Financial Analysis

6. Commitments and Contingencies Commitments. We have a variety of financial commitments, including purchase agreements, forward foreign exchange and forward sales contracts, indebtedness and letters of credit (see Note 4 and Note 5). Environmental Contingencies. We are subject to several environmental laws and regulations, potential fines or penalties assessed for alleged breaches of such laws and regulations, and potential claims based upon such laws and regulations. We are also subject to legacy environmental contingencies related to activities that occurred at our operating facilities prior to July 6, 2006, which represent the majority of our environmental accrua ls of $ 17.6 million as of June 30, 2026. This accrual represents our undiscounted estimate of costs reasonably expected to be incurred based on current laws and regulations, available facts, existing technologies, and our assessment of the likely remediation actions to be taken. Based on approved and proposed remediation action plans for the various facilities, we expect that the implementation and ongoing monitoring could occur over a period of 30 or more years. As additional facts are developed, feasibility studies are completed, remediation plans are modified, necessary regulatory approvals for the implementation of remediation are obtained, alternative technologies are developed and/or other factors change, there may be revisions to managements estimates, and actual costs may exceed the current environmental …

CommitmentsAndContingenciesDisclosureTextBlock · excerpt; the full note is in the filing

5. Debt and Credit Facility Senior Notes At June 30, 2026 and December 31, 2025 , we had outstanding fixed-rate unsecured Senior Notes with varying maturity dates. The stated interest rates and aggregate principal amounts of such Senior Notes were, respectively: (i) 4.50 % and $ 550.0 million (4.50% Senior Notes) and (ii) 5.875 % and $ 500.0 million (5.875% Senior Notes). Our Senior Notes do not require us to make any mandatory redemptions or sinking fund payments. The following table summarizes key details of our Senior Notes: Outstanding Issuance Date Maturity Effective Interest Rate As of June 30, 2026 As of December 31, 2025 4.50 % Senior Notes May 2021 June 2031 4.7 % $ 550.0 $ 550.0 5.875 % Senior Notes November 2025 March 2034 6.1 % 500.0 500.0 Total debt 1,050.0 1,050.0 Unamortized issuance costs ( 11.7 ) ( 12.7 ) Total carrying amount $ 1,038.3 $ 1,037.3 The following table presents the fair value of our outstanding Senior Notes, which are Level 1 liabilities: As of June 30, 2026 As of December 31, 2025 4.50% Senior Notes $ 526.5 $ 531.4 5.875% Senior Notes $ 494.8 $ 501.6 Revolving Credit Facility In October 2019, we entered into a Revolving Credit Facility. Joining us as borrowers under the Revolving Credit Facility are four of our wholly owned domestic operating subsidiaries: (i) Kaiser Aluminum Investments Company; (ii) Kaiser Aluminum Fabricated Products, LLC; (iii) Kaiser Aluminum Washington, LLC; and (iv) Kaiser Aluminum Warrick, LLC. As amended in October 202 …

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9. Income Tax Matters The following table presents the income tax provision by region: Quarter Ended June 30, Six Months Ended June 30, 2026 2025 2026 2025 Domestic $ ( 28.9 ) $ ( 6.0 ) $ ( 48.2 ) $ ( 12.6 ) Foreign ( 0.6 ) ( 0.7 ) ( 1.2 ) ( 1.3 ) Total $ ( 29.5 ) $ ( 6.7 ) $ ( 49.4 ) $ ( 13.9 ) The income tax provision for the quarters ended June 30, 2026 and June 30, 2025 was $ 29.5 million and $ 6.7 million , respectively, reflecting an effective tax rate of 23 % and 22 %, respectively. There was no material difference between the effective tax rate and the blended statutory tax rate for the quarters ended June 30, 2026 and 2025. The income tax provision for the six months ended June 30, 2026 and June 30, 2025 w as $ 49.4 million a nd $ 13.9 million , respectively, reflecting an effective tax rate of 24 % and 24 %, respectively. There was no material difference between the effective tax rate and the blended statutory tax rate for the six months ended June 30, 2026 and 2025. Our gross unrecognized benefits relating to uncertain tax positions wer e $ 8.1 million a nd $ 7.4 million at June 30, 2026 and December 31, 2025 , respectively. If recognized, these amounts would be reflected in our income tax provision and affect our effective tax rate.

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Adoption of New Accounting Pronouncements Government Grants. In December 2025, the Financial Accounting Standards Board (FASB) issued ASU No. 2025-10 (ASU 2025-10), Government Grants (Topic 832): Accounting for Government Grants Received by Business Entities, to establish authoritative guidance on the accounting for government grants received by business entities. We early adopted ASU 2025-10 during the quarter ended June 30, 2026 , using the full retrospective transition method. The adoption of ASU 2025-10 did no t have a material impact on our consolidated financial statements for all periods presented. …

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3. Employee Benefits Deferred Compensation Plan Assets of our deferred compensation plan are included in Other assets. Such assets, representing diversified investment funds in registered investment companies, are classified within Level 1 of the fair value hierarchy and are measured and recorded at fair value based on their quoted market prices. These assets are accounted for as equity investments, with changes in fair value recorded within Other income, net (see Note 8). Offsetting liabilities relating to the deferred compensation plan are included in Other accrued liabilities and Long-term liabilities. Short-Term Incentive Plans As of June 30, 2026, we had a liability of $ 18.7 million recorded within Accrued salaries, wages and related expenses for estimated probable future payments under the 2026 short-term incentive plans. Postretirement and Postemployment Benefit Plans The following table presents the total expense related to all postretirement and postemployment benefit plans: Quarter Ended June 30, Six Months Ended June 30, 2026 2025 2026 2025 Defined contribution plans 1 $ 4.5 $ 4.6 $ 10.5 $ 10.6 Deferred compensation plan 2 0.9 0.4 1.0 0.6 Multiemployer pension plans 1 1.6 1.6 3.1 3.1 Net periodic postretirement and postemployment benefit cost relating to defined benefit plans 3 2.1 2.5 4.2 4.8 Total $ 9.1 $ 9.1 $ 18.8 $ 19.1 1. Substantially all of these charges related to employee benefits are in COGS with the remaining balance in Selling, general, administrative …

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12. Business, Product, and Geographical Area Information Our primary line of business is the production of semi-fabricated specialty aluminum mill products, such as plate and sheet, bare and coated coils, and extruded and drawn products, primarily used in our Aero/HS Products, Packaging, GE Products, and Automotive Extrusions end markets. We operate production facilities in the United States and Canada. We have one operating and reportable segment. Our determination that we operate as a single segment is consistent with the financial information regularly viewed by the chief operating decision maker (CODM) to evaluate performance and make decisions regarding resource allocation. The CODM uses Net income to measure segment profitability in deciding whether to reinvest profits into the segment or into other parts of the entity, such as for acquisitions or to pay dividends. The following table presents the significant segment expenses that are provided to the CODM: Quarter Ended June 30, Six Months Ended June 30, 2026 2025 2026 2025 Net sales $ 1,256.6 $ 823.1 $ 2,363.4 $ 1,600.5 Less: Cost of products sold, excluding depreciation and amortization Hedged cost of alloyed metal 1 819.6 448.9 1,522.0 863.1 Manufacturing costs 2 151.5 191.9 313.7 373.7 Plant overhead 3 47.9 44.0 95.2 90.1 Freight costs 28.0 21.2 50.3 42.0 Other cost of products sold 4 10.6 16.8 19.6 27.3 Depreciation and amortization 29.6 29.6 60.0 59.6 Selling, general, administrative, research and development Rese …

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13. Subsequent Events Dividend Declaration. O n July 13, 2026 , we announced that our Board of Directors declared a quarterly cash dividend of $ 0.77 per common share. As such, we expect to pay approximately $ 12.8 million (including dividend equivalents) on or about August 14, 2026 to stockholders of record and the holders of certain restricted stock units at the close of business on July 24, 2026 .

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