ASPEN AEROGELS INC Income Taxes Disclosure

(17) Income Taxes

The Company incurred net operating losses for the years ended December 31, 2025 and 2023, and net operating income for the year ended December 31, 2024. The Company incurred net operating losses and recorded a full valuation allowance against net

deferred tax assets for all prior periods. Accordingly, the Company has not recorded a provision for federal income taxes for the years ended December 31, 2025 or 2024.

The Company has recorded a provision for state income taxes of $0.3 million during the year ended December 31, 2025. The Company has incurred $2.1 million and $1.7 million of income tax expense related to its foreign operations, primarily its Mexican maquiladora operations for the years ended December 31, 2025 and 2024, respectively. There was no respective income tax for the year ended December 31, 2023.

The net change in the valuation allowance for the year ended December 31, 2025, was an increase of $82.0 million. The Company has recorded a full valuation allowance against its federal and state net deferred tax assets due to the uncertainty associated with the utilization of the net operating loss carryforwards and other future deductible items. In assessing the realizability of deferred tax assets, the Company considers all available evidence, historical and prospective, with greater weight given to historical evidence, in determining whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of the Company’s deferred tax assets generally is dependent upon generation of future taxable income.

At December 31, 2025, the Company had $372.3 million of net operating losses available to offset future federal income, if any, of which $145.0 million expire on various dates through December 31, 2037. Net operating losses of $227.3 million generated from 2018 through 2025 have an unlimited carryforward.

At December 31, 2025, the Company had $258.0 million of apportioned net operating losses available to offset future state taxable income, if any, and which begin to expire at various dates between 2026 and 2044.

For each of the years ended December 31, 2025, 2024 and 2023, the Company did not have any material unrecognized tax benefits and thus no interest and penalties related to unrecognized tax benefits were recorded.

The Company files a federal income tax return in the United States and income tax returns in various state and foreign jurisdictions. All tax years are open for examination by the taxing authorities for both federal and state purposes.

The Tax Cuts and Jobs Act requires taxpayers to capitalize and amortize research and development (R&D) expenditures under Section 174 of the Internal Revenue Code for tax years beginning after December 31, 2021. R&D costs performed in the United States are amortized over 5 years and over 15 years for R&D performed outside the United States. This rule became effective for the Company during 2022 and resulted in the net capitalization of R&D expenses of $51.4 million as of December 31, 2024. All costs were incurred in the United States.

On July 4, 2025, the One Big Beautiful Bill Act (“OBBBA”) was enacted, which allows for immediate deduction of R&D costs performed in the United States. Expenses related to R&D performed outside the United States will continue to be capitalized and amortized over 15 years. This is applicable for tax years beginning after December 31, 2024. OBBBA also provides certain eligible taxpayers with the option to accelerate the deduction of the remaining unamortized domestic R&D costs incurred during taxable years ending after December 31, 2021 and before January 1, 2025 over one or two years or continue to amortize the remaining unamortized cost over the remaining 5 year lives. The Company intends to continue amortizing the domestic R&D costs over the remaining 5 year lives. Previously unamortized Capitalized R&D costs is $37.4 million as of December 31, 2025.