Gevo, Inc.

Management’s Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our chief executive officer (principal executive officer) and chief financial officer (principal financial officer), conducted an evaluation of the effectiveness of our disclosure controls and procedures for the reporting period ended September 30, 2026, as such terms is defined in Rule 13a-15(f) under the Exchange Act. Based on that evaluation, our chief executive officer and chief financial officer concluded that, as of the end of the period covered by this report, the Company’s disclosure controls and procedures were not effective due to a material weakness in the Company’s internal control over financial reporting, as previously disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025. Notwithstanding this material weakness, management has concluded that the condensed consolidated financial statements included in this Quarterly Report are fairly stated in all material respects in accordance with U.S. GAAP.

Ongoing Remediation of Previously Identified Material Weakness

Management has identified a material weakness in the Company’s internal control over financial reporting related to information technology general controls within certain financial systems of a recently acquired entity. During the nine months ended September 30, 2026, management initiated remediation efforts, including enhancing user access controls, strengthening change management procedures, and integrating the acquired entity’s ERP system with the Company’s existing systems and applications.

Changes in Internal Control over Financial Reporting

There have been no other changes in our internal control over financial reporting that occurred during the three months ended September 30, 2026 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.