QUANTA SERVICES, INC.

8. INCOME TAXES:

Quanta’s effective tax rates for the three months ended September 30, 2026 and 2025 were 25.2% and 25.9%. The lower effective tax rate for the three months ended September 30, 2026 was primarily due to changes in the mix of earnings across the jurisdictions in which Quanta operates.

Quanta’s effective tax rates for the nine months ended September 30, 2026 and 2025 were 23.1% and 25.2%. The lower effective tax rate for the nine months ended September 30, 2026 was primarily due to a $33.3 million increase in U.S. federal and state tax benefit from the vesting of equity incentive awards.

As of September 30, 2026, the total amount of unrecognized tax benefits relating to uncertain tax positions was $86.6 million, a net increase of $12.2 million from December 31, 2025, primarily driven by current year positions and additions for prior year positions, partially offset by releases from the expiration of applicable statutes of limitations. Quanta’s consolidated federal income tax return for tax year 2024 is currently under examination by the Internal Revenue Service (IRS), and the consolidated federal income tax return for the 2023 tax year remains open to examination by the IRS, as the applicable statute of limitations periods have not yet expired. Additionally, various state and foreign tax returns filed by Quanta and certain subsidiaries for multiple periods remain under examination by various U.S. state and foreign tax authorities. Quanta does not consider any U.S. state in which it does business to be a major tax jurisdiction.