MASTEC INC

Note 9 –Income Taxes

In determining the quarterly provision for income taxes, management uses an estimated annual effective tax rate based on forecasted annual pre-tax income, permanent tax differences, statutory tax rates and tax planning opportunities in the various jurisdictions in which the Company operates. The effect of significant discrete items is separately recognized in the quarter(s) in which they occur. For the three months ended September 30, 2025 and 2024, the Company’s consolidated effective tax rates were 21.3% and 23.0%, respectively, and for the nine months ended September 30, 2025 and 2024 were 21.2% and 25.8%, respectively. The Company’s effective tax rate for the nine months ended September 30, 2025 included income tax benefits primarily due to the reversal of uncertain tax position liabilities related to a state audit and the release of valuation allowances on certain deferred tax assets that were no longer necessary, offset, in part, by an increase in income tax expense due to higher pre-tax income. For the nine months ended September 30, 2024, the Company’s effective tax rate included the effect of a lower state income tax rate partially offset by a higher percentage of non-deductible expenses relative to pre-tax income.

On July 4, 2025, new tax legislation was signed into law, known as the One Big Beautiful Bill Act (the “OBBBA”), which makes permanent many of the tax provisions enacted in 2017 as part of the Tax Cuts and Jobs Act that were set to expire at the end of 2025. In addition, the OBBBA makes changes to certain U.S. corporate tax provisions, but many are generally not effective until 2026. The Company has undertaken efforts to reasonably estimate the impact of the provisions of the new law and expects that there will be no material impacts to the consolidated financial statements. The Company will continue to evaluate the full impact of these legislative changes as more guidance becomes available.