Vistra Corp.

5. INCOME TAXES

Vistra files a U.S. federal income tax return that includes the results of its consolidated subsidiaries. Vistra serves as the corporate parent of the Vistra consolidated group. Pursuant to applicable U.S. Department of the Treasury regulations and published guidance of the IRS, corporations that are members of a consolidated group have joint and several liability for the taxes of such group.

Income Tax Expense

The components of our income tax (expense) benefit are as follows:

We evaluate and update our annual effective income tax rate on an interim basis based on current and forecasted earnings and tax laws. The mix and timing of our actual earnings compared to annual projections, as well as the amount of pre-tax earnings in comparison to the required discrete items, can cause interim effective tax rate fluctuations.

For the three months ended June 30, 2025, the effective rate of 18.9% was lower than the U.S. federal statutory rate of 21% due primarily to permanent differences recorded discretely related to stock-based compensation. For the six months ended June 30, 2025, the effective tax rate of 243.9% was higher than the U.S. federal statutory rate of 21% due primarily to permanent differences recorded discretely related to stock-based compensation, partially offset by state income taxes and the discrete impact of mark-to-market adjustments accounted for outside of the Company's forecasted annual effective income tax rate.

For the three months ended June 30, 2024, the effective tax rate of 25.4% was higher than the U.S. federal statutory rate of 21% due primarily to state income taxes. For the six months ended June 30, 2024, the effective tax rate of 22.3% was higher than the U.S. federal statutory rate of 21% due primarily to permanent differences recorded discretely related to stock-based compensation and state income taxes.

OBBBA and CAMT

In July 2025, the U.S. enacted the budget and reconciliation package known as the One Big Beautiful Bill Act (OBBBA). We are analyzing the law and reviewing the impacts. Any impacts to our tax accounts will be recorded in the three months ended September 30, 2025. We do not expect Vistra to be subject to the corporate alternative minimum tax (CAMT) in the 2025 tax year as it applies only to corporations with a three-year average annual adjusted financial statement income in excess of $1 billion. We have taken the CAMT and forecasted OBBBA impacts into account when forecasting cash taxes.