Results of Operations and Financial Condition. On August 6, 2026 , Century Aluminum Company (the "Company") issued a press release announcing its results of operations for quarter ended June 30, 2026. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Thursday, August 6, 2026 , at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the Company’s website, located at www.ce…

Results of Operations and Financial Condition. On May 7, 2026 , Century Aluminum Company (the "Company") issued a press release announcing its results of operations for quarter ended March 31, 2026. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Thursday, May 7, 2026 , at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the Company’s website, located at www.century…

Non-Reliance on Previously Issued Financial Statements or a Related Audit Report or Completed Interim Review. (a) Century Aluminum Company (the “Company”) has recently changed the manner in which it accounts for certain assets and related asset retirement liabilities and other liabilities in connection with its Jamalco joint venture (the “Jamalco Production Assets”). Since its acquisition of a 55% interest in Jamalco in May 2023, the Company has been accounting for the Jamalco Production Asse…

Results of Operations and Financial Condition. On February 19, 2026 , Century Aluminum Company (the "Company") issued a press release announcing its results of operations for its fourth quarter and full year ended December 31, 2025. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Thursday , February 19, 2026 , at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the…

Completion of Acquisition or Disposition of Assets. On February 2, 2026, CAKY completed the sale of the Property to the Purchaser pursuant to the terms of the Purchase and Sale Agreement. The information set forth under the subheading “Purchase and Sale Agreement” in

Entry into a Material Definitive Agreement. Purchase and Sale Agreement On February 2, 2026, Century Aluminum of Kentucky General Partnership, a Kentucky general partnership (“CAKY”) and Justified DataPower LLC, a Delaware limited liability company (“Purchaser”), entered into an agreement of purchase and sale (the “Purchase and Sale Agreement”), pursuant to which, among other things, CAKY sold certain real property comprised of approximately 750 acres and commonly known as 1627 State Route 35…

Results of Operations and Financial Condition. On November 6, 2025, Century Aluminum Company (the "Company") issued a press release announcing its results of operations for quarter ended September 30, 2025. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Thursday, November 6, 2025, at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the Company’s website, located at…

in the EDGAR submission header. This Amendment is being filed through EDGAR to reference the correct Form 8-K Item Numbers (Items 2.02 and 9.01) in the EDGAR submission header. There are no changes to the Original Filing itself (which referenced the correct Item numbers) other than the date of this Amendment. Except as summarized above, this Amendment continues to speak as of the date of the Original Filing and does not reflect events occurring after the date of the Original Filing or modify…

Results of Operations and Financial Condition. On November 6, 2025 , Century Aluminum Company (the "Company") issued a press release announcing its results of operations for quarter ended September 30, 2025. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Thursday, November 6, 2025 , at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the Company’s website, located…

Results of Operations and Financial Condition. On August 7, 2025 , Century Aluminum Company (the "Company") issued a press release announcing its results of operations for quarter ended June 30, 2025. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Wednesday, August 7, 2025 , at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the Company’s website, located at www.c…

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

below, to repay borrowings under Century’s credit facilities and to pay fees and expenses relating to the offering of the Notes. The foregoing summary of the Indenture, the Security Agreement and the Collateral Agreement does not purport to be complete and is qualified in its entirety by the terms of the Indenture, the Security Agreement and the Collateral Agreement, copies of which are attached hereto as Exhibits 4.1, 10.1 and 10.2, respectively, and incorporated by reference herein. Fifth A…

Entry into a Material Definitive Agreement. Senior Secured Notes due 2032 On July 22, 2025, Century Aluminum Company (the “ Company ”) completed its previously announced offering of $400 million aggregate principal amount of 6.875% Senior Secured Notes due 2032 (the “ Notes ”). The Notes were issued pursuant to an indenture, dated as of July 22, 2025 (the “ Indenture ”), by and among the Company, the guarantor subsidiaries of the Company named therein (the “ Guarantors ”) and Wilmington Trust…

Results of Operations and Financial Condition. On May 7, 2025 , Century Aluminum Company (the "Company") issued a press release announcing its results of operations for quarter ended March 31, 2025. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Wednesday, May 7, 2025 , at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the Company’s website, located at www.centur…

CFO — Gerald Bialek: The filing discloses a planned transition where the CFO is succeeded by an internal promotion, indicating an orderly succession rather than a sudden loss of leadership.

Results of Operations and Financial Condition. On February 20, 2025 , Century Aluminum Company (the "Company") issued a press release announcing its results of operations for its fourth quarter and full year ended December 31, 2024. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Thursday , February 20, 2025 , at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the…

Chief Information Officer — Rob Hoffman: Rob Hoffman was promoted to SVP, CIO, and CAO, assuming the principal accounting officer role following the departure of the former officer.

Principal Accounting Officer — Theresa Brainerd: The filing discloses an internal succession where the Global Corporate Controller assumed the Principal Accounting Officer role, while the previous holder retained a C-suite position as CIO.

Results of Operations and Financial Condition. On November 4, 2024, Century Aluminum Company (the "Company") issued a press release announcing its results of operations for quarter ended September 30, 2024. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Monday, November 4, 2024, at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the Company’s website, located at w…

Results of Operations and Financial Condition. On August 8, 2024, Century Aluminum Company (the "Company") issued a press release announcing its results of operations for quarter ended June 30, 2024. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Thursday, August 8, 2024, at 5:00 p.m. Eastern Time. The earnings call will be webcast live on the Company’s website, located at www.cent…

Results of Operations and Financial Condition. On May 1, 2024, Century Aluminum Company (the "Company") issued a press release announcing its results of operations for quarter ended March 31, 2024. A copy of the Company’s press release is attached as Exhibit 99.1 and is incorporated herein by reference. The Company will hold a follow-up conference call on Wednesday, May 1, 2024, at 11:00 a.m. Eastern Time. The earnings call will be webcast live on the Company’s website, located at www.century…