CEO — Fred Stephan: The filing announces the planned succession of an external hire (Fred Stephan) to replace the current CEO as part of a structured transition, rather than an unexpected departure.

The information in Item 2.02, including Exhibit 99.1, of this Current Report on Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and shall not be deemed incorporated by reference into any filing by the Company under the Securities Act of 1933, as amended, or the Exchange Act, unless specifically identified therein as being incorporated therein…

Other Events. On July 13, 2026, Kaiser Aluminum Corporation announced that its board of directors declared a quarterly cash dividend on its common stock of $0.77 per share. The dividend will be payable on August 14, 2026 to stockholders of record as of the close of business on July 24, 2026. A copy of the press release is attached hereto as Exhibit 99.1. The information contained in the press release shall not be deemed to be "filed" for purposes of Section 18 of the Securities Exchange Act o…

The filing describes an amendment to the equity and incentive compensation plan.

The information in Item 2.02, including Exhibit 99.1, of this Current Report on Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and shall not be deemed incorporated by reference into any filing by the Company under the Securities Act of 1933, as amended, or the Exchange Act, unless specifically identified therein as being incorporated therein…

Other Events. On April 13, 2026, Kaiser Aluminum Corporation announced that its board of directors declared a quarterly cash dividend on its common stock of $0.77 per share. The dividend will be payable on May 15, 2026 to stockholders of record as of the close of business on April 24, 2026. A copy of the press release is attached hereto as Exhibit 99.1. The information contained in the press release shall not be deemed to be "filed" for purposes of Section 18 of the Securities Exchange Act of…

The information in Item 2.02, including Exhibit 99.1, of this Current Report on Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and shall not be deemed incorporated by reference into any filing by the Company under the Securities Act of 1933, as amended, or the Exchange Act, unless specifically identified therein as being incorporated therein…

Other Events. On January 13, 2026, Kaiser Aluminum Corporation announced that its board of directors declared a quarterly cash dividend on its common stock of $0.77 per share. The dividend will be payable on February 13, 2026 to stockholders of record as of the close of business on January 23, 2026. A copy of the press release is attached hereto as Exhibit 99.1. The information contained in the press release shall not be deemed to be "filed" for purposes of Section 18 of the Securities Exchan…

Executive Vice President — Blain A. Tiffany: The filing discloses a planned succession where the retiring EVP transitions to an advisor role while a successor is appointed, indicating an orderly transition rather than a sudden loss of leadership.

Executive Vice President — Jason D. Walsh: The EVP is taking a health leave with an immediate internal successor appointed, indicating an orderly transition rather than a sudden loss of leadership.

Entry into a Material Definitive Agreement. On November 5, 2025, Kaiser Aluminum Corporation (the “Company”) issued $500,000,000 aggregate principal amount of its 5.875% Senior Notes due 2034 (the “Notes”) pursuant to an indenture, dated November 5, 2025 (the “Indenture”), among the Company, the subsidiary guarantors party thereto (the “Guarantors”) and Computershare Trust Company, N.A., as trustee (the “Trustee”). The Notes were offered and sold either to persons reasonably believed to be “q…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth under

Other Events. On October 27, 2025, Kaiser Aluminum Corporation (the “Company”) issued a press release announcing its intention to offer $500.0 million in aggregate principal amount of senior notes due 2034 (the “New Notes”), in a private transaction that is exempt from the registration requirements of the Securities Act of 1933. The consummation of the offering of New Notes is subject to market conditions and there can be no assurance that the offering of New Notes will be consummated. The Co…

Other Events. On October 27, 2025, Kaiser Aluminum Corporation (the “Company”) issued a press release announcing that it has priced $500.0 million in aggregate principal amount of 5.875% senior notes due 2034 (the “New Notes”), in a private transaction that is exempt from the registration requirements of the Securities Act of 1933. The consummation of the offering of New Notes is expected to be completed on November 5, 2025, subject to customary closing conditions. The Company intends to use…

The information in Item 2.02, including Exhibit 99.1, of this Current Report on Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and shall not be deemed incorporated by reference into any filing by the Company under the Securities Act of 1933, as amended, or the Exchange Act, unless specifically identified therein as being incorporated therein…

Entry into a Material Definitive Agreement. On October 14, 2025, Kaiser Aluminum Corporation (the “Company”) and certain subsidiaries of the Company (collectively with the Company, the “Borrowers”) entered into the Amendment No. 5 to Credit Agreement and Loan Documents with Wells Fargo Bank, National Association (“Wells Fargo”), as administrative agent, and the other financial institutions party thereto (the “Amendment”), which modifies the Credit Agreement dated as of October 30, 2019 (as am…

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth under

Other Events. On October 14, 2025, Kaiser Aluminum Corporation announced that its board of directors declared a quarterly cash dividend on its common stock of $0.77 per share. The dividend will be payable on November 14, 2025 to stockholders of record as of the close of business on October 24, 2025. A copy of the press release is attached hereto as Exhibit 99.1. The information contained in the press release shall not be deemed to be "filed" for purposes of Section 18 of the Securities Exchan…

Director — James D. Hoffman: The filing discloses the appointment of a new independent director to the board, which is a routine governance event and not a departure of a senior executive.

Director — Kevin W. Williams: A director resigned without disagreement, which is a standard board turnover event with low materiality compared to C-suite departures.

The information in Item 2.02, including Exhibit 99.1, of this Current Report on Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and shall not be deemed incorporated by reference into any filing by the Company under the Securities Act of 1933, as amended, or the Exchange Act, unless specifically identified therein as being incorporated therein…

Other Events. On July 15, 2025, Kaiser Aluminum Corporation announced that its board of directors declared a quarterly cash dividend on its common stock of $0.77 per share. The dividend will be payable on August 15, 2025 to stockholders of record as of the close of business on July 25, 2025. A copy of the press release is attached hereto as Exhibit 99.1. The information contained in the press release shall not be deemed to be "filed" for purposes of Section 18 of the Securities Exchange Act o…

Director — Glenda J. Minor: The filing discloses the appointment of a new outside director, which is a routine board composition change and not a departure of a senior executive.

The information in Item 2.02, including Exhibit 99.1, of this Current Report on Form 8-K shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and shall not be deemed incorporated by reference into any filing by the Company under the Securities Act of 1933, as amended, or the Exchange Act, unless specifically identified therein as being incorporated therein…

Other Events. On April 15, 2025, Kaiser Aluminum Corporation announced that its board of directors declared a quarterly cash dividend on its common stock of $0.77 per share. The dividend will be payable on May 15, 2025 to stockholders of record as of the close of business on April 25, 2025. A copy of the press release is attached hereto as Exhibit 99.1. The information contained in the press release shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of…