Business and Basis of Presentation (Policies)	3 Months Ended
Mar. 31, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). In management’s opinion, all material adjustments necessary for a fair statement of the financial condition, results of operations and cash flows of the Company, including its consolidated variable interest entities (VIEs), are reflected in the periods presented and are of a normal, recurring nature. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. These unaudited interim condensed consolidated financial statements are as of March 31, 2026 and cover the three-month period ended March 31, 2026 (first quarter 2026) and the three-month period ended March 31, 2025 (first quarter 2025). Certain financial information that is normally included in annual financial statements prepared in accordance with GAAP, but is not required for interim reporting purposes, has been condensed or omitted. The year-end condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by GAAP. Certain prior year balances have been reclassified to conform to the current period’s presentation.
Consolidation	The unaudited interim condensed consolidated financial statements include the accounts of AGL, its direct and indirect subsidiaries, and its consolidated VIEs. See Note 10. Variable Interest Entities. Intercompany accounts and transactions between and among all consolidated entities have been eliminated. All amounts are reported in U.S. dollars, unless otherwise specified.
Recent Accounting Standards Not Yet Adopted	Recent Accounting Standards Not Yet Adopted In November 2024, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40). The amendments in this ASU require disclosure about specific expense categories, including employee compensation, depreciation and intangible asset amortization, in the notes to the financial statements at interim and annual reporting periods. This ASU is effective in fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. Prospective application is required, and retrospective application is permitted. The Company is evaluating when and how it will adopt this ASU and the effect that the amendments in this ASU may have on its expense disclosures. In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. This ASU updates the capitalization guidance for internal-use software development costs by removing all references to software development project stages and providing new guidance requiring an entity to start capitalizing when both of the following occur: (i) management has authorized and committed to funding a software project; and (ii) it is probable that the project will be completed and the software will be used to perform the function intended. This ASU is effective for fiscal years beginning after December 15, 2027, and interim periods within those fiscal years, with early adoption permitted. This ASU allows entities to adopt the new guidance prospectively, retrospectively or with a modified transition. The Company is evaluating when and how it will adopt this ASU and the effect it may have on its consolidated financial statements. In December 2025, the FASB issued ASU 2025-11, Interim Reporting (Topic 270): Narrow-Scope Improvements. This ASU is intended to improve the navigability of guidance in ASC 270, Interim Reporting, and clarify when it applies. The ASU also provides additional guidance on what disclosures should be provided in interim reporting periods. This ASU is effective for fiscal years beginning after December 15, 2027, including interim periods within those fiscal years, and permits prospective or full retrospective adoption. Early adoption is permitted. The Company is evaluating when and how it will adopt this ASU and the effect it may have on its consolidated financial statements and related disclosures.
Fair Value Measurement	The Company carries a significant portion of its assets and liabilities at fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., exit or transfer price). The price represents the price available in the principal market for the asset or liability. If there is no principal market, then the price is based on a hypothetical market that maximizes the value received for an asset or minimizes the amount paid for a liability (i.e., the most advantageous market). Fair value is based on quoted market prices, where available. If listed prices or quotes are not available, fair value is based on either (i) internally developed models that primarily use, as inputs, market-based or independently sourced market parameters (including, but not limited to, yield curves, interest rates and debt prices) or (ii) discounted cash flows using a third party’s proprietary pricing models. In addition to market information, when applicable, the models also incorporate transaction details, such as the instrument’s maturity, and contractual features that reduce the Company’s credit exposure (e.g., collateral rights). Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments include amounts to reflect counterparty credit quality, the Company’s creditworthiness and constraints on liquidity. As markets and products develop and the pricing transparency for certain products changes, the Company may refine its methodologies and assumptions. During first quarter 2026, no changes were made to the Company’s valuation models that had (or are expected to have) a material impact on the Company’s condensed consolidated balance sheets, statements of operations and comprehensive income. The Company’s valuation methods produce fair values that may not be indicative of net realizable value or future fair values. The use of different methodologies or assumptions to determine fair value of certain financial instruments could result in a materially different estimate of fair value at the reporting date. The categorization within the fair value hierarchy is determined based on whether the inputs to valuation techniques used to measure fair value are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect Company estimates of market assumptions. The fair value hierarchy prioritizes model inputs into three broad levels, with Level 1 being the highest and Level 3 the lowest. The categorization, of an asset or liability, within the hierarchy is based on the lowest level of significant input to its valuation. Level 1—Quoted prices for identical instruments in active markets. The Company generally defines an active market as a market in which trading occurs at significant volumes. Active markets generally are more liquid and have a lower bid-ask spread than an inactive market. Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and observable inputs other than quoted prices, such as interest rates or yield curves and other inputs derived from or corroborated by observable market inputs. Level 3—Model derived valuations in which one or more significant inputs or significant value drivers are unobservable. Financial instruments are considered Level 3 when their values are (i) determined using pricing models, discounted cash flow methodologies or similar techniques and (ii) at least one significant model assumption or input is unobservable. Level 3 financial instruments include those for which the determination of fair value requires significant management judgment or estimation. There was a transfer of fixed-maturity trading securities to Level 3 during first quarter 2026 as observable inputs were no longer available to the Company. There were no other transfers from or into Level 3 during the periods presented.
Derivatives	Accounting Policy The Company purchases swaps and forward contracts to manage foreign currency, interest rate and inflation exposure in its annuity reinsurance business. These derivative instruments are subject to a master netting arrangement, which creates a right of offset for amounts due to and due from a counterparty that is enforceable in the event of a default or bankruptcy. These derivatives are measured at fair value and reported on a gross basis in “other assets” or “other liabilities” on the condensed consolidated balance sheets, with changes in fair value reported in “fair value gains (losses) on derivatives” in the condensed consolidated statements of operations. The Company also evaluates its reinsurance contract terms to identify embedded derivatives. If (i) the embedded derivative is not clearly and closely related to the economic characteristics of the host reinsurance contract, (ii) the reinsurance contract is not subject to recurring fair value measurement, and (iii) a separate instrument with the same terms would qualify as a derivative, then the embedded derivative is bifurcated and measured at fair value. The Company identified an embedded derivative whereby the Company has a right to receive the total return on the assets supporting the funds withheld coinsurance arrangement related to the MYGA block of business. The fair value of this embedded derivative is included in “funds withheld” on the condensed consolidated balance sheets and the change in its fair value, which is based on the unrealized gains and losses of the underlying assets, is reported in “fair value gains (losses) on derivatives” in the condensed consolidated statements of operations.

Business and Basis of Presentation (Policies)

3 Months Ended

Mar. 31, 2026

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). In management’s opinion, all material adjustments

necessary for a fair statement of the financial condition, results of operations and cash flows of the Company, including its consolidated variable interest entities (VIEs), are reflected in the periods presented and are of a normal, recurring nature. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

These unaudited interim condensed consolidated financial statements are as of March 31, 2026 and cover the three-month period ended March 31, 2026 (first quarter 2026) and the three-month period ended March 31, 2025 (first quarter 2025). Certain financial information that is normally included in annual financial statements prepared in accordance with GAAP, but is not required for interim reporting purposes, has been condensed or omitted. The year-end condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by GAAP. Certain prior year balances have been reclassified to conform to the current period’s presentation.

Consolidation

The unaudited interim condensed consolidated financial statements include the accounts of AGL, its direct and indirect subsidiaries, and its consolidated VIEs. See Note 10. Variable Interest Entities. Intercompany accounts and transactions between and among all consolidated entities have been eliminated. All amounts are reported in U.S. dollars, unless otherwise specified.

Recent Accounting Standards Not Yet Adopted

In November 2024, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40). The amendments in this ASU require disclosure about specific expense categories, including employee compensation, depreciation and intangible asset amortization, in the notes to the financial statements at interim and annual reporting periods. This ASU is effective in fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. Prospective application is required, and retrospective application is permitted. The Company is evaluating when and how it will adopt this ASU and the effect that the amendments in this ASU may have on its expense disclosures.

In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. This ASU updates the capitalization guidance for internal-use software development costs by removing all references to software development project stages and providing new guidance requiring an entity to start capitalizing when both of the following occur: (i) management has authorized and committed to funding a software project; and (ii) it is probable that the project will be completed and the software will be used to perform the function intended. This ASU is effective for fiscal years beginning after December 15, 2027, and interim periods within those fiscal years, with early adoption permitted. This ASU allows entities to adopt the new guidance prospectively, retrospectively or with a modified transition. The Company is evaluating when and how it will adopt this ASU and the effect it may have on its consolidated financial statements.

In December 2025, the FASB issued ASU 2025-11, Interim Reporting (Topic 270): Narrow-Scope Improvements. This ASU is intended to improve the navigability of guidance in ASC 270, Interim Reporting, and clarify when it applies. The ASU also provides additional guidance on what disclosures should be provided in interim reporting periods. This ASU is effective for fiscal years beginning after December 15, 2027, including interim periods within those fiscal years, and permits prospective or full retrospective adoption. Early adoption is permitted. The Company is evaluating when and how it will adopt this ASU and the effect it may have on its consolidated financial statements and related disclosures.

Fair Value Measurement

The Company carries a significant portion of its assets and liabilities at fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., exit or transfer price). The price represents the price available in the principal market for the asset or liability. If there is no principal market, then the price is based on a hypothetical market that maximizes the value received for an asset or minimizes the amount paid for a liability (i.e., the most advantageous market).

Fair value is based on quoted market prices, where available. If listed prices or quotes are not available, fair value is based on either (i) internally developed models that primarily use, as inputs, market-based or independently sourced market parameters (including, but not limited to, yield curves, interest rates and debt prices) or (ii) discounted cash flows using a third party’s proprietary pricing models. In addition to market information, when applicable, the models also incorporate transaction details, such as the instrument’s maturity, and contractual features that reduce the Company’s credit exposure (e.g., collateral rights).

Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments include amounts to reflect counterparty credit quality, the Company’s creditworthiness and constraints on liquidity. As markets

and products develop and the pricing transparency for certain products changes, the Company may refine its methodologies and assumptions. During first quarter 2026, no changes were made to the Company’s valuation models that had (or are expected to have) a material impact on the Company’s condensed consolidated balance sheets, statements of operations and comprehensive income.

The Company’s valuation methods produce fair values that may not be indicative of net realizable value or future fair values. The use of different methodologies or assumptions to determine fair value of certain financial instruments could result in a materially different estimate of fair value at the reporting date.

The categorization within the fair value hierarchy is determined based on whether the inputs to valuation techniques used to measure fair value are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect Company estimates of market assumptions. The fair value hierarchy prioritizes model inputs into three broad levels, with Level 1 being the highest and Level 3 the lowest. The categorization, of an asset or liability, within the hierarchy is based on the lowest level of significant input to its valuation.

Level 1—Quoted prices for identical instruments in active markets. The Company generally defines an active market as a market in which trading occurs at significant volumes. Active markets generally are more liquid and have a lower bid-ask spread than an inactive market.

Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and observable inputs other than quoted prices, such as interest rates or yield curves and other inputs derived from or corroborated by observable market inputs.

Level 3—Model derived valuations in which one or more significant inputs or significant value drivers are unobservable. Financial instruments are considered Level 3 when their values are (i) determined using pricing models, discounted cash flow methodologies or similar techniques and (ii) at least one significant model assumption or input is unobservable. Level 3 financial instruments include those for which the determination of fair value requires significant management judgment or estimation.

There was a transfer of fixed-maturity trading securities to Level 3 during first quarter 2026 as observable inputs were no longer available to the Company. There were no other transfers from or into Level 3 during the periods presented.

Derivatives

Accounting Policy

The Company purchases swaps and forward contracts to manage foreign currency, interest rate and inflation exposure in its annuity reinsurance business. These derivative instruments are subject to a master netting arrangement, which creates a right of offset for amounts due to and due from a counterparty that is enforceable in the event of a default or bankruptcy. These derivatives are measured at fair value and reported on a gross basis in “other assets” or “other liabilities” on the condensed consolidated balance sheets, with changes in fair value reported in “fair value gains (losses) on derivatives” in the condensed consolidated statements of operations.

The Company also evaluates its reinsurance contract terms to identify embedded derivatives. If (i) the embedded derivative is not clearly and closely related to the economic characteristics of the host reinsurance contract, (ii) the reinsurance contract is not subject to recurring fair value measurement, and (iii) a separate instrument with the same terms would qualify as a derivative, then the embedded derivative is bifurcated and measured at fair value.

The Company identified an embedded derivative whereby the Company has a right to receive the total return on the assets supporting the funds withheld coinsurance arrangement related to the MYGA block of business. The fair value of this embedded derivative is included in “funds withheld” on the condensed consolidated balance sheets and the change in its fair value, which is based on the unrealized gains and losses of the underlying assets, is reported in “fair value gains (losses) on derivatives” in the condensed consolidated statements of operations.