ASPEN AEROGELS INC

(a)Amendment to MidCap Loan Facility

On May 6, 2025, the Company, Aspen RI, Aspen Mexico and Aspen Aerogels Georgia, LLC, a Georgia limited liability company (“Aspen Georgia”) entered into that certain Amendment No. 1 and Joinder to Credit, Security and Guaranty Agreement (“Amendment No. 1”), by and among us, Aspen RI, Aspen Mexico, Aspen Georgia, MidCap Funding IV Trust, as Agent, MidCap Financial Trust, as term loan servicer, and the Lenders party thereto, amending the MidCap Loan Facility (the MidCap Loan Facility, as amended by Amendment No. 1, the “Amended MidCap Loan Facility”).

As a result of Amendment No. 1, the applicable margin under the MidCap Loan Facility has been amended such that upon the effectiveness of Amendment No. 1, (a) (i) Loans borrowed under the Term Loan Facility will bear interest rate equal to Term SOFR (as defined in the Amended MidCap Loan Facility) for one-month interest period plus 5.00% per year, subject to a Term SOFR floor of 4.50% and a Term SOFR cap of 7.50% and (ii) Loans borrowed under the Revolving Facility will bear interest rate equal to Term SOFR for one-month interest period plus 5.10% per year, subject to a Term SOFR floor of 2.50%, in each case of (i) and (ii), until the first Pricing Date (as defined in Amended MidCap Loan Facility as the date five business days after the delivery of a compliance certificate to the Agent for the most recently ended fiscal quarter) after December 31, 2025 and (b) on such first Pricing Date and as thereafter adjusted on each Pricing Date (i) Loans borrowed under the Term Loan Facility will bear interest equal to Term SOFR for one-month interest period plus a margin equal to (x) if the recently reported EBITDA (as defined in the Amended MidCap Loan Facility) is equal to or above $50 million, 4.50% or (y) if the recently reported EBITDA is below $50 million, 5.00%, in each case of (x) and (y), subject to a Term SOFR floor of 4.50% and a Term SOFR cap of 7.50%, and (ii) Loans borrowed under the Revolving Facility will bear interest equal to Term SOFR for one-month interest period plus a margin equal to (x) if the recently reported EBITDA is equal to or above $50 million, 4.60% or (y) if the recently reported EBITDA is below $50 million, 5.10%, in each case of (x) and (y), subject to a Term SOFR floor of 2.50%. The schedule for amortization of principal of the Term Loan Facility (which remains payable on the last day of each fiscal quarter with remaining principal amount payable on the maturity date) has also been updated with new amounts as set forth in the Amended MidCap Loan Facility.

Pursuant to Amendment No. 1, the financial covenants under the MidCap Loan Facility have been amended such that (a) the minimum Liquidity (as defined in the Amended MidCap Loan Facility) which must be maintained at all times has changed from $75 million to an amount equal to the greater of (i) $50 million and (ii) 85% of the then aggregate outstanding principal amount of the Term Loan Facility and (b) the minimum EBITDA level to be tested quarterly has changed to reflect a new range from $15 million to $50 million, with the next test set at $15 million with respect to the fiscal quarter ended June 30, 2025 and a $50 million level applicable commencing with the fiscal quarter ended December 31, 2027 and thereafter. The Liquidity amount trigger of a cash dominion event has also been reduced from $100 million to an amount equal to the greater of (i) $50 million and (ii) 85% of the then aggregate outstanding principal amount of the Term Loan Facility.

Under Amendment No. 1, Aspen Georgia has become a borrower under the Amended MidCap Loan Facility and has (a) guaranteed the obligations of the Credit Parties (as defined in the Amended MidCap Loan Facility) and (b) granted Agent for the benefits of the Lenders a lien on substantially all of its existing and after-acquired assets, in each case, subject to customary exceptions.

The foregoing description of Amendment No. 1 does not purport to be complete and is qualified in its entirety by reference to the full text of Amendment No. 1, a copy of which is filed as an exhibit to this Quarterly Report on Form 10-Q and incorporated by reference herein.

Departure of Executive Officer

On May 6, 2025, we and Virginia H. Johnson, our Chief Legal Officer, General Counsel and Corporate Secretary, determined that Ms. Johnson will depart the Company, effective as of May 23, 2025, to pursue other opportunities outside of the Company. Ms. Johnson’s departure is not related to any disagreement with the Company on any matter relating to the Company’s operations, policies or practices.

(c)10b5-1 Trading Plans

None of our directors or executive officers adopted, modified orterminated 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 such term is defined in Item 408(a) of Regulation S-K, during the fiscal quarter ended March 31, 2025.