ASPEN AEROGELS INC 10-K

Item 9A. CONTROLS AND PROCEDURES (a) Evaluation of Disclosure Controls and Procedures . We maintain disclosure controls and procedures that are designed to ensure that information required to be disclosed in the reports that we file or submit under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms and is accumulated and communicated to our management, including our principal executive officer and principal financial officer, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure. As of December 31, 2025, our management, with the participation of our principal executive officer and principal financial officer, evaluated the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act). Our management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives, and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Based on such evaluation, our principal executive officer and principal financial officer have concluded, that, as of December 31, 2025, our disclosure controls and procedures were effective to ensure that information required to be disclosed by us in the reports that we file or submit under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms, and is accumulated and communicated to our management, including our principal executive officer and principal financial officer, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure. (b) Management’s Report on Internal Control over Financial Reporting . The Company’s management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act, as a process designed by, or under the supervision of, the Company’s principal executive and principal financial officers and effected by the Company’s Board of Directors, management and other personnel to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. The Company’s internal control over financial reporting includes those policies and procedures that: • pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the Company; • provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the Company are being made only in accordance with authorizations of management and directors of the Company; and • provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of the Company’s assets that could have a material effect on the financial statements. Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. The Company’s management assessed the effectiveness of the Company’s internal control over financial reporting as of December 31, 2025. In making this assessment, management used the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission in Internal Control-Integrated Framework (2013). Based on our assessment, management believes that, as of December 31, 2025, the Company’s internal control over financial reporting is effective based on those criteria. Our independent registered public accounting firm has issued an attestation report on our assessment of our internal control over financial reporting. This report appears further below in this Item 9A. 122 (c) Changes in Internal Controls . There were no changes in our internal control over financial reporting, as such term is defined in Rules 13a-15(f) and 15(d)-15(f) promulgated under the Exchange Act, identified in connection with the evaluation of such internal control that occurred during the fourth quarter of the last fiscal year that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting. Item 9B. OTHER INFORMATION 10b5-1 Trading Arrangements From time to time, our officers (as defined in Rule 16a-1(f) of the Exchange Act) and directors may enter into Rule 10b5-1 or non-Rule 10b5-1 trading arrangements (as each such term is defined in Item 408 of Regulation S-K). During the three months ended December 31, 2025, none of our officers or directors adopted , modified or terminated any such trading arrangements. Item 9C. DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT INSPECTIONS Not applicable. 123 PART III Item 10. DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE The response to this item will be incorporated by reference from the discussion responsive thereto under the captions “Management and Corporate Governance,” “Delinquent Section 16(a) Reports,” and “Code of Business Conduct and Ethics” in the Company’s Proxy Statement for the 2026 Annual Meeting of Stockholders. Item 11. EXECUTIVE COMPENSATION The response to this item will be incorporated by reference from the discussion responsive thereto under the caption “Executive Compensation,” “Compensation Discussion and Analysis,” “Director Compensation,” “Management and Corporate Governance – Compensation Committee Interlocks and Insider Participation,” “Compensation Committee Report” and “Risks Related to Compensation Practices and Policies” in the Company’s Proxy Statement for the 2026 Annual Meeting of Stockholders. The section titled “Pay Versus Performance” in the Proxy Statement is not incorporated by reference herein. Item 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OW NERS AND MANAGEMENT AND RELATED STOCKHOLDER MATTERS The response to this item will be incorporated by reference from the discussion responsive thereto under the captions “Security Ownership of Certain Beneficial Owners and Management” and “Equity Compensation Plan Information” in the Company’s Proxy Statement for the 2026 Annual Meeting of Stockholders. Item 13. CERTAIN RELATIONSHIPS AND RELATE D TRANSACTIONS, AND DIRECTOR INDEPENDENCE The response to this item will be incorporated by reference from the discussion responsive thereto under the captions “Certain Relationships and Related Person Transactions” and “Management and Corporate Governance” in the Company’s Proxy Statement for the 2026 Annual Meeting of Stockholders. Item 14. PRINCIPAL ACCOU NTING FEES AND SERVICES The response to this item will be incorporated by reference from the discussion responsive thereto under the caption “Independent Registered Public Accounting Firm” in the Company’s Proxy Statement for the 2026 Annual Meeting of Stockholders. 124 PART IV Item 15. EXHIBITS, FINANCIAL STATEMENT SCHEDULES Item 15(a). The following documents are filed as part of this Annual Report on Form 10-K: Item 15(a)(1). The following consolidated financial statements of the Company are included in Part II, Item 8 of this Annual Report on Form 10-K: Report of Independent Registered Public Accounting Firm Consolidated Balance Sheets as of December 31, 2025 and 2024 Consolidated Statements of Operations for the Years Ended December 31, 2025, 2024, and 2023 Consolidated Statements of Stockholders’ Equity for the Years Ended December 31, 2025, 2024 and 2023 Consolidated Statements of Cash Flows for the Years Ended December 31, 2025, 2024 and 2023 Notes to Consolidated Financial Statements Item 15(a)(2). The following financial statements schedule is included in Part II, Item 8: Schedule II – Valuation and Qualifying Accounts All other financial statement schedules have not been included because they are not applicable or the information is included in the financial statements or notes thereto. Item 15(a)(3). Exhibits: The following is a list of exhibits filed as part of this Annual Report on Form 10-K. Exhibit Number Exhibit Description Filed with this Report Incorporated by Reference herein from Form or Schedule Filing Date SEC File/Reg. Number 3.1 Restated Certificate of Incorporation of the Registrant, as filed with the Secretary of State of the State of Delaware on June 18, 2014. Form 8-K (Exhibit 3.2) 6/19/14 001-36481 3.1.1 Certificate of Amendment to Restated Certificate of Incorporation of Aspen Aerogels, Inc., dated June 1, 2023. Form 8-K (Exhibit 3.1) 6/1/23 001-36481 3.2 Amended and Restated Bylaws of Aspen Aerogels, Inc. Form 10-K (Exhibit 3.2) 3/7/24 001-36481 4.1 Form of Common Stock Certificate. Amendment No. 1 to Form S-1 (Exhibit 4.1) 5/14/14 333-195523 4.2 Description of Securities. Form 10-K (Exhibit 4.3) 3/6/20 001-36481 10.1+ 2014 Employee, Director and Consultant Equity Incentive Plan. Form S-8 (Exhibit 99.10) 8/13/14 333-198124 10.1.1+ Form of Stock Option Agreement Granted under 2014 Employee, Director and Consultant Equity Incentive Plan. Amendment No. 1 to Form S-1 (Exhibit 10.2.2) 5/14/14 333-195523 10.1.2+ Form of Restricted Stock Unit Agreement for Executive Officers under 2014 Employee, Director and Consultant Equity Incentive Plan. Form 10-Q (Exhibit 10.3) 11/7/14 001-36481 125 Exhibit Number Exhibit Description Filed with this Report Incorporated by Reference herein from Form or Schedule Filing Date SEC File/Reg. Number 10.1.3+ Form of Restricted Stock Agreement for Directors under 2014 Employee, Director and Consultant Equity Incentive Plan. Amendment No. 1 to Form S-1 (Exhibit 10.2.3) 5/14/14 333-195523 10.1.4+ Form of Performance-Based Restricted Stock Agreement for Certain Employees under 2014 Employee, Director and Consultant Equity Incentive Plan. Form 10-Q (Exhibit 10.2) 8/4/22 001-36481 10.2+ Aspen Aerogels 2023 Equity Incentive Plan. Form 8-K (Exhibit 10.1) 5/1/25 001-36481 10.2.1+ Form of Stock Option Agreement under the Aspen Aerogels 2023 Equity Incentive Plan. Form 8-K (Exhibit 10.2) 6/1/23 001-36481 10.2.2+ Form of Restricted Stock Unit Agreement for Executive Officers under the Aspen Aerogels 2023 Equity Incentive Plan. Form 8-K (Exhibit 10.3) 6/1/23 001-36481 10.2.3+ Form of Restricted Stock Agreement for Directors under the Aspen Aerogels 2023 Equity Incentive Plan. Form 8-K (Exhibit 10.4) 6/1/23 001-36481 10.2.4+ Form of Director Stock Option Agreement under the Aspen Aerogels 2023 Equity Incentive Plan. Form 8-K (Exhibit 10.5) 6/1/23 001-36481 10.2.5+ Form of Performance Share Unit Agreement under the Aspen Aerogels 2023 Equity Incentive Plan. Form 8-K (Exhibit 10.1) 3/7/25 001-36481 10.2.6+ Aspen Aerogels Employee Stock Purchase Plan. Form 8-K (Exhibit 10.2) 5/1/25 001-36481 10.3 Multi-Tenant Industrial Net Lease, dated August 20, 2001, by and between the Registrant and Cabot II — MA1M03, LLC (as successor landlord to TMT290 Industrial Park, Inc.), as amended. Form S-1 (Exhibit 10.3) 4/28/14 333-195523 10.3.1 First Amendment to Lease, dated December 22, 2021, by and between the Registrant and G&I IX Forbes Whitney, LLC. Form 10-K (Exhibit 10.14.1) 3/1/22 001-36481 10.4 Loan Agreement, dated November 28, 2022, by and between the Registrant, Aspen Aerogels Georgia LLC, Aspen Aerogels Rhode Island, LLC and General Motors Holdings LLC. Form 8-K (Exhibit 10.1) 11/29/22 001-36481 10.4.1 First Amendment, dated September 28, 2023, to the Loan Agreement, dated November 28, 2022, by and among the Company, Aspen Aerogels Georgia, LLC, Aspen Aerogels Rhode Island, LLC and General Motors Holdings LLC. Form 10-Q (Exhibit 10.2) 11/2/23 001-36481 10.5+ Amended and Restated Executive Employment Agreement, dated November 4, 2025, by and between the Company and Gregg Landes. X 10.5.1+ Executive Employment Agreement, dated January 1, 2023, by and between the Company and Keith Schilling. Form 10-K (Exhibit 10.18(7)) 3/16/23 001-36481 10.5.2+ Amended and Restated Executive Employment Agreement, dated November 4, 2025, by and between the Company and Corby Whitaker. X 10.5.3+ Executive Employment Agreement, dated September 14, 2023, by and between the Company and Santhosh Daniel. Form 10-Q (Exhibit 10.1) 11/2/23 001-36481 126 Exhibit Number Exhibit Description Filed with this Report Incorporated by Reference herein from Form or Schedule Filing Date SEC File/Reg. Number 10.5.4+ Executive Employment Agreement, effective as of October 1, 2025, by and between the Company and Grant Thoele. Form 8-K (Exhibit 10.1) 9/11/25 001-36481 10.5.5+ Executive Employment Agreement, effective as of September 22, 2025, by and between the Company and Glenn Deegan. Form 10-Q (Exhibit 10.2) 11/6/25 001-36481 10.5.6+ Amended and Restated Executive Employment Agreement, dated as of August 30, 2024, by and between the Company and Donald R. Young. Form 8-K (Exhibit 10.1) 9/3/24 001-36481 10.5.7+ Confidential Separation and Release Agreement, dated October 1, 2025, by and between the Company and Stephanie Pittman. Form 10-Q (Exhibit 10.3) 11/6/25 001-36481 10.6+ Aspen Aerogels, Inc. Bonus Plan (Amended and Restated Effective as of January 1, 2024). Form 10-Q (Exhibit 10.3) 11/2/23 001-36481 10.7+ Form of Participation Letter of Executive Officers under Aspen Aerogels, Inc. Bonus Plan. Form 10-K (Exhibit 10.23) 3/2/17 001-36481 10.8+ Non-Employee Director Compensation Policy. Form 10-Q (Exhibit 10.1) 8/8/24 001-36481 10.9* Cross License Agreement, dated as of April 1, 2006, by and between Cabot Corporation and the Company, as amended. Form S-1 (Exhibit 10.17) 4/28/14 333-195523 10.10+ Form of Indemnification Agreement with Directors and Certain Officers. Amendment No. 1 to Form S-1 (Exhibit 10.18) 5/14/14 333-195523 10.11 Inducement Agreement, dated as of February 17, 2022, by and among Aspen Aerogels Georgia, LLC, the Development Authority of Bulloch County, the City of Statesboro, and Bulloch County, Georgia. Form 10-Q (Exhibit 10.1) 5/10/22 001-36481 10.12 PILOT Agreement, dated as of February 17, 2022, by and among Aspen Aerogels Georgia, LLC and the Development Authority of Bulloch County. Form 10-Q (Exhibit 10.3) 5/10/22 001-36481 10.13 Performance and Accountability Agreement, dated as of February 17, 2022, by and among Aspen Aerogels Georgia, LLC, the Development Authority of Bulloch County, and the Georgia Department of Community Affairs. Form 10-Q (Exhibit 10.4) 5/10/22 001-36481 10.14 Memorandum of Understanding, dated as of February 17, 2022, by and between Aspen Aerogels Georgia, LLC, the Development Authority of Bulloch County and the Georgia Department of Economic Development. Form 10-Q (Exhibit 10.2) 5/10/22 001-36481 10.15+ SEIG Award Cancellation Agreement, dated March 6, 2024 (Donald R. Young) Form 8-K (Exhibit 10.1+) 3/7/24 001-36481 10.16 Form of SEIG Award Cancellation Agreement, dated March 6, 2024 (Other Employees) Form 8-K (Exhibit 10.2+) 3/7/24 001-36481 10.17** Supply Agreement, dated February 3, 2021, by and between the registrant and Silbond Corporation. Form 10-Q (Exhibit 10.1) 5/4/21 001-36481 127 Exhibit Number Exhibit Description Filed with this Report Incorporated by Reference herein from Form or Schedule Filing Date SEC File/Reg. Number 10.18+ Performance-Based Restricted Stock Agreement, dated as of June 29, 2021, by and between the Registrant and Donald R. Young. Form 10-Q (Exhibit 10.3) 8/4/21 001-36481 10.19† Credit, Security and Guaranty Agreement, dated as of August 19, 2024, by and among Aspen Aerogels, Inc., Aspen Aerogels Rhode Island, LLC, MidCap Fund IV Trust and MidCap Financial Trust. Form 8-K (Exhibit 10.2) 8/19/24 001-36481 10.19.1† Amendment No. 1 and Joinder, dated May 6, 2025, to the Credit, Security and Guaranty Agreement, dated August 19, 2024, by and among Aspen Aerogels, Inc., Aspen Aerogels Rhode Island, LLC, Aspen Aerogels Georgia, LLC, Aspen Aerogels Mexico Holdings, LLC, MidCap Fund IV Trust and MidCap Financial Trust. Form 10-Q (Exhibit 10.2) 5/8/25 001-36481 10.19.2† Amendment No. 2, dated December 16, 2025, to the Credit, Security and Guaranty Agreement, dated August 19, 2024, by and among Aspen Aerogels, Inc., Aspen Aerogels Rhode Island, LLC, Aspen Aerogels Mexico Holdings, LLC, Aspen Aerogels Georgia, LLC, MidCap Funding IV Trust and MidCap Financial Trust. Form 8-K (Exhibit 10.1) 12/18/25 001-36481 14.1 Code of Business Conduct and Ethics. Form 10-K (Exhibit 14.1) 2/27/25 001-36481 19.1 Insider Trading Policy of Aspen Aerogels, Inc. Form 10-K (Exhibit 19.1) 2/27/25 001-36481 21.1 Subsidiaries of the Registrant. X 23.1 Consent of KPMG LLP. X 31.1 Certification of principal executive officer under Section 302(a) of the Sarbanes-Oxley Act of 2002. X 31.2 Certification of principal financial officer under Section 302(a) of the Sarbanes-Oxley Act of 2002. X 32# Certifications of the principal executive officer and the principal financial officer under Section 906 of the Sarbanes-Oxley Act of 2002. X 97 Compensation Recoupment Policy (Amended and Restated Effective June 1, 2023). Form 10-K (Exhibit 97) 3/7/24 001-36481 101.INS XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document. X 101.SCH Inline XBRL Taxonomy Extension Schema Document. X 104 Cover Page Interactive Data File (embedded within the Inline XBRL document). X 128 + Management contract or compensatory plan or arrangement. * Confidential treatment has been granted with respect to certain portions of this Exhibit, which portions have been omitted and filed separately with the Securities and Exchange Commission as part of an application for confidential treatment pursuant to the Securities Act of 1933, as amended. ** Certain confidential portions of this Exhibit were omitted by means of marking such portions with brackets (“[***]”) because the identified confidential portions (i) are not material and (ii) would be competitively harmful if publicly disclosed. † Certain exhibits and schedules have been omitted in accordance with Item 601(a)(5) of Regulation S-K. The registrant agrees to furnish supplementally a copy of any omitted exhibit or schedule to the Securities and Exchange Commission upon its request. # The certification attached as Exhibit 32 that accompanies this Annual Report on Form 10-K is not deemed filed with the SEC and is not to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, whether made before or after the date of this Annual Report on Form 10-K, irrespective of any general incorporation language contained in such filing. Item 16. FORM 10-K SUMMARY None. 129 SIGNAT URES Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. ASPEN AEROGELS, INC. Date: March 13, 2026 By: /s/ Donald R. Young Donald R. Young President and Chief Executive Officer (principal executive officer) Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities indicated below and on the dates indicated. Signature Title Date /s/ Donald R. Young Donald R. Young President, Chief Executive Officer and Director (principal executive officer) March 13, 2026 /s/ Grant Thoele Grant Thoele Chief Financial Officer and Treasurer (principal financial officer) March 13, 2026 /s/ Santhosh P. Daniel Chief Accounting Officer (principal accounting officer) March 13, 2026 Santhosh P. Daniel /s/ William P. Noglows William P. Noglows Chairperson of the Board March 13, 2026 /s/ James E. Sweetnam James E. Sweetnam Director March 13, 2026 /s/ Kathleen M. Kool Kathleen M. Kool Director March 13, 2026 /s/ Steven R. Mitchell Steven R. Mitchell Director March 13, 2026 /s/ Cari Robinson Cari Robinson Director March 13, 2026 130