KAISER ALUMINUM CORP

The audit committee charter requires the audit committee to undertake a variety of activities designed to assist our board of directors in fulfilling its oversight role regarding our independent registered public accounting firm's independence, our financial reporting process, our internal control over financial reporting and our compliance with applicable laws, rules and regulations. These requirements are briefly summarized under "Corporate Governance - Board Committees - Audit Committee" above. The audit committee charter also provides that the independent registered public accounting firm is ultimately accountable to our board of directors and the audit committee, not our management.

Our internal accountants prepare our consolidated financial statements and our independent registered public accounting firm is responsible for auditing those financial statements. The audit committee oversees the financial reporting processes implemented by our management but does not conduct any auditing or accounting reviews. The members of the audit committee are not company employees. Instead, the audit committee relies, without independent verification, on our management's representation that the financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America and on the report of our independent registered public accounting firm on our financial statements. The audit committee's oversight does not provide it with an independent basis for determining whether our management has maintained appropriate accounting and financial reporting principles or policies or appropriate internal controls and procedures designed to assure compliance with accounting standards and applicable laws and regulations. Furthermore, the audit committee's discussions with our management and its accountants do not ensure that the financial statements are presented in accordance with accounting principles generally accepted in the United States of America or that the audit of our financial statements has been carried out in accordance with auditing standards of the Public Company Accounting Oversight Board or that our independent registered public accounting firm is in fact "independent."

We have engaged Deloitte & Touche LLP as our independent registered public accounting firm to audit and report to our stockholders on our financial statements for 2025 and the effectiveness of our internal control over financial reporting as of December 31, 2025. The audit committee reviews annually the independence and performance of Deloitte & Touche LLP in connection with the audit committee's determination of whether to retain Deloitte & Touche LLP or engage another firm as our independent registered public accounting firm. In the course of these reviews, the audit committee considers, among other things:

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the historical and recent performance of Deloitte & Touche LLP on our company's integrated audit;

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an analysis of known risks and significant proceedings involving Deloitte & Touche LLP, if any;

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external data relating to the audit quality and performance, including recent Public Company Accounting Oversight Board reports on Deloitte & Touche LLP and its member firms;

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the appropriateness of Deloitte & Touche LLP's fee;

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Deloitte & Touche LLP's tenure as our independent registered public accounting firm and its familiarity with our operations and businesses, accounting policies and practices and internal control over financial reporting;

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Deloitte & Touche LLP's capability and expertise in relation to the breadth and complexity of our operations; and

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Deloitte & Touche LLP's independence.

Based on its review the audit committee believes that Deloitte & Touche LLP is independent and that it is in the best interests of our company and our stockholders to retain Deloitte & Touche LLP to serve as our independent registered public accounting firm for 2025.

In accordance with rules of the SEC and Deloitte & Touche LLP's policies, audit partners are subject to rotation requirements to limit the number of consecutive years an individual partner may provide service to our company. For lead audit and engagement quality control review partners, the maximum number of consecutive years of service in that capacity is five years. In addition to ensuring the regular rotation of the lead audit partner as required by law, the audit committee is involved in the selection of, and reviews and evaluates, the lead audit partner. The process for approval of the lead audit partner for our company pursuant to this rotation policy involves a meeting between the chair of the audit committee and the candidate for the role, as well as discussion by the full committee and with management. The lead audit partner was rotated in 2023.

The audit committee has discussed with management and Deloitte & Touche LLP significant accounting policies applied by us in our financial statements as well as a critical audit matter, revenue recognition. For a more detailed discussion of these accounting items, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations" in our Annual Report on Form 10-K for the year ended December 31, 2024. During the year ended December 31, 2024, there were no disagreements with Deloitte & Touche LLP on any matter of accounting principle or practice, financial statement disclosure or auditing scope or procedure, which, if not resolved to the satisfaction of Deloitte & Touche LLP, would have caused them to make a reference to the subject matter of the disagreement in connection with its reports.

The audit committee reviewed and discussed the Company's audited financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2024 with our management. The audit committee has also discussed with our independent registered public accounting firm the matters required to be discussed pursuant to the applicable requirements of the Public Company Accounting Oversight Board and the SEC.

The audit committee also received and reviewed the written disclosures and the letter from Deloitte & Touche LLP required by applicable requirements of the Public Company Accounting Oversight Board regarding the independent accountant's communications with the audit committee concerning independence and has discussed with Deloitte & Touche LLP its independence.

The audit committee discussed with our internal accountants and Deloitte & Touche LLP the overall scope and plans for their respective audits. The audit committee meets with management, our internal accountants, and our independent accountants periodically in separate private sessions to discuss any matter that the audit committee, our management, our internal accountants, the independent accountants or such other persons believe should be discussed privately.

Based on the review and discussions referred to above, the audit committee recommended to our board of directors that our audited financial statements be included in our Annual Report on Form 10-K for the year ended December 31, 2024, as filed with the SEC.

The audit committee considered whether, and concluded that, the provision by Deloitte & Touche LLP of the services for which we paid the amounts set forth under "Independent Public Accountants - Tax Fees" and "Independent Public Accountants - All Other Fees" below is compatible with maintaining the independence of Deloitte & Touche LLP.

This report is submitted by the members of the audit committee of the board of directors:

Audit Committee

Lauralee E. Martin (Chair)

Kimberly T. Glas

Teresa M. Sebastian

Brett E. Wilcox

Kevin W. Williams

This Audit Committee Report does not constitute soliciting material and shall not be deemed filed or incorporated by reference into any other filing made by us under the Securities Act or the Exchange Act, except to the extent that we specifically incorporate this Audit Committee Report by reference therein.