Kaiser Aluminum Corporation in connection with its 2022 annual meeting of stockholders on June 2, 2022 (the “2022 Annual Meeting”), after more than 15 years of leadership and dedicated service on the Company's board of directors (the “Board”), including as a past or present member of the Company's audit, compensation, executive and nominating and corporate governance committees, Thomas M. Van Leeuwen is not standing for re-election as a Class I Director of the Company upon the expiration of his current term, which expires at the 2022 Annual Meeting. In connection with his nomination, on April 26, 2022, Mr. Harvey notified the Board of his intention to resign as a Class II Director, contingent upon his election as a Class I Director at the 2022 Annual Meeting. Mr. Harvey's decision to resign as a Class II Director is solely to facilitate his election as a Class I Director at the 2022 Annual Meeting.