Vistra Corp.

8. LOSS EVENTS AND INSURANCE RECOVERIES

Moss Landing 300 Incident

On January 16, 2025, we detected a fire at our Moss Landing 300 MW energy storage facility at the Moss Landing Power Plant site (the Moss Landing Incident) that resulted in ceasing operations at all facilities at the Moss Landing complex until the fire was contained. No injuries occurred due to the fire or the Company's response. The Moss Landing complex includestwo other battery facilities and a gas plant. The gas plant returned to service in February 2025.

As a result of the Moss Landing Incident, (i) during the three months ended March 31, 2025, we wrote-off the net book value of Moss Landing 300 of approximately $400 million to depreciation expense and moved the asset to the Asset Closure segment as we have no plans to return the Moss Landing 300 facility to operations (see Notes 7 and 18 for additional information), (ii) we determined not to return the Moss Landing 100 MW battery facility to service, and (iii) we are working towards a return to service of our Moss Landing 350 MW battery facility in mid-2026, pending the evaluation of our restart plans following the completion of our investigation into the cause of the fire, which creates uncertainty as to when or if the facility will return to service. Moss Landing 350 MW battery facility has a net book value of approximately $316 million as of March 31, 2026.

As a result of the decision to not return the Moss Landing 100 MW battery to service, we performed an assessment of the recoverability of the facility's carrying value and, during the three months ended December 31, 2025, we recognized an impairment loss of approximately $155 million and moved the asset to the Asset Closure segment (see Notes 7 and 18 for additional information).

In July 2025, we entered into an Administrative Settlement Agreement and Order on Consent (ASAOC) with the EPA related to the Moss Landing 300 site. Under the ASAOC, we are required to perform specific battery removal and remediation activities, including battery removal and disposal, building demolition, and air and water monitoring. We estimate the total cost of these activities to be approximately $110 million, of which approximately $70 million has been spent through March 31, 2026, including approximately $21 million in the three months ended March 31, 2026. As of March 31, 2026, our accrual for estimated future costs for the ASAOC activities is approximately $40 million, which is reflected in other current liabilities in the condensed consolidated balance sheets. This estimate assumes the ASAOC activities will be completed by the end of 2026. Aside from battery removal and disposal, our estimate does not reflect costs associated with removal of other hazardous waste that could be identified as the demolition progresses as we are unable to estimate such costs until sampling of waste material is complete. We will account for any adjustments to the accrual as a change in estimate in the period new information becomes available.

Additional impacts from the Moss Landing Incident include loss of revenue from the facilities being offline and may include litigation costs, other negotiated settlements of contracts with counterparties, and additional non-cash impairment losses. See Note 15 for additional information. While we expect revenues in the West segment to decrease relative to 2024 due to the Moss Landing 300 MW and 100 MW battery facilities not returning to service, uncertainty regarding the timing of any potential restart of the Moss Landing 350 MW battery facility, as well as the nature and extent of additional costs that may be incurred related to the Moss Landing Incident, limits our ability to predict the full impact on our 2026 financial statements.

We have filed insurance claims against applicable insurance policies with combined business interruption and property loss limits of $500 million, net of deductibles, all of which has been fully collected as of February 2026. During the three months ended March 31, 2026, we received $198 million of property damage insurance proceeds which reduced the property damage insurance receivable and $6 million of business interruption insurance proceeds which is included in operating revenues in the condensed consolidated statements of operations.

Martin Lake Unit 1 Incident

On November 27, 2024, we experienced a fire at Unit 1 of our Martin Lake facility in ERCOT (the Martin Lake Incident), an 815 MW unit. We wrote-off the unit's net book value of less than $1 million to depreciation expense in December 2024. The unit returned to service in February 2026.

We expect to recover a majority of the expenditures associated with the Martin Lake Incident through property damage insurance and to receive additional business interruption proceeds. Through March 31, 2026, we have received property damage insurance proceeds of $153 million and business interruption proceeds of $47 million. During the three months ended March 31, 2026, we received $9 million of property damage insurance proceeds and did not receive any business interruption insurance proceeds. We expect to receive additional property damage and business interruption insurance proceeds related to the incident. These additional proceeds will be recorded as income in the period they are realized.