating performance or allocating resources. In the fourth quarter of 2024, we updated our reportable segments to reflect changes in how the Company's CODM makes operating decisions, assesses performance, and allocates resources by removing the Sunset segment. The results of the plants previously included in the Sunset segment are now reflected in the Texas and East segments based on their respective geographies.

The Retail segment is engaged in retail sales of electricity and natural gas to residential, commercial, and industrial customers. Substantially all of these activities are conducted by TXU Energy, Ambit Energy, Dynegy Energy Services, Homefield Energy, Energy Harbor, and U.S. Gas & Electric across 16 states and the District of Columbia.

The Texas and East segments are engaged in electricity generation, wholesale energy sales and purchases, commodity risk management activities, fuel procurement, and logistics management. The Texas segment represents results from all of Vistra's electricity generation operations in the ERCOT market except for assets included in the Asset Closure segment. The East segment represents results from Vistra's electricity generation operations in the Eastern Interconnection of the U.S. electric grid, other than assets included in the Asset Closure segment, and includes operations in the PJM, MISO, ISO-NE, and NYISO markets.

The West segment represents results from the CAISO market, including our battery ESS project at our Moss Landing power plant site. The Moss Landing 300 MW and Moss Landing 100 MW battery facilities were transferred to the Asset Closure segment in the first quarter of 2025 and fourth quarter of 2025, respectively, as a result of the Moss Landing Incident (see Note 8 for additional information). Management concluded that the 2023 and 2024 revenues, expenses, and capital expenditures associated with the Moss Landing 100 MW battery were immaterial, therefore, prior‑period segment results have not been recast.

The Asset Closure segment is engaged in the decommissioning and reclamation of retired generation facilities, including mines, and battery removal and remediation activities. When facilities are transferred to the Asset Closure segment, prior period results are retrospectively adjusted for comparative purposes, provided the effects are material (see Note 7 for additional information). By separately reporting the Asset Closure segment, management gains improved insights into the performance and earnings potential of Vistra's ongoing operations while actively monitoring the cost associated with Asset Closure activities.

Corporate and Other represents the remaining non-segment operations consisting primarily of general corporate expenses, interest, taxes, other expenses, and nuclear fuel cash capital expenditures not allocated to our operating segments.

The accounting policies of the business segments are the same as those described in the summary of significant accounting policies in Note 1. Our CODM uses more than one measure to assess segment performance, but primarily focuses on Adjusted EBITDA. While we believe this is a useful metric in evaluating operating performance, it is not a metric defined by U.S. GAAP and may not be comparable to non-GAAP metrics presented by other companies. Adjusted EBITDA is most comparable to consolidated Net income (loss) prepared based on U.S. GAAP. The CODM uses net income in competitive analysis by benchmarking to the Company's competitors and evaluating drivers of segment profits available to the Company's equity holders. We account for intersegment sales and transfers as if the sales or transfers were to third parties, that is, at market prices. Certain shared services costs are allocated to the segments. Substantially all income tax (expense) benefit is recognized in Corporate and Other.

(b)Includes nuclear fuel amortization of $133 million and $354 million, respectively, in the Texas and East segments.

(c)Other includes impairment of long-lived assets and other income, net.

(b)Includes nuclear fuel amortization of $105 million and $282 million, respectively, in the Texas and East segments.

(c)Other includes other income, net and the impacts of the Tax Receivable Agreement.

(b)Other includes impairment of long-lived assets, other income, net and the impacts of the Tax Receivable Agreement.