Change in Certifying Accountants - Form 8-K

(a) Dismissal of Previous Independent Registered Public Accounting Firm

On February 29, 2024, the Audit Committee (the "Audit Committee") of the Board of Directors of Codexis, Inc. (the "Company") dismissed BDO USA, P.C. ("BDO") as the Company's independent registered public accounting firm.

The reports of BDO on the consolidated financial statements of the Company as of and for the fiscal years ended December 31, 2023 and 2022 did not contain an adverse opinion or a disclaimer of opinion and were not qualified or modified as to uncertainty, audit scope, or accounting principles.

During the fiscal years ended December 31, 2023 and 2022 and during the interim period through February 29, 2024, there were (i) no disagreements (as defined in Item 304(a)(1)(iv) of Regulation S-Kand the related instructions) between the Company and BDO on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure, any of which, if not resolved to BDO's satisfaction, would have caused BDO to make reference thereto in their reports, and (ii) no "reportable events" (as defined in Item 304(a)(1)(v) of Regulation S-Kand the related instructions), except that a material weakness in internal control over financial reporting was identified in the first quarter of 2022 related to management's controls over the revenue recognition process in the three months ended March 31, 2022, as described in Item 4 of the Company's Quarterly Reports on Form 10-Qfor the quarters ended March 31, 2022, June 30, 2022 and September 30, 2022. As reported in Part II, Item 9A of the Company's Annual Report on Form 10-Kfor the fiscal year ended December 31, 2022, management concluded that the material weakness was remediated during the fourth quarter of 2022 and that, as of December 31, 2022, the Company's internal control over financial reporting was effective.

The Company provided BDO with a copy of the disclosures it is making in this Current Report on Form 8-Kand requested that BDO furnish the Company with a letter addressed to the Securities and Exchange Commission stating whether it agrees with the statements made herein and, if not, stating the respects in which it does not agree. A copy of such letter provided by BDO, dated March 5, 2024, is filed as Exhibit 16.1 to this Current Report on Form 8-K.

(b) Appointment of New Independent Registered Public Accounting Firm

On February 29, 2024, the Audit Committee approved the engagement of KPMG LLP ("KPMG") as the Company's independent registered public accounting firm for the fiscal year ending December 31, 2024. During the Company's two most recent fiscal years ended December 31, 2023 and 2022 and during the interim period through February 29, 2024 neither the Company nor anyone acting on its behalf consulted with KPMG regarding (i) the application of accounting principles to a specific transaction, either completed or proposed, or the type of audit opinion that might be rendered on the Company's financial statements or the effectiveness of internal control over financial reporting, and neither a written report nor oral advice was provided to the Company that KPMG concluded was an important factor considered by the Company in reaching a decision as to any accounting, auditing, or financial reporting issue, or (ii) any matter that was the subject of a disagreement (as defined in Item 304(a)(1)(iv) of Regulation S-Kand the related instructions) or a reportable event (as defined in Item 304(a)(1)(v) of Regulation S-Kand the related instructions).