Mayville Engineering Company Inc

Evaluation of Disclosure Controls and Procedures

We maintain disclosure controls and procedures that are designed to provide reasonable assurance that information required to be disclosed in the reports we file or submit under the Securities Exchange Act of 1934, as amended (the Exchange Act), is recorded, processed, summarized and reported within the time periods specified in the rules and forms of the SEC, and that such information is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, to allow for timely decisions regarding required disclosure. In designing disclosure controls and procedures, our management necessarily was required to apply its judgment in evaluating the cost-benefit relationship of possible disclosure controls and procedures. The design of any disclosure controls and procedures also is based in part upon certain assumptions about the likelihood of future events, and there can be no assurance that any design will succeed in achieving its stated goals under all potential future conditions. Any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired objectives.

As of December 31, 2024, we carried out an evaluation, under the supervision and with the participation of our Chief Executive Officer and Chief Financial Officer, 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) under the Exchange Act). Based on this evaluation, our Chief Executive Officer and Chief Financial Officer concluded that, due to the identification of the material weakness in our internal control over financial reporting as described below, our disclosure controls and procedures were not effective as of December 31, 2024. Notwithstanding the material weakness in our internal control over financial reporting, management believes the consolidated financial statements included in this Annual Report on Form 10-K fairly present, in all material respects, our financial position, results of operations and cash flows as of the dates presented, and for the periods ended on such dates, in conformity with accounting principles generally accepted in the United States of America (GAAP).

Management’s Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Rules 13a-15(f) and 15d-15(f) of the Exchange Act. Internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with GAAP. Our internal control over financial reporting includes those policies and procedures that: (i) pertain to the maintenance of records that in reasonable detail accurately and fairly reflect the transactions and dispositions of our assets, (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with GAAP, and that our receipts and expenditures are being made only in accordance with authorizations of our management and directors, and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of our assets that could have a material effect on our financial statements.

Our management, under the supervision of our Chief Executive Officer and Chief Financial Officer, evaluated the effectiveness of our internal control over financial reporting as of the end of the most recent fiscal year, December 31, 2024, utilizing the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission ("COSO") in theInternal Control-Integrated Framework (2013). Based on this evaluation, our management concluded that we did not maintain effective internal control over financial reporting as of December 31, 2024 due to the material weakness described below.

A material weakness is 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 consolidated financial statements will not be prevented or detected on a timely basis.

Management identified deficiencies in the design and operating effectiveness of internal control over financial reporting related to the review and approval of journal entries that constitutes a material weakness.

Deloitte & Touche LLP, our independent registered public accounting firm, has issued an attestation report on our internal control over financial reporting as of December 31, 2024, which follows below.

Remediation Efforts to Address the Material Weakness

We are committed to maintaining a strong system of internal control and will undertake remediation efforts to improve our internal controls. With the oversight of senior management, subsequent to December 31, 2024, a plan to remediate the underlying cause of the material weakness and improve the operating effectiveness of our internal control over financial reporting has been developed and is being implemented. Specifically, the following remediation efforts are planned or ongoing to ensure adequate review and approval of journal entries, including:

Changes in Internal Control Over Financial Reporting

Except for the identified material weakness, there were no changes in our internal control over financial reporting that occurred during the quarter ended December 31, 2024, that materially affected, or were reasonably likely to materially affect, our internal control over financial reporting.