Gevo, Inc.

Evaluation of Disclosure Controls and Procedures

We maintain disclosure controls and procedures, as such term is defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, that are designed to provide reasonable assurance 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 rules and forms, and that such information is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate, to allow timely decisions regarding required financial disclosures.

As previously reported in our Annual Report on Form 10-K for the year ended December 31, 2024, we have determined that we did not maintain a sufficient complement of personnel with the necessary technical expertise and accounting knowledge to appropriately address complex and non-routine transactions, which control deficiency constitutes a material weakness.

In addition, as part of our post-acquisition internal control design and effectiveness testing (typically conducted in the first year following an acquisition), we discovered a material weakness resulting from the failure to design and maintain effective segregation of duties related to the preparation and review of journal entries at the Company’s GevoND operations. Additionally, we identified that management did not design and maintain user access controls to adequately restrict user and privileged access to financial applications, programs, and data to appropriate company personnel, which is also considered a material weakness.

A material weakness is defined as a deficiency, or a combination of deficiencies, in internal control over financial reporting such that there is a reasonable possibility that a material misstatement of our annual or interim financial statements will not be prevented or detected on a timely basis.

As of September 30, 2025, we have initiated steps toward remediation of the issues. The material weaknesses cannot be considered completely remediated until the applicable controls have operated for a sufficient period of time and management has concluded, through testing, that these controls are operating effectively. We expect this to take through 2025 and beyond as necessary.

In response to the identified material weaknesses, we have implemented and will continue to implement additional corrective actions to enhance the effectiveness of our controls and ensure that they are operating as intended.

Such measures include:

During the fiscal period covered by this report, our management, with the participation of our Chief Executive Officer and Chief Financial Officer, carried out an evaluation of the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) of the Exchange Act). Based on such evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that, as of September 30, 2025, our disclosure controls and procedures were effective to ensure that information required to be disclosed by us in reports that we file or submit under the Exchange Act are recorded, processed, summarized and reported within the required time periods and are designed to ensure that information required to be disclosed in our reports is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer as appropriate, to allow timely decisions regarding required disclosure.

Changes in Internal Control Over Financial Reporting

Except as disclosed above, there were no changes that occurred during the three months ended September 30, 2025, that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.