What changed in this filing

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Item 9A. Controls and Procedures

2026-03-13 compared with 2025-02-27 · 54 added, 66 removed, 162 unchanged (43% of the section changed)

1 unchanged sentence

(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 Securities Exchange Act of 1934, as amended, or 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.

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).

11 unchanged sentences

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, or COSO, in Internal Control-Integrated Framework (2013).

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.

4 unchanged sentences

OTHER INFORMATION

Rule 10b5-1 Trading Plans

During the fiscal quarter ended December 31, 2024 , the following of our directors or executive officers adopted , modified or terminated any contract, instruction or written plan for the purchase or sale of our securities that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) or any “non-Rule 10b5-1 trading arrangement” as defined in Item 408(c) of Regulation S-K:

On November 12, 2024 , Corby Whitaker , our Senior Vice President, Sales and Marketing , adopted a Rule 10b5-1 Sales Plan.

The plan is intended to satisfy the affirmative defense of Rule 10b5-1(c) and provides for the sale of up to an aggregate of 198,272 shares of our common stock, plus the net number of shares of our common stock underlying certain restricted stock unit (“RSU”) awards, until November 30, 2025 .

The number of shares to be sold pursuant to the Rule 10b5-1 trading arrangement is indeterminable with respect to the RSU awards, as such number is subject to the number of shares that will be automatically sold to satisfy applicable tax withholding obligations upon vesting of the RSU awards, which will vary based on the market price of our common stock at the time of vesting.

On November 13, 2024 , Keith Schilling , our Senior Vice President, Technology , adopted a Rule 10b5-1 Sales Plan.

The plan is intended to satisfy the affirmative defense of Rule 10b5-1(c) and provides for the sale of up to an aggregate of 37,786 shares of our common stock, plus the net number of shares of our common stock underlying certain restricted stock unit (“RSU”) awards, until September 30, 2025 .

On November 15, 2024 , Stephanie Pittman , our Chief Human Resources Officer , adopted a Rule 10b5-1 Sales Plan.

The plan is intended to satisfy the affirmative defense of Rule 10b5-1(c) and provides for the sale of up to an aggregate of 48,502 shares of our common stock until November 11, 2025 .

On November 15, 2024 , Gregg Landes , our Senior Vice President, Operations and Strategic Development , adopted a Rule 10b5-1 Sales Plan.

The plan is intended to satisfy the affirmative defense of Rule 10b5-1(c) and provides for the sale of up to an aggregate of 261,836 shares of our common stock, plus the net number of shares of our common stock underlying certain restricted stock unit (“RSU”) awards, until November 30, 2025 .

On November 26, 2024 , Virginia H.

Johnson , our Chief Legal Officer, General Counsel & Corporate Secretary , adopted a Rule 10b5-1 Sales Plan.

The plan is intended to satisfy the affirmative defense of Rule 10b5-1(c) and provides for the sale of up to an aggregate of 92,330 shares of our common stock, plus the net number of shares of our common stock underlying certain restricted stock unit (“RSU”) awards, until November 30, 2025 .

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.

DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT INSPECTIONS

1 unchanged sentence

DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

The response to this item is 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 2025 Annual Meeting of Stockholders.

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.

EXECUTIVE COMPENSATION

The response to this item is 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 2025 Annual Meeting of Stockholders.

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.

SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OW NERS AND MANAGEMENT AND RELATED STOCKHOLDER MATTERS

The response to this item is 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 2025 Annual Meeting of Stockholders.

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.

CERTAIN RELATIONSHIPS AND RELATE D TRANSACTIONS, AND DIRECTOR INDEPENDENCE

The response to this item is 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 2025 Annual Meeting of Stockholders.

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.

PRINCIPAL ACCOU NTING FEES AND SERVICES

The response to this item is incorporated by reference from the discussion responsive thereto under the caption “Independent Registered Public Accounting Firm” in the Company’s Proxy Statement for the 2025 Annual Meeting of Stockholders.

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.

EXHIBITS, FINANCIAL STATEMENT SCHEDULES

44 unchanged sentences

(Exhibit 10.2.3)

Form of Performance-Based Restricted Stock Agreement for Certain Employees under 2014 Employee, Director and Consultant Equity Incentive Plan.

(Exhibit 10.2)

Aspen Aerogels 2023 Equity Incentive Plan.

8 unchanged sentences

(Exhibit 10.5)

Form of Performance Share Unit Agreement under the Aspen Aerogels 2023 Equity Incentive Plan.

(Exhibit 10.1)

Aspen Aerogels Employee Stock Purchase Plan.

(Exhibit 10.2)

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.

2 unchanged sentences

(Exhibit 10.14.1)

Form of Performance-Based Restricted Stock Agreement for certain employees +

(Exhibit 10.2)

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.

2 unchanged sentences

(Exhibit 10.2)

Executive Employment Agreement, dated January 1, 2023, by and between the Registrant and Ricardo C.

(Exhibit 10.18(3))

Executive Employment Agreement, dated January 1, 2023, by and between the Registrant and Gregg Landes.+

(Exhibit 10.18(5))

Executive Employment Agreement, dated March 25, 2022, by and between the Registrant and Virginia H.

(Exhibit 10.18(6))

Executive Employment Agreement, dated January 1, 2023, by and between the Registrant and Keith Schilling.+

(Exhibit 10.18(7))

Executive Employment Agreement, dated January 1, 2023, by and between the Registrant and Corby Whitaker.+

Amended and Restated Executive Employment Agreement, dated November 4, 2025, by and between the Company and Gregg Landes.

Executive Employment Agreement, dated January 1, 2023, by and between the Company and Keith Schilling.

(Exhibit 10.18(7))

Executive Employment Agreement, dated September 14, 2023, by and between the Registrant and Santhosh Daniel.+

Amended and Restated Executive Employment Agreement, dated November 4, 2025, by and between the Company and Corby Whitaker.

Executive Employment Agreement, dated September 14, 2023, by and between the Company and Santhosh Daniel.

(Exhibit 10.1)

2 unchanged sentences

SEC File/Reg.

Executive Employment Agreement, dated September 5, 2023, by and between the Registrant and Stephanie Pittman.+

Executive Employment Agreement, effective as of October 1, 2025, by and between the Company and Grant Thoele.

(Exhibit 10.1)

Executive Employment Agreement, effective as of September 22, 2025, by and between the Company and Glenn Deegan.

(Exhibit 10.2)

Amended and Restated Executive Employment Agreement, dated as of August 30, 2024, by and between the Company and Donald R.

(Exhibit 10.1)

Confidential Separation and Release Agreement, dated October 1, 2025, by and between the Company and Stephanie Pittman.

(Exhibit 10.3)

Aspen Aerogels, Inc.

1 unchanged sentence

(Exhibit 10.3)

Form of participation letter of executive officers under bonus plan.

Form of Participation Letter of Executive Officers under Aspen Aerogels, Inc.

(Exhibit 10.23)

1 unchanged sentence

(Exhibit 10.1)

Cross License Agreement, dated as of April 1, 2006, by and between Cabot Corporation and the Registrant, as amended.*

Cross License Agreement, dated as of April 1, 2006, by and between Cabot Corporation and the Company, as amended.

(Exhibit 10.17)

9 unchanged sentences

(Exhibit 10.4)

Securities Purchase Agreement, dated February 15, 2022, by and between the Registrant and Wood River Capital, LLC.

(Exhibit 10.2)

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.

6 unchanged sentences

(Exhibit 10.1)

Exhibit Description

Incorporated by

SEC File/Reg.

Performance-Based Restricted Stock Agreement, dated as of June 29, 2021, by and between the Registrant and Donald R.

(Exhibit 10.3)

Note Purchase and Sale Agreement, dated as of August 19, 2024, by and between Aspen Aerogels, Inc.

and Wood River Capital, LLC.*

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.

(Exhibit 10.2)

Credit, Security and Guaranty Agreement, dated as of August 19, 2024, by and among Aspen Aerogels, Inc., Aspen

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.

(Exhibit 10.2)

Exhibit Description

Incorporated by

SEC File/Reg.

Aerogels Rhode Island, LLC, MidCap Fund IV Trust and MidCap Financial Trust.*

Amended and Restated Executive Employment Agreement, dated as of August 30, 2024, by and between the Company and Donald R.

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.

(Exhibit 10.1)

Code of Business Conduct and Ethics.

(Exhibit 14.1)

Insider Trading Policy of Aspen Aerogels, Inc.

(Exhibit 19.1)

Subsidiaries of the Registrant.

6 unchanged sentences

Inline XBRL Taxonomy Extension Schema Document.

Inline XBRL Taxonomy Extension Calculation Linkbase Document.

Inline XBRL Taxonomy Extension Definition Linkbase Document.

Inline XBRL Taxonomy Extension Label Linkbase Document.

Inline XBRL Taxonomy Extension Presentation Linkbase Document.

Cover Page Interactive Data File (embedded within the Inline XBRL document).

1 unchanged sentence

* 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.

FORM 10-K SUMMARY

1 unchanged sentence

ASPEN AEROGELS, INC.

February 27, 2025

March 13, 2026

/s/ Donald R.

5 unchanged sentences

and Director (principal executive

February 27, 2025

/s/ Ricardo C.

March 13, 2026

/s/ Grant Thoele

Chief Financial

1 unchanged sentence

financial officer)

February 27, 2025

March 13, 2026

/s/ Santhosh P.

Chief Accounting Officer (principal accounting officer)

February 27, 2025

March 13, 2026

/s/ William P.

Chairperson of the Board

February 27, 2025

/s/ Rebecca B.

February 27, 2025

March 13, 2026

/s/ Kathleen M.

February 27, 2025

March 13, 2026

/s/ Steven R.

February 27, 2025

March 13, 2026

/s/ Cari Robinson

Cari Robinson

February 27, 2025

March 13, 2026

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 9A. Controls and Procedures