Vistra Corp.

9. LOSS EVENTS AND INSURANCE RECOVERIES

Moss Landing 300 Incident

On January 16, 2025, we experienced 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. 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, we wrote off the net book value of Moss Landing 300 of approximately $400 million to depreciation expense during the three months ended March 31, 2025. We also determined not to return the Moss Landing 100 MW battery facility to service and recognized an impairment loss of approximately $155 million during the three months ended December 31, 2025. Both facilities were moved to the Asset Closure segment (see Notes 8 and 19 for additional information).

During the three months ended September 30, 2026, we completed our investigation into the cause of the fire. While the investigation provided additional information, management continues to evaluate a potential restart of the Moss Landing 350 MW battery facility and uncertainty remains as to when the facility may return to service. As a result of this continued uncertainty, we performed an impairment analysis using a probability-weighted discounted cash flow approach which resulted in an impairment charge of approximately $269 million during the three months ended September 30, 2026. The facility had a net book value of approximately $37 million as of September 30, 2026.

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, requiring battery removal and remediation activities. Total costs are currently estimated at approximately $175 million, including a $65 million increase recorded during the second quarter of 2026 primarily due to an extended remediation timeline and higher cost estimates. Of the total estimated costs, $105 million had been incurred through September 30, 2026, with the remaining $70 million recorded in other current liabilities in the condensed consolidated balance sheets as of September 30, 2026. Future adjustments will be recognized as a change in estimate in the period new information becomes available.

Additional impacts from the Moss Landing Incident include or may include loss of revenue from the facilities being offline, litigation costs, other negotiated settlements of contracts with counterparties, and additional non-cash impairment losses. See Note 16 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 approximately $500 million, net of deductibles, all of which has been fully collected as of February 2026.

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 September 30, 2026, we have realized property damage insurance proceeds of $255 million and business interruption proceeds of $69 million. During the three and nine months ended September 30, 2026, we realized $54 million and $116 million, respectively, of property damage insurance proceeds. In the three and nine months ended September 30, 2026, we realized zero and $22 million, respectively, of 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.