SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business Aflac Incorporated (the Parent Company) and its subsidiaries (collectively, the Company) primarily sell supplemental health and life insurance in the United States (U.S.) and Japan. The Company's insurance business is marketed and administered through American Family Life Assurance Company of Columbus (Aflac) in the U.S. and through Aflac Life Insurance Japan Ltd. (ALIJ) in Japan. The Company’s operations consist of two reportable business segments: Aflac U.S., which includes Aflac, and Aflac Japan, which includes ALIJ. American Family Life Assurance Company of New York (Aflac New York) is a wholly owned subsidiary of Aflac. Most of Aflac's policies are individually underwritten and marketed through independent agents.With the exception of dental and vision products administered by Argus Dental & Vision, Inc. (Argus) and certain group life insurance products, Aflac U.S. markets and administers group products through Continental American Insurance Company (CAIC), branded as Aflac Group Insurance. The Company's insurance operations in the U.S. and Japan service the two markets for the Company's insurance business. Aflac Japan's revenues, including net gains and losses on its investment portfolio, accounted for 69% of the Company's total revenues in 2021, compared with 68% in 2020 and 69% in 2019. The percentage of the Company's total assets attributable to Aflac Japan was 82% at December 31, 2021, compared with 83% at December 31, 2020. In November 2020, the Company, through its insurance subsidiaries Aflac and Aflac New York, acquired Zurich North America’s U.S. Corporate Life and Pensions business (Zurich), which consists of group life, disability and absence management products. Aflac and Aflac New York will reinsure on an indemnity basis Zurich's in-force group life and disability policies. Aflac also acquired assets needed to support the group life and disability business, along with an absence management platform. In November 2019, the Company acquired Argus Holdings, LLC and its subsidiary Argus Dental & Vision, Inc. (Argus), a benefits management organization and national network dental and vision company, which provides a platform for Aflac Dental and Vision. Argus is an addition to the Aflac U.S. segment. Basis of Presentation The Company prepares its financial statements in accordance with U.S. generally accepted accounting principles (U.S. GAAP). These principles are established primarily by the Financial Accounting Standards Board (FASB). In these Notes to the Consolidated Financial Statements, references to U.S. GAAP issued by the FASB are derived from the FASB Accounting Standards CodificationTM (ASC). The preparation of financial statements in conformity with U.S. GAAP requires the Company to make estimates based on currently available information when recording transactions resulting from business operations. The most significant items on the Company's balance sheet that involve a greater degree of accounting estimates and actuarial determinations subject to changes in the future are the valuation of investments and derivatives, deferred policy acquisition costs (DAC), liabilities for future policy benefits and unpaid policy claims, and income taxes. These accounting estimates and actuarial determinations are sensitive to market conditions, investment yields, mortality, morbidity, commission and other acquisition expenses, and terminations by policyholders. As additional information becomes available, or actual amounts are determinable, the recorded estimates are revised and reflected in operating results. Although some variability is inherent in these estimates, the Company believes the amounts provided are reasonable and reflective of the best estimates of management. The consolidated financial statements include the accounts of the Parent Company, its subsidiaries, and those entities required to be consolidated under applicable accounting standards. All material intercompany accounts and transactions have been eliminated.
Coronavirus Disease 2019 (COVID-19)	Coronavirus Disease 2019 (COVID-19): The impact of the COVID-19 global pandemic on the Company continues to evolve. Both Aflac Japan and Aflac U.S. have taken measures to address employee health and safety and increase employees’ ability to develop and maintain more flexible working conditions, with return to office undertaken as warranted by local conditions, and operations have remained stable throughout 2021. The Company continues to monitor its investment portfolios to adjust to market conditions, including the continuing recovery, changes in monetary policy and inflation. Both Aflac Japan and Aflac U.S. have accelerated investments in digital initiatives to improve productivity, efficiency and customer service over the long term. The Company also continues to closely monitor the effects and risks of COVID-19 to assess its impact on economic conditions in Japan and the U.S. and on the Company's business, financial condition, results of operations, liquidity and capital position.
Foreign Currency Translation	Foreign Currency Translation: The functional currency of Aflac Japan is the Japanese yen. The Company translates its yen-denominated financial statement accounts into U.S. dollars as follows. Assets and liabilities are translated at end-of-period exchange rates. Realized gains and losses on security transactions are translated at the exchange rate on the trade date of each transaction. Other revenues, expenses, and cash flows are translated using average exchange rates for the period. The resulting currency translation adjustments are reported in accumulated other comprehensive income. The Company includes in earnings the realized currency exchange gains and losses resulting from foreign currency transactions. The Parent Company has designated a majority of its yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedges and from time-to-time may designate certain foreign currency forwards and options as derivative hedges of the foreign currency exposure of the Company's net investment in Aflac Japan. Outstanding principal and related accrued interest on these Parent Company liabilities and the fair value of these derivatives are translated into U.S. dollars at end-of-period exchange rates. Currency translation adjustments and changes in the fair value of these derivatives are recorded as unrealized foreign currency translation gains (losses) in other comprehensive income and are included in accumulated other comprehensive income.
Insurance Revenue and Expense Recognition	Insurance Revenue and Expense Recognition: Substantially all of the supplemental health and life insurance policies the Company issues are classified as long-duration contracts. The contract provisions generally cannot be changed or canceled during the contract period; however, the Company may adjust premiums for supplemental health policies issued in the U.S. within prescribed guidelines and with the approval of state insurance regulatory authorities. Insurance premiums for most of the Company's health and life policies, including cancer, accident, hospital, critical illness, dental, vision, term life, whole life, long-term care and disability, are recognized as earned premiums over the premium-paying periods of the contracts when due from policyholders. When earned premiums are reported, the related amounts of benefits and expenses are charged against such revenues, so that profits are recognized in proportion to earned premiums during the period the policies are expected to remain in force. This association is accomplished by means of annual additions to the liability for future policy benefits and the deferral and subsequent amortization of policy acquisition costs. Premiums from the Company's products with limited-pay features, including term life, whole life, WAYS, and child endowment, are collected over a significantly shorter period than the period over which benefits are provided. Premiums for these products are recognized as earned premiums over the premium-paying periods of the contracts when due from policyholders. Any gross premium in excess of the net premium is deferred and recorded in earnings, such that profits are recognized in a constant relationship with insurance in force. Benefits are recorded as an expense when they are incurred. A liability for future policy benefits is recorded when premiums are recognized using the net premium method. At the policyholder's option, customers can also pay discounted advanced premiums for certain of the Company's products. Advanced premiums are deferred and recognized when due from policyholders over the regularly scheduled premium payment period. The calculation of DAC and the liability for future policy benefits requires the use of estimates based on sound actuarial valuation techniques. For new policy issues, the Company reviews its actuarial assumptions and deferrable acquisition costs each year and revises them when necessary to more closely reflect recent experience and studies of actual acquisition costs. For policies in force, the Company evaluates DAC by major product groupings to determine that they are recoverable from future revenues, and any amounts determined not to be recoverable are charged against net earnings. The Company has not had any material charges to earnings for DAC that was determined not to be recoverable in any of the years presented in this Form 10-K.
Advertising Expense	Advertising expense is reported as incurred in insurance expenses in the consolidated statements of earnings.
Cash and Cash Equivalents	Cash and Cash Equivalents: Cash and cash equivalents include cash on hand, money market instruments, and other debt instruments with a maturity of 90 days or less when purchased.
Investments	Investments: The Company's debt securities consist of fixed maturity securities, which are classified as either held to maturity or available for sale. Securities classified as held to maturity are securities that the Company has the ability and intent to hold to maturity or redemption and are carried at amortized cost. All other fixed maturity debt securities are classified as available for sale and are carried at fair value. If the fair value is higher than the amortized cost for debt securities, the excess is an unrealized gain, and if lower than cost, the difference is an unrealized loss. The net unrealized gains and losses on securities available for sale, less related deferred income taxes, are recorded through other comprehensive income and included in accumulated other comprehensive income. Amortized cost of debt securities is based on the Company's purchase price adjusted for accrual of discount, or amortization of premium, and recognition of impairment charges, if any. The amortized cost of debt securities the Company purchases at a discount or premium will equal the face or par value at maturity or the call date, if applicable. Interest is reported as income when earned and is adjusted for amortization of any premium or discount. The Company has investments in marketable equity securities which are carried at fair value. Changes in the fair value of equity securities are recorded in earnings as a component of net investment gains and losses. The Company has investments in variable interest entities (VIEs). Criteria for evaluating VIEs for consolidation focuses on identifying which enterprise has the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and (1) the obligation to absorb losses of the entity or (2) the right to receive benefits from the entity. The Company is the primary beneficiary of certain VIEs, and therefore consolidates these entities in its financial statements. While the consolidated VIEs generally operate within a defined set of contractual terms, there are certain powers that are retained by the Company that are considered significant in the conclusion that the Company is the primary beneficiary. These powers vary by structure but generally include the initial selection of the underlying collateral; the ability to obtain the underlying collateral in the event of default; and, the ability to appoint or dismiss key parties in the structure. In particular, the Company's powers surrounding the underlying collateral were considered to be the most significant powers because these most significantly impact the economics of the VIE. The Company has no obligation to provide any continuing financial support to any of the entities in which it is the primary beneficiary. The Company's maximum loss is limited to its original investment. Neither the Company nor any of its creditors have the ability to obtain the underlying collateral, nor does the Company have control over the instruments held in the VIEs, unless there is an event of default. For those entities where the Company is the primary beneficiary, the consolidated entity's assets are segregated on the balance sheet by the caption "consolidated variable interest entities," and consist of fixed maturity securities, equity securities, loan receivables, limited partnerships and derivative instruments. For the mortgage- and asset-backed securities held in the Company's fixed maturity portfolio, the Company recognizes income using a constant effective yield, which is based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The net investment in mortgage- and asset-backed securities is adjusted to the amount that would have existed had the new effective yield been applied at the time of acquisition. This adjustment is reflected in net investment income. The Company uses the specific identification method to determine the gain or loss from securities transactions and report the realized gain or loss in the consolidated statements of earnings as net investment gain or loss. Securities transactions are accounted for based on values as of the trade date of the transaction. The Company lends fixed maturity and public equity securities to financial institutions in short-term security-lending transactions. These securities continue to be carried as investment assets on the Company's balance sheet during the terms of the loans and are not reported as sales. The Company receives cash or other securities as collateral for such loans. For loans involving unrestricted cash or securities as collateral, the collateral is reported as an asset with a corresponding liability for the return of the collateral. For loans where the Company receives as collateral securities that the Company is not permitted to sell or repledge, the collateral is not reported as an asset. Commercial mortgage and other loans include transitional real estate loans (TREs), commercial mortgage loans (CMLs) and middle market loans (MMLs). The Company's investments in TREs, CMLs, and MMLs are accounted for as loan receivables and are recorded at amortized cost on the acquisition date. The Company has the intent and ability to hold these loan receivables for the foreseeable future or until they mature and therefore, they are considered held for investment and are carried at amortized cost in the commercial mortgage and other loans line in its consolidated balance sheets. The amortized cost of the loan receivables reflects allowances for expected lifetime losses estimated as of each reporting date. Other investments include policy loans, limited partnerships, and short-term investments with maturities at the time of purchase of one year or less, but greater than 90 days. Limited partnerships are accounted for using the equity method of accounting. Under the equity method of accounting, the Company reports its proportionate share of the investee's earnings or losses as a component of net investment income in its consolidated statements of earnings. The underlying investments held by the Company’s limited partnerships primarily consist of private equity and real estate. Short-term investments are stated at amortized cost, which approximates fair value.
Credit Losses	Credit Losses: The Company estimates expected lifetime credit losses on financial assets measured at amortized cost including short-term receivables, premiums receivable, held-to-maturity fixed maturity securities, loan receivables, loan commitments and reinsurance recoverables. For available-for-sale fixed maturity securities, the Company evaluates estimated credit losses only when the fair value of the available-for-sale fixed maturity security is below its amortized cost basis. Credit loss changes are recorded as a component of net investment gains and losses for the Company’s held-to-maturity and available-for-sale securities, loan receivables, loan commitments and reinsurance recoverables, whereas credit losses on premium receivables are recorded in net earned premiums in the consolidated statement of earnings. The Company’s off-balance sheet credit exposure is primarily attributable to loan commitments that are not unconditionally cancellable. The Company considers the contractual period of exposure to credit risk, the likelihood that funding will occur, the risk of loss, and the current conditions and expectations of future economic conditions to develop the estimate of expected credit losses. The Company records the estimate of expected credit losses for certain loan commitments within other liabilities in the consolidated balance sheet. Write-offs and partial write-offs are recorded as a reduction to the amortized cost of the loan or fixed maturity security balance and a corresponding reduction to the credit allowance. The Company has elected not to measure an allowance on accrued interest income for all asset types, because the uncollectible accrued interest receivable is written off in a timely manner. The Company writes off accrued interest when it is more than ninety days past due by reducing interest income, which is a component of net investment income, in the consolidated statement of earnings. The Company records due premium receivable net of current expected credit losses in the receivables line item in the consolidated balance sheet, utilizing an aging methodology based on historical loss information, adjusted for current conditions and reasonable and supportable forecasts. Changes in the estimated credit losses related to premium receivable are recorded in net earned premiums in the consolidated statement of earnings. Prior to January 1, 2020, the Company followed other-than-temporary impairment (OTTI) guidance for its fixed maturity securities to recognize and measure OTTIs for its held-to-maturity and available-for-sale securities. For loans and loan receivables, the amortized cost reflected allowances for expected incurred losses based on past events and current economic conditions as of each reporting date.
Derivatives and Hedging	Derivatives and Hedging: Freestanding derivative instruments are reported in the consolidated balance sheet at fair value and are reported in other assets and other liabilities, with changes in value reported in earnings and/or other comprehensive income. These freestanding derivatives are foreign currency forwards, foreign currency options, foreign currency swaps, interest rate swaps and interest rate swaptions. The Company does not use derivatives for trading purposes, nor does the Company engage in leveraged derivative transactions. From time to time, the Company purchases certain investments that contain an embedded derivative. The Company assesses whether this embedded derivative is clearly and closely related to the asset that serves as its host contract. If the Company deems that the embedded derivative's terms are not clearly and closely related to the host contract, and a separate instrument with the same terms would qualify as a derivative instrument, the derivative is separated from that contract, held at fair value, and reported with the host instrument in the consolidated balance sheet, with changes in fair value reported in earnings. If the Company has elected the fair value option, the embedded derivative is not bifurcated, and the entire investment is held at fair value with changes in fair value reported in earnings. See Note 5 for a discussion on how the Company determines the fair value of its derivatives. Accruals on derivatives are typically recorded in other assets or within other liabilities in the consolidated balance sheets. To qualify for hedge accounting treatment, a derivative must be highly effective in mitigating the designated risk attributable to the hedged item. At the inception of hedging relationships the Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objectives and strategies for undertaking the respective hedging relationship, and the methodology that will be used to assess the effectiveness of the hedge relationship at and subsequent to hedge inception. The Company documents the designation of each hedge as either (i) a hedge of the variability of cash flows to be received or paid related to a recognized asset or liability or the hedge of a forecasted transaction ("cash flow hedge"); (ii) a hedge of the estimated fair value of a recognized asset or liability ("fair value hedge"); or (iii) a hedge of a net investment in a foreign operation ("net investment hedge"). The documentation process includes linking derivatives and non-derivative financial instruments that are designated as hedges to specific assets or groups of assets or liabilities in the statement of financial position or to specific forecasted transactions and defining the effectiveness testing methods to be used. At the hedge inception and on an ongoing quarterly basis, the Company also formally assesses whether the derivatives and non-derivative financial instruments used in hedging activities have been, and are expected to continue to be, highly effective in offsetting their designated risk. Hedge effectiveness is assessed using qualitative and quantitative methods. The assessment of hedge effectiveness determines the accounting treatment of changes in fair value. For assessing hedge effectiveness, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression, dollar offset, or other statistical analysis of changes in fair value or cash flows associated with the hedge relationship. For derivative instruments that are designated and qualify as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of accumulated other comprehensive income (loss) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. In cash flow hedges, all components of each derivative's gain or loss are included in the assessment of hedge effectiveness. The ineffective portion of the change in the fair value of the derivative is recognized in earnings when it occurs. For derivative instruments that are designated and qualify as fair value hedges, the gain or loss on the hedged item and the portion of the hedging instrument included in the assessment of effectiveness are recorded in the line item of the consolidated statements of earnings in which gain or loss on the hedged item is recorded. When assessing the effectiveness of the Company's fair value hedges, the Company excludes the changes in fair value related to the difference between the spot and the forward rate on its foreign currency forwards, the fair value not resulting from fluctuations in spot currency rates on the final notional exchange on cross currency swaps, and the time value of money of foreign exchange options and interest rate swaptions. For interest rate swaptions and cross-currency interest rate swaps designated under fair value hedges of interest rate risk, the change in the time value of money is recognized in other comprehensive income (loss) and amortized into earnings (net investment income) over its legal term. As discussed in Note 4, from time to time the Company designates net investment hedges of its net investment in Aflac Japan. The Company makes its net investment hedge designation at the beginning of each quarter. For derivative hedging instruments designated as net investment hedges, Aflac follows the spot-rate method. According to that method, the change in fair value of the hedging instrument due to fluctuations in the spot exchange rate is recorded in the unrealized foreign currency component of other comprehensive income and reclassified to earnings only when the hedged net investment is sold, or when a liquidation of the respective net investment in the foreign entity is substantially completed. If and when a sale or liquidation occurs, the changes in fair value of the derivative deferred in the unrealized foreign currency component of other comprehensive income will be released in the same income statement line item where the gain (loss) on the hedged net investment would be recorded upon sale. All other changes in fair value of the hedging instrument are considered the “excluded component” and are accounted for in net investment gains (losses). Should these designated net investment hedge positions exceed the Company's net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds its investment in Aflac Japan would be recognized in current earnings within net investment gains (losses). The Company discontinues hedge accounting prospectively when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the estimated cash flows or fair value of a hedged item; (2) the derivative is de-designated as a hedging instrument; or (3) the derivative expires or is sold, terminated or exercised. When hedge accounting is discontinued on a cash flow hedge or fair value hedge, the derivative is carried in the consolidated balance sheets at its estimated fair value, with changes in estimated fair value recognized in current period earnings. For discontinued cash flow hedges, including those where the derivative is sold, terminated or exercised, amounts previously deferred in other comprehensive income (loss) are reclassified into earnings when earnings are impacted by the cash flow of the hedged item. If a derivative is not designated as an accounting hedge or its use in managing risk does not qualify for hedge accounting, changes in the estimated fair value of the derivative are generally reported within other gains (losses), which is a component of net investment gains (losses). The fluctuations in estimated fair value of derivatives that have not been designated for hedge accounting can result in volatility in net earnings. The Company receives and pledges cash or other securities as collateral on open derivative positions. Cash received as collateral is reported as an asset with a corresponding liability for the return of the collateral. Cash pledged as collateral is recorded as a reduction to cash, and a corresponding receivable is recognized for the return of the cash collateral. The Company generally can repledge or resell collateral obtained from counterparties, although the Company does not typically exercise such rights. Securities received as collateral are not recognized unless the Company was to exercise its right to sell that collateral or exercise remedies on that collateral upon a counterparty default. Securities that the Company has pledged as collateral continue to be carried as investment assets on its balance sheet.
Deferred Policy Acquisition Costs	Deferred Policy Acquisition Costs: Certain direct and incremental costs of acquiring insurance contracts are deferred and amortized with interest over the premium payment periods in proportion to the ratio of annual earned premium to total anticipated earned premium. Anticipated earned premium is estimated by using the same mortality, persistency and interest assumptions used in computing liabilities for future policy benefits. In this manner, the related acquisition expenses are matched with revenues. Deferred costs include the excess of current-year commissions over ultimate renewal-year commissions and certain incremental direct policy issue, underwriting and sales expenses. All of these incremental costs are directly related to successful policy acquisition. For some products, policyholders can elect to modify product benefits, features, rights or coverages by exchanging a contract for a new contract or by amendment, endorsement, or rider to a contract, or by the election of a feature or coverage within a contract. These transactions are known as internal replacements. The Company performs a two-stage analysis of the internal replacements to determine if the modification is substantive to the base policy. The stages of evaluation are as follows: 1) determine if the modification is integrated with the base policy, and 2) if it is integrated, determine if the resulting contract is substantially changed. For internal replacement transactions where the resulting contract is substantially unchanged, the policy is accounted for as a continuation of the replaced contract. Unamortized deferred acquisition costs from the original policy continue to be amortized over the expected life of the new policy, and the costs of replacing the policy are accounted for as policy maintenance costs and expensed as incurred. Examples include conversions of same age bands, certain family coverage changes, pricing era changes (decrease), ordinary life becomes reduced paid-up and certain reinstatements. An internal replacement transaction that results in a policy that is substantially changed is accounted for as an extinguishment of the original policy and the issuance of a new policy. Unamortized deferred acquisition costs on the original policy are immediately expensed, and the costs of acquiring the new policy are capitalized and amortized in accordance with the Company's accounting policies for deferred acquisition costs. Riders can be considered internal replacements that are either integrated or non-integrated resulting in either substantially changed or substantially unchanged treatment. Riders are evaluated based on the specific facts and circumstances of the rider and are considered an expansion of the existing benefits with additional premium required. Non-integrated riders to existing contracts do not change the Company's profit expectations for the related products and are treated as a new policy establishment for incremental coverage. The Company measures the recoverability of DAC and the adequacy of its policy reserves annually by performing gross premium valuations on its business. (See the following discussion for further information regarding policy reserves.)
Goodwill	Goodwill: Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. The amount of goodwill recognized is also impacted by measurement differences resulting from certain assets and liabilities not recorded at fair value (e.g. income taxes, employee benefits). Goodwill is not amortized, but is tested for impairment at a level of a reporting unit at least annually, in the same reporting period each year. Goodwill is included in the line item “Other” assets in the consolidated balance sheets and was $268 million as of December 31, 2021, compared with $269 million at December 31, 2020. A significant majority of the goodwill balance is attributable to the following business combinations within the Aflac U.S. segment, which represents the reporting unit for goodwill impairment testing: (i) CAIC acquisition in 2009, (ii) Empoweredbenefits acquisition in 2015, (iii) Argus acquisition in 2019, and (iv) acquisition of Zurich's business in the fourth quarter of 2020.
Policy Liabilities - Future Policy Benefits	Policy Liabilities: Future policy benefits represent insurance claims that are expected to occur in the future and are computed following a net level premium method using estimated future investment yields, persistency and recognized morbidity and mortality tables modified to reflect the Company's experience, including a provision for adverse deviation. These assumptions are generally established and considered locked at policy inception. These assumptions may only be unlocked in certain circumstances based on the results of periodic DAC recoverability and premium deficiency testing.
Policy Liabilities - Unpaid Policy Claims	Unpaid policy claims are estimates computed primarily on an undiscounted basis using statistical analyses of historical claims experience adjusted for current trends and changed conditions. The ultimate liability may vary significantly from such estimates. The Company regularly adjusts these estimates as new claims experience emerges and reflects the changes in operating results in the year such adjustments are made.
Unearned Premiums	Unearned premiums consist primarily of discounted advance premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as earned premiums over the contractual premium payment period.
Other Policy Liabilities	Other policyholders’ funds liability consists primarily of the fixed annuity line of business in Aflac Japan which has fixed benefits and premiums.
Internal Replacements of Insurance Contracts	For internal replacements that are determined to be substantially changed, policy liabilities related to the original policy that was replaced are immediately released, and policy liabilities are established for the new insurance contract. Further, the policy reserves are evaluated based on the new policy features, and any change (up or down) necessary is recognized at the date of contract change/modification. Examples include conversions to higher age bands, certain family coverage changes, pricing era changes (increase), lapse & re-issue, certain reinstatements and certain other contract conversions. However, for internal replacements that are considered substantially unchanged, no changes to the reserves are recognized.
Reinsurance	Reinsurance: The Company enters into reinsurance agreements with other companies in the normal course of business. For each reinsurance agreement, the Company determines if the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums, benefits and DAC are reported net of insurance ceded.
Income Taxes	Income Taxes: Income tax provisions are generally based on pretax earnings reported for financial statement purposes, which differ from those amounts used in preparing the Company's income tax returns. Deferred income taxes are recognized for temporary differences between the financial reporting basis and income tax basis of assets and liabilities, based on enacted tax laws and statutory tax rates applicable to the periods in which the Company expects the temporary differences to reverse. The Company records deferred tax assets for tax positions taken based on its assessment of whether the tax position is more likely than not to be sustained upon examination by taxing authorities. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized.
Policyholder Protection Corporation and State Guaranty Association Assessments	Policyholder Protection Corporation and State Guaranty Association Assessments: In Japan, the government has required the insurance industry to contribute to a policyholder protection corporation. The Company recognizes a charge for its estimated share of the industry's obligation once it is determinable. The Company reviews the estimated liability for policyholder protection corporation contributions on an annual basis and reports any adjustments in Aflac Japan's expenses. In the U.S., each state has a guaranty association that supports insolvent insurers operating in those states. The Company's policy is to accrue assessments when the entity for which the insolvency relates has met its state of domicile's statutory definition of insolvency, the amount of the loss is reasonably estimable and the related premium upon which the assessment is based is written. See Note 15 of the Notes to the Consolidated Financial Statements for further discussion of the guaranty fund assessments charged to the Company.
Treasury Stock	Treasury Stock: Treasury stock is reflected as a reduction of shareholders' equity at cost. The Company uses the weighted-average purchase cost to determine the cost of treasury stock that is reissued. The Company includes any gains and losses in additional paid-in capital when treasury stock is reissued.
Share-Based Compensation	Share-Based Compensation: The Company measures compensation cost related to its share-based payment transactions at fair value on the grant date, and the Company recognizes those costs in the financial statements over the vesting period during which the employee provides service in exchange for the award. The Company has made an entity-wide accounting policy election to estimate the number of awards that are expected to vest and the corresponding forfeitures.
Earnings Per Share	Earnings Per Share: The Company computes basic earnings per share (EPS) by dividing net earnings by the weighted-average number of unrestricted shares outstanding for the period. Diluted EPS is computed by dividing net earnings by the weighted-average number of shares outstanding for the period plus the shares representing the dilutive effect of share-based awards.
Reclassifications	Reclassifications: Certain reclassifications have been made to prior-year amounts to conform to current-year reporting classifications. These reclassifications had no impact on net earnings or total shareholders' equity.
Recently Adopted Accounting Pronouncements	New Accounting Pronouncements Recently Adopted Accounting Pronouncements ASU 2020-04 Reference Rate Reform: Facilitation of the Effects of Reference Rate Reform on Financial Reporting, as clarified and amended by: ASU 2021-01 Reference Rate Reform: Relief Extended to Derivatives Impacted by Discounting Transition In March 2020, the FASB issued amendments that provide optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions affected by the reference rate reform if certain criteria are met. The amendments in this ASU only apply to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate (LIBOR) or another reference rate expected to be discontinued because of reference rate reform. An entity may elect to apply the amendments as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. The amendments generally expire on December 31 2022, i.e., they do not apply to contract modifications made after December 31, 2022, new hedging relationships entered into after December 31, 2022, and hedging relationships evaluated for periods after December 31, 2022. In January 2021, the FASB issued a standard to permit entities to apply optional expedients in ASC 848 to derivative instruments modified because of discounting transition. Discounting transition refers to the changing of interest rates used for margining, discounting, or contract price alignment of derivative instruments to transition to alternative rates.The amendment is effective immediately. This standard was adopted on April 1, 2020. The adoption of the new guidance did not have an impact on the Company’s financial statements. The Company will continue to evaluate the impacts of reference rate reform on contract modifications and hedging relationships through December 31, 2022. ASU 2019-04 Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments In April 2019, the FASB issued Codification improvements to clarify and correct certain areas of guidance amended as part of ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities; ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments; and ASU 2017-12, Derivative and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. The most significant of these improvements to the Company was related to the Codification improvement to ASU 2017-12 and the clarification that a one-time reclassification of assets that are eligible to be hedged under the last-of-layer method (i.e., certain pre-payable securities) from held-to-maturity to available-for-sale is allowed under the new hedge accounting guidance and would not impact the Company’s ability to continue to classify other bonds as held-to-maturity. The other amendments related to ASU 2017-12 and 2016-01 are either not significant, or were previously implemented as part of the related ASU adoptions. Applicable amendments related to ASU 2016-13 are discussed within the recent adoption of that update below. This standard was adopted on January 1, 2020. The adoption of this guidance resulted in a reclassification of $6.9 billion (at amortized cost) of pre-payable fixed-maturity securities from the held-to-maturity to the available-for-sale category. The reclassification resulted in recording in beginning 2020 accumulated other comprehensive income a net unrealized gain of $848 million on an after-tax basis, based on the securities’ fair values on the reclassification date. The reclassification impacted the adoption of ASU 2016-13 (see ASU 2016-13 below for additional details). ASU 2016-02 Leases, as clarified and amended by: ASU 2018-01, Leases: Land Easement Practical Expedient for Transition to Topic 842 ASU 2018-10, Codification Improvements to Topic 842, Leases ASU 2018-11, Leases, Targeted Improvements ASU 2018-20, Leases: Narrow-Scope Improvements for Lessors In February 2016, the FASB issued updated guidance for accounting for leases (“Leases Update”). Per the Leases Update, lessees are required to recognize all leases on the balance sheet with the exception of short-term leases. A lease liability will be recorded for the obligation of a lessee to make lease payments arising from a lease. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The Leases Update provided a number of optional practical expedients. The Company elected the "package of practical expedients," which permits the Company not to reassess under the new standard its prior conclusions about lease identification, lease classification and initial direct costs. Under the Leases Update, lessor accounting is unchanged. This standard was adopted on January 1, 2019. The Company has operating and finance leases for office space and equipment. The Company elected the short-term lease exemption for all classes of leases which allows the Company to not recognize right-of-use assets and lease liabilities on the consolidated balance sheet and allows the Company to recognize the lease expense for short-term leases on a straight-line basis over the lease term. The Company elected the practical expedient to not separate lease and non-lease components and applied it to all classes of leases where the non-lease components are not significant. Some of the Company's leases include options to extend or terminate the lease and the lease terms may include such options when it is reasonably certain that the Company will exercise that option. Certain leases also include options to purchase the leased property. The leases within scope of the leases update increased the Company's right-of-use assets and lease liabilities recorded in its beginning 2019 consolidated balance sheet by $134 million. As of January 1, 2019, the Company did not have land easements, but has elected the practical expedient as a safe harbor. The Company elected the optional transition method and as a safe harbor, the practical expedient provided to lessors. The Company has made an accounting policy election to exclude amounts collected from customers for all sales (and other similar) taxes from the transaction price. The adoption of the Leases Update and related amendments did not have a significant impact on the Company's financial position, results of operations, or disclosures. ASU 2016-13 Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments, as clarified and amended by: ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ASU 2019-05, Financial Instruments - Credit Losses (Topic 326), Targeted Transition Relief ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments - Credit Losses In June 2016, the FASB issued amendments that require a financial asset (or a group of financial assets) measured at amortized cost to be presented net of an allowance for credit losses (Credit Losses ASU) in order to reflect the amount expected to be collected on the financial asset(s). The measurement of expected credit losses is amended by replacing the incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information. Credit losses on available-for-sale debt securities is measured in a manner similar to prior U.S. GAAP; however, the amendments require that credit losses be presented as an allowance rather than as a write-down. Other amendments include changes to the balance sheet presentation and interest income recognition of purchased financial assets with a more-than-insignificant credit deterioration since origination (PCD financial assets). This standard was adopted on January 1, 2020. The Company recorded a cumulative effect adjustment with a decrease to beginning 2020 retained earnings of $56 million, net of taxes. See Note 3 of the Notes to the Consolidated Financial Statements for credit loss disclosures. The following line items in the consolidated balance sheets were most significantly impacted by the adoption of the new accounting standard: •Fixed maturity securities held to maturity, at amortized cost •Commercial mortgage and other loans •Reinsurance recoverable, included within Other asset
Description of Accounting Pronouncements Pending Adoption	Accounting Pronouncements Pending Adoption ASU 2018-12 Financial Services - Insurance: Targeted Improvements to the Accounting for Long-Duration Contracts, as clarified and amended by: ASU 2019-09 Financial Services - Insurance: Effective Date ASU 2020-11 Financial Services - Insurance: Effective Date and Early Application In August 2018, the FASB issued amendments that will significantly change how insurers account for long-duration contracts. The amendments will change existing recognition, measurement, presentation, and disclosure requirements. Issues addressed in the new guidance include: 1) a requirement to review and, if there is a change, update assumptions for the liability for future policy benefits at least annually, and to update the discount rate assumption quarterly, 2) accounting for market risk benefits at fair value, 3) simplified amortization for deferred acquisition costs, and 4) enhanced financial statement presentation and disclosures. In November 2019, the FASB issued an amendment extending the effective date for public business entities that meet the definition of an SEC filer, excluding entities eligible to be small reporting companies as defined by the SEC, by one year. In November 2020, the FASB issued an amendment providing an additional year deferral for all insurance entities due to the impact of COVID-19. The amendments are now effective for the Company for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2022. Early application of the amendments is permitted. The Company continues to evaluate the impact of adoption and expects that the adoption will have a significant impact on the Company’s financial position, results of operations, and disclosures. The Company anticipates that the requirement to update assumptions for liability for future policy benefits (LFPB) will have a significant impact on its results of operations, systems, processes and controls and that the requirement to update discount rates will have a significant impact on its equity. As part of working toward implementation of the updated standard, the Company has made progress on key accounting policy decisions, including processes to identify insurance policy groupings (cohorts) for LFPB measurement and DAC amortization purposes, applicable discount rates, development of liability cash flow and claim expense assumptions, and DAC amortization methodology. The Company will not early adopt the updated standard and has selected the modified retrospective transition method. Based upon this transition method, the Company currently estimates that the January 1, 2021 transition date (Transition Date) impact from adoption is likely to result in a decrease in accumulated other comprehensive income (AOCI) in a range between $18 billion and $20 billion. This is due to updating the LFPB discount rate assumptions from the rates locked in for reserves held as of the Transition Date to rates determined by reference to the Transition Date market level yields for upper-medium-grade (low credit risk) fixed income instruments (as of December 31, 2020). The variability around the impact of adoption results from the Company making certain estimates, primarily related to the determination of Transition Date market level yields. The Company has advanced and continues to refine the design of its discount rate methodology for both the U.S. and Japan insurance business. The methodology incorporates constructing a discount rate curve separately for discounting cash flows used to calculate the U.S. and Japan LFPB, with each curve intended to be reflective of the currency, tenor and characteristics of the insurance liabilities. Discount rates comprising each curve will be determined by reference to upper-medium grade (low credit risk) fixed-income instrument yields that are intended to reflect the duration characteristics of the corresponding insurance liabilities. The Company intends to use for these yields single-A rated fixed income instruments with credit ratings based on international rating standards. Where only local ratings are available, the Company intends to select the fixed-income instruments with local ratings that are equivalent to a single-A rating based on international rating standards. The methodology will be designed to prioritize observable inputs based on market data available in the local debt markets where the respective policies were issued in the currency in which the policies are denominated. For the discount rates applicable to tenors for which the single-A debt market is not liquid or there is little or no observable market data, the Company will use various estimation techniques consistent with the fair value guidance in ASC 820, which include, but are not limited to: (i) for tenors where there is less observable market data and/or the observable market data is available for similar instruments, estimating tenor-specific single-A credit spreads and applying them to risk-free government rates; (ii) for tenors where there is very limited or no observable single-A or similar market data, interpolation and extrapolation techniques. Discount rates will be updated each reporting period. Long duration insurance contracts issued by the Company will be grouped into annual calendar-year cohorts based on the contract issue date, reportable segment, legal entity and product type. Limited pay contracts will be grouped into separate cohorts from other traditional products in the same manner and will be further separated based on their premium payment structures. Riders will be combined with base policies with similar insurance coverage types and the same contract issue years. In addition to the preliminary policy elections related to cohorts and LFPB discount rates directly impacting Transition Date AOCI, the Company has also advanced the following accounting policies relevant to the post-Transition Date accounting: •Cash flow assumptions underlying insurance liabilities will be evaluated as to whether an update is needed at least annually in the same fiscal quarter each year. To facilitate the review, experience studies will be performed annually in the consistent quarter year-to-year to substantiate assumptions, including mortality, morbidity, and terminations in future periods. •Locked-in discount rates used for the computation of interest accretion on LFPB for policies issued on or after January 1, 2021 will be determined for each issue-year cohort as a single discount rate, calculated as the weighted-average of monthly upper-medium grade (low-credit risk) fixed-income instrument forward curves over the calendar year, determined using the methodology described above and weighted using issued annualized premiums for each issue month. The single discount rate for each issue-year cohort will remain unchanged after the calendar year of issue. Locked-in discount rates on the policies held at Transition Date reflect the locked-in rates in existence immediately before the Transition Date. •For DAC amortization, the Company has made a preliminary election to group insurance policies into cohorts that are consistent with the groupings used in estimating the associated LFPB. DAC will be amortized on a constant level basis for the grouped contracts over the expected remaining term of the related contracts. For both life and health products issued by Aflac Japan, the constant-level basis used will be units in force, which is a proxy for face amount and insurance in force, respectively. For life products issued by Aflac U.S., the constant level basis used will be face amount of policies in force; for health products issued by Aflac U.S., the constant level basis used will be the number of policies in force. •The Company has made a preliminary entity-wide election to use locked-in claim expense assumptions determined for each issue-year cohort as a percentage of incurred claims; these assumptions would remain unchanged over the term of the insurance policy. The Company has created a governance framework and a plan to support implementation of the updated standard. As part of its implementation plan, the Company has also advanced the modernization of its actuarial technology platform to enhance its modeling, data management, experience study and analytical capabilities, increase the end-to-end automation of key reporting and analytical processes and optimize its control framework. The Company has also put in place internal controls related to the new processes created as part of implementing the updated standard and will continue to refine and maturate these internal controls until the formal implementation in the first quarter of 2023. The Company has recently begun testing its reporting and disclosure capabilities under the new ASU for post-Transition Date accounting periods. The Company currently has no products with market risk benefits.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Description of Business and Basis of Presentation

Description of Business

Aflac Incorporated (the Parent Company) and its subsidiaries (collectively, the Company) primarily sell supplemental health and life insurance in the United States (U.S.) and Japan. The Company's insurance business is marketed and administered through American Family Life Assurance Company of Columbus (Aflac) in the U.S. and through Aflac Life Insurance Japan Ltd. (ALIJ) in Japan. The Company’s operations consist of two reportable business segments: Aflac U.S., which includes Aflac, and Aflac Japan, which includes ALIJ. American Family Life Assurance Company of New York (Aflac New York) is a wholly owned subsidiary of Aflac. Most of Aflac's policies are individually underwritten and marketed through independent agents.With the exception of dental and vision products administered by Argus Dental & Vision, Inc. (Argus) and certain group life insurance products, Aflac U.S. markets and administers group products through Continental American Insurance Company (CAIC), branded as Aflac Group Insurance. The Company's insurance operations in the U.S. and Japan service the two markets for the Company's insurance business. Aflac Japan's revenues, including net gains and losses on its investment portfolio, accounted for 69% of the Company's total revenues in 2021, compared with 68% in 2020 and 69% in 2019. The percentage of the Company's total assets attributable to Aflac Japan was 82% at December 31, 2021, compared with 83% at December 31, 2020.

In November 2020, the Company, through its insurance subsidiaries Aflac and Aflac New York, acquired Zurich North America’s U.S. Corporate Life and Pensions business (Zurich), which consists of group life, disability and absence management products. Aflac and Aflac New York will reinsure on an indemnity basis Zurich's in-force group life and disability policies. Aflac also acquired assets needed to support the group life and disability business, along with an absence management platform.

In November 2019, the Company acquired Argus Holdings, LLC and its subsidiary Argus Dental & Vision, Inc. (Argus), a benefits management organization and national network dental and vision company, which provides a platform for Aflac Dental and Vision. Argus is an addition to the Aflac U.S. segment.

Basis of Presentation

The Company prepares its financial statements in accordance with U.S. generally accepted accounting principles (U.S. GAAP). These principles are established primarily by the Financial Accounting Standards Board (FASB). In these Notes to the Consolidated Financial Statements, references to U.S. GAAP issued by the FASB are derived from the FASB Accounting Standards CodificationTM (ASC). The preparation of financial statements in conformity with U.S. GAAP requires the Company to make estimates based on currently available information when recording transactions resulting from business operations. The most significant items on the Company's balance sheet that involve a greater degree of accounting estimates and actuarial determinations subject to changes in the future are the valuation of investments and derivatives, deferred policy acquisition costs (DAC), liabilities for future policy benefits and unpaid policy claims, and income taxes. These accounting estimates and actuarial determinations are sensitive to market conditions, investment yields, mortality, morbidity, commission and other acquisition expenses, and terminations by policyholders. As additional information becomes available, or actual amounts are determinable, the recorded estimates are revised and reflected in operating results. Although some variability is inherent in these estimates, the Company believes the amounts provided are reasonable and reflective of the best estimates of management.

The consolidated financial statements include the accounts of the Parent Company, its subsidiaries, and those entities required to be consolidated under applicable accounting standards. All material intercompany accounts and transactions have been eliminated.

Coronavirus Disease 2019 (COVID-19)

Coronavirus Disease 2019 (COVID-19): The impact of the COVID-19 global pandemic on the Company continues to evolve. Both Aflac Japan and Aflac U.S. have taken measures to address employee health and safety and increase employees’ ability to develop and maintain more flexible working conditions, with return to office undertaken as warranted by local conditions, and operations have remained stable throughout 2021. The Company continues to monitor its investment portfolios to adjust to market conditions, including the continuing recovery, changes in monetary policy and inflation. Both Aflac Japan and Aflac U.S. have accelerated investments in digital initiatives to improve productivity, efficiency and customer service over the long term. The Company also continues to closely monitor the effects and risks of COVID-19 to assess its impact on economic conditions in Japan and the U.S. and on the Company's business, financial condition, results of operations, liquidity and capital position.

Foreign Currency Translation

Foreign Currency Translation: The functional currency of Aflac Japan is the Japanese yen. The Company translates its yen-denominated financial statement accounts into U.S. dollars as follows. Assets and liabilities are translated at end-of-period exchange rates. Realized gains and losses on security transactions are translated at the exchange rate on the trade date of each transaction. Other revenues, expenses, and cash flows are translated using average exchange rates for the period. The resulting currency translation adjustments are reported in accumulated other comprehensive income. The Company includes in earnings the realized currency exchange gains and losses resulting from foreign currency transactions.

The Parent Company has designated a majority of its yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedges and from time-to-time may designate certain foreign currency forwards and options as derivative hedges of the foreign currency exposure of the Company's net investment in Aflac Japan. Outstanding principal and related accrued interest on these Parent Company liabilities and the fair value of these derivatives are translated into U.S. dollars at end-of-period exchange rates. Currency translation adjustments and changes in the fair value of these derivatives are recorded as unrealized foreign currency translation gains (losses) in other comprehensive income and are included in accumulated other comprehensive income.

Insurance Revenue and Expense Recognition

Insurance Revenue and Expense Recognition: Substantially all of the supplemental health and life insurance policies the Company issues are classified as long-duration contracts. The contract provisions generally cannot be changed or canceled during the contract period; however, the Company may adjust premiums for supplemental health policies issued in the U.S. within prescribed guidelines and with the approval of state insurance regulatory authorities.

Insurance premiums for most of the Company's health and life policies, including cancer, accident, hospital, critical illness, dental, vision, term life, whole life, long-term care and disability, are recognized as earned premiums over the premium-paying periods of the contracts when due from policyholders. When earned premiums are reported, the related amounts of benefits and expenses are charged against such revenues, so that profits are recognized in proportion to earned premiums during the period the policies are expected to remain in force. This association is accomplished by means of annual additions to the liability for future policy benefits and the deferral and subsequent amortization of policy acquisition costs.

Premiums from the Company's products with limited-pay features, including term life, whole life, WAYS, and child endowment, are collected over a significantly shorter period than the period over which benefits are provided. Premiums for these products are recognized as earned premiums over the premium-paying periods of the contracts when due from policyholders. Any gross premium in excess of the net premium is deferred and recorded in earnings, such that profits are recognized in a constant relationship with insurance in force. Benefits are recorded as an expense when they are incurred. A liability for future policy benefits is recorded when premiums are recognized using the net premium method.

At the policyholder's option, customers can also pay discounted advanced premiums for certain of the Company's products. Advanced premiums are deferred and recognized when due from policyholders over the regularly scheduled premium payment period.

The calculation of DAC and the liability for future policy benefits requires the use of estimates based on sound actuarial valuation techniques. For new policy issues, the Company reviews its actuarial assumptions and deferrable acquisition costs each year and revises them when necessary to more closely reflect recent experience and studies of actual acquisition costs. For policies in force, the Company evaluates DAC by major product groupings to determine that they are recoverable from future revenues, and any amounts determined not to be recoverable are charged against net earnings. The Company has not had any material charges to earnings for DAC that was determined not to be recoverable in any of the years presented in this Form 10-K.

Advertising Expense

Advertising expense is reported as incurred in insurance expenses in the consolidated statements of earnings.

Cash and Cash Equivalents

Cash and Cash Equivalents: Cash and cash equivalents include cash on hand, money market instruments, and other debt instruments with a maturity of 90 days or less when purchased.

Investments

Investments: The Company's debt securities consist of fixed maturity securities, which are classified as either held to maturity or available for sale. Securities classified as held to maturity are securities that the Company has the ability and intent to hold to maturity or redemption and are carried at amortized cost.

All other fixed maturity debt securities are classified as available for sale and are carried at fair value. If the fair value is higher than the amortized cost for debt securities, the excess is an unrealized gain, and if lower than cost, the difference is an unrealized loss. The net unrealized gains and losses on securities available for sale, less related deferred income taxes, are recorded through other comprehensive income and included in accumulated other comprehensive income.

Amortized cost of debt securities is based on the Company's purchase price adjusted for accrual of discount, or amortization of premium, and recognition of impairment charges, if any. The amortized cost of debt securities the Company purchases at a discount or premium will equal the face or par value at maturity or the call date, if applicable. Interest is reported as income when earned and is adjusted for amortization of any premium or discount.

The Company has investments in marketable equity securities which are carried at fair value. Changes in the fair value of equity securities are recorded in earnings as a component of net investment gains and losses.

The Company has investments in variable interest entities (VIEs). Criteria for evaluating VIEs for consolidation focuses on identifying which enterprise has the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and (1) the obligation to absorb losses of the entity or (2) the right to receive benefits from the entity. The Company is the primary beneficiary of certain VIEs, and therefore consolidates these entities in its financial statements. While the consolidated VIEs generally operate within a defined set of contractual terms, there are certain powers that are retained by the Company that are considered significant in the conclusion that the Company is the primary beneficiary. These powers vary by structure but generally include the initial selection of the underlying collateral; the ability to obtain the underlying collateral in the event of default; and, the ability to appoint or dismiss key parties in the structure. In particular, the Company's powers surrounding the underlying collateral were considered to be the most significant powers because these most significantly impact the economics of the VIE. The Company has no obligation to provide any continuing financial support to any of the entities in which it is the primary beneficiary. The Company's maximum loss is limited to its original investment. Neither the Company nor any of its creditors have the ability to obtain the underlying collateral, nor does the Company have control over the instruments held in the VIEs, unless there is an event of default. For those entities where the Company is the primary beneficiary, the consolidated entity's assets are segregated on the balance sheet by the caption "consolidated variable interest entities," and consist of fixed maturity securities, equity securities, loan receivables, limited partnerships and derivative instruments.

For the mortgage- and asset-backed securities held in the Company's fixed maturity portfolio, the Company recognizes income using a constant effective yield, which is based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The net investment in mortgage- and asset-backed securities is adjusted to the amount that would have existed had the new effective yield been applied at the time of acquisition. This adjustment is reflected in net investment income.

The Company uses the specific identification method to determine the gain or loss from securities transactions and report the realized gain or loss in the consolidated statements of earnings as net investment gain or loss. Securities transactions are accounted for based on values as of the trade date of the transaction.

The Company lends fixed maturity and public equity securities to financial institutions in short-term security-lending transactions. These securities continue to be carried as investment assets on the Company's balance sheet during the terms of the loans and are not reported as sales. The Company receives cash or other securities as collateral for such loans. For loans involving unrestricted cash or securities as collateral, the collateral is reported as an asset with a corresponding liability for the return of the collateral. For loans where the Company receives as collateral securities that the Company is not permitted to sell or repledge, the collateral is not reported as an asset.

Commercial mortgage and other loans include transitional real estate loans (TREs), commercial mortgage loans (CMLs) and middle market loans (MMLs). The Company's investments in TREs, CMLs, and MMLs are accounted for as loan receivables and are recorded at amortized cost on the acquisition date. The Company has the intent and ability to hold these loan receivables for the foreseeable future or until they mature and therefore, they are considered held for investment and are carried at amortized cost in the commercial mortgage and other loans line in its consolidated balance sheets. The amortized cost of the loan receivables reflects allowances for expected lifetime losses estimated as of each reporting date.

Other investments include policy loans, limited partnerships, and short-term investments with maturities at the time of purchase of one year or less, but greater than 90 days. Limited partnerships are accounted for using the equity method of accounting. Under the equity method of accounting, the Company reports its proportionate share of the investee's earnings or losses as a component of net investment income in its consolidated statements of earnings. The underlying investments held by the Company’s limited partnerships primarily consist of private equity and real estate. Short-term investments are stated at amortized cost, which approximates fair value.

Credit Losses

Credit Losses: The Company estimates expected lifetime credit losses on financial assets measured at amortized cost including short-term receivables, premiums receivable, held-to-maturity fixed maturity securities, loan receivables, loan commitments and reinsurance recoverables. For available-for-sale fixed maturity securities, the Company evaluates estimated credit losses only when the fair value of the available-for-sale fixed maturity security is below its amortized cost basis. Credit loss changes are recorded as a component of net investment gains and losses for the Company’s held-to-maturity and available-for-sale securities, loan receivables, loan commitments and reinsurance recoverables, whereas credit losses on premium receivables are recorded in net earned premiums in the consolidated statement of earnings. The Company’s off-balance sheet credit exposure is primarily attributable to loan commitments that are not unconditionally cancellable. The Company considers the contractual period of exposure to credit risk, the likelihood that funding will occur, the risk of loss, and the current conditions and expectations of future economic conditions to develop the estimate of expected credit losses. The Company records the estimate of expected credit losses for certain loan commitments within other liabilities in the consolidated balance sheet.

Write-offs and partial write-offs are recorded as a reduction to the amortized cost of the loan or fixed maturity security balance and a corresponding reduction to the credit allowance.

The Company has elected not to measure an allowance on accrued interest income for all asset types, because the uncollectible accrued interest receivable is written off in a timely manner. The Company writes off accrued interest when it is more than ninety days past due by reducing interest income, which is a component of net investment income, in the consolidated statement of earnings.

The Company records due premium receivable net of current expected credit losses in the receivables line item in the consolidated balance sheet, utilizing an aging methodology based on historical loss information, adjusted for current conditions and reasonable and supportable forecasts. Changes in the estimated credit losses related to premium receivable are recorded in net earned premiums in the consolidated statement of earnings.

Prior to January 1, 2020, the Company followed other-than-temporary impairment (OTTI) guidance for its fixed maturity securities to recognize and measure OTTIs for its held-to-maturity and available-for-sale securities. For loans and loan receivables, the amortized cost reflected allowances for expected incurred losses based on past events and current economic conditions as of each reporting date.

Derivatives and Hedging

Derivatives and Hedging: Freestanding derivative instruments are reported in the consolidated balance sheet at fair value and are reported in other assets and other liabilities, with changes in value reported in earnings and/or other comprehensive income. These freestanding derivatives are foreign currency forwards, foreign currency options, foreign currency swaps, interest rate swaps and interest rate swaptions. The Company does not use derivatives for trading purposes, nor does the Company engage in leveraged derivative transactions.

From time to time, the Company purchases certain investments that contain an embedded derivative. The Company assesses whether this embedded derivative is clearly and closely related to the asset that serves as its host contract. If the Company deems that the embedded derivative's terms are not clearly and closely related to the host contract, and a separate instrument with the same terms would qualify as a derivative instrument, the derivative is separated from that contract, held at fair value, and reported with the host instrument in the consolidated balance sheet, with changes in fair value reported in earnings. If the Company has elected the fair value option, the embedded derivative is not bifurcated, and the entire investment is held at fair value with changes in fair value reported in earnings.

See Note 5 for a discussion on how the Company determines the fair value of its derivatives. Accruals on derivatives are typically recorded in other assets or within other liabilities in the consolidated balance sheets.

To qualify for hedge accounting treatment, a derivative must be highly effective in mitigating the designated risk attributable to the hedged item. At the inception of hedging relationships the Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objectives and strategies for undertaking the respective hedging relationship, and the methodology that will be used to assess the effectiveness of the hedge relationship at and subsequent to hedge inception. The Company documents the designation of each hedge as

either (i) a hedge of the variability of cash flows to be received or paid related to a recognized asset or liability or the hedge of a forecasted transaction ("cash flow hedge"); (ii) a hedge of the estimated fair value of a recognized asset or liability ("fair value hedge"); or (iii) a hedge of a net investment in a foreign operation ("net investment hedge"). The documentation process includes linking derivatives and non-derivative financial instruments that are designated as hedges to specific assets or groups of assets or liabilities in the statement of financial position or to specific forecasted transactions and defining the effectiveness testing methods to be used. At the hedge inception and on an ongoing quarterly basis, the Company also formally assesses whether the derivatives and non-derivative financial instruments used in hedging activities have been, and are expected to continue to be, highly effective in offsetting their designated risk. Hedge effectiveness is assessed using qualitative and quantitative methods. The assessment of hedge effectiveness determines the accounting treatment of changes in fair value.

For assessing hedge effectiveness, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression, dollar offset, or other statistical analysis of changes in fair value or cash flows associated with the hedge relationship.

For derivative instruments that are designated and qualify as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of accumulated other comprehensive income (loss) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. In cash flow hedges, all components of each derivative's gain or loss are included in the assessment of hedge effectiveness. The ineffective portion of the change in the fair value of the derivative is recognized in earnings when it occurs.

For derivative instruments that are designated and qualify as fair value hedges, the gain or loss on the hedged item and the portion of the hedging instrument included in the assessment of effectiveness are recorded in the line item of the consolidated statements of earnings in which gain or loss on the hedged item is recorded. When assessing the effectiveness of the Company's fair value hedges, the Company excludes the changes in fair value related to the difference between the spot and the forward rate on its foreign currency forwards, the fair value not resulting from fluctuations in spot currency rates on the final notional exchange on cross currency swaps, and the time value of money of foreign exchange options and interest rate swaptions. For interest rate swaptions and cross-currency interest rate swaps designated under fair value hedges of interest rate risk, the change in the time value of money is recognized in other comprehensive income (loss) and amortized into earnings (net investment income) over its legal term.

As discussed in Note 4, from time to time the Company designates net investment hedges of its net investment in Aflac Japan. The Company makes its net investment hedge designation at the beginning of each quarter. For derivative hedging instruments designated as net investment hedges, Aflac follows the spot-rate method. According to that method, the change in fair value of the hedging instrument due to fluctuations in the spot exchange rate is recorded in the unrealized foreign currency component of other comprehensive income and reclassified to earnings only when the hedged net investment is sold, or when a liquidation of the respective net investment in the foreign entity is substantially completed. If and when a sale or liquidation occurs, the changes in fair value of the derivative deferred in the unrealized foreign currency component of other comprehensive income will be released in the same income statement line item where the gain (loss) on the hedged net investment would be recorded upon sale. All other changes in fair value of the hedging instrument are considered the “excluded component” and are accounted for in net investment gains (losses). Should these designated net investment hedge positions exceed the Company's net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds its investment in Aflac Japan would be recognized in current earnings within net investment gains (losses).

The Company discontinues hedge accounting prospectively when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the estimated cash flows or fair value of a hedged item; (2) the derivative is de-designated as a hedging instrument; or (3) the derivative expires or is sold, terminated or exercised.

When hedge accounting is discontinued on a cash flow hedge or fair value hedge, the derivative is carried in the consolidated balance sheets at its estimated fair value, with changes in estimated fair value recognized in current period earnings. For discontinued cash flow hedges, including those where the derivative is sold, terminated or exercised, amounts previously deferred in other comprehensive income (loss) are reclassified into earnings when earnings are impacted by the cash flow of the hedged item.

If a derivative is not designated as an accounting hedge or its use in managing risk does not qualify for hedge accounting, changes in the estimated fair value of the derivative are generally reported within other gains (losses), which is a component of net investment gains (losses). The fluctuations in estimated fair value of derivatives that have not been designated for hedge accounting can result in volatility in net earnings.

The Company receives and pledges cash or other securities as collateral on open derivative positions. Cash received as collateral is reported as an asset with a corresponding liability for the return of the collateral. Cash pledged as collateral is recorded as a reduction to cash, and a corresponding receivable is recognized for the return of the cash collateral. The Company generally can repledge or resell collateral obtained from counterparties, although the Company does not typically exercise such rights. Securities received as collateral are not recognized unless the Company was to exercise its right to sell that collateral or exercise remedies on that collateral upon a counterparty default. Securities that the Company has pledged as collateral continue to be carried as investment assets on its balance sheet.

Deferred Policy Acquisition Costs

Deferred Policy Acquisition Costs: Certain direct and incremental costs of acquiring insurance contracts are deferred and amortized with interest over the premium payment periods in proportion to the ratio of annual earned premium to total anticipated earned premium. Anticipated earned premium is estimated by using the same mortality, persistency and interest assumptions used in computing liabilities for future policy benefits. In this manner, the related acquisition expenses are matched with revenues. Deferred costs include the excess of current-year commissions over ultimate renewal-year commissions and certain incremental direct policy issue, underwriting and sales expenses. All of these incremental costs are directly related to successful policy acquisition.

For some products, policyholders can elect to modify product benefits, features, rights or coverages by exchanging a contract for a new contract or by amendment, endorsement, or rider to a contract, or by the election of a feature or coverage within a contract. These transactions are known as internal replacements. The Company performs a two-stage analysis of the internal replacements to determine if the modification is substantive to the base policy. The stages of evaluation are as follows: 1) determine if the modification is integrated with the base policy, and 2) if it is integrated, determine if the resulting contract is substantially changed.

For internal replacement transactions where the resulting contract is substantially unchanged, the policy is accounted for as a continuation of the replaced contract. Unamortized deferred acquisition costs from the original policy continue to be amortized over the expected life of the new policy, and the costs of replacing the policy are accounted for as policy maintenance costs and expensed as incurred. Examples include conversions of same age bands, certain family coverage changes, pricing era changes (decrease), ordinary life becomes reduced paid-up and certain reinstatements.

An internal replacement transaction that results in a policy that is substantially changed is accounted for as an extinguishment of the original policy and the issuance of a new policy. Unamortized deferred acquisition costs on the original policy are immediately expensed, and the costs of acquiring the new policy are capitalized and amortized in accordance with the Company's accounting policies for deferred acquisition costs.

Riders can be considered internal replacements that are either integrated or non-integrated resulting in either substantially changed or substantially unchanged treatment. Riders are evaluated based on the specific facts and circumstances of the rider and are considered an expansion of the existing benefits with additional premium required. Non-integrated riders to existing contracts do not change the Company's profit expectations for the related products and are treated as a new policy establishment for incremental coverage.

The Company measures the recoverability of DAC and the adequacy of its policy reserves annually by performing gross premium valuations on its business. (See the following discussion for further information regarding policy reserves.)

Goodwill

Goodwill: Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. The amount of goodwill recognized is also impacted by measurement differences resulting from certain assets and liabilities not recorded at fair value (e.g. income taxes, employee benefits). Goodwill is not amortized, but is tested for impairment at a level of a reporting unit at least annually, in the same reporting period each year. Goodwill is included in the line item “Other” assets in the consolidated balance sheets and was $268 million as of December 31, 2021, compared with $269 million at December 31, 2020. A significant majority of the goodwill balance is attributable to the following business combinations within the Aflac U.S. segment, which represents the reporting unit for goodwill impairment testing: (i) CAIC acquisition in 2009, (ii) Empoweredbenefits acquisition in 2015, (iii) Argus acquisition in 2019, and (iv) acquisition of Zurich's business in the fourth quarter of 2020.

Policy Liabilities - Future Policy Benefits

Policy Liabilities: Future policy benefits represent insurance claims that are expected to occur in the future and are computed following a net level premium method using estimated future investment yields, persistency and recognized morbidity and mortality tables modified to reflect the Company's experience, including a provision for adverse deviation. These assumptions are generally established and considered locked at policy inception. These assumptions may only be unlocked in certain circumstances based on the results of periodic DAC recoverability and premium deficiency testing.

Policy Liabilities - Unpaid Policy Claims

Unpaid policy claims are estimates computed primarily on an undiscounted basis using statistical analyses of historical claims experience adjusted for current trends and changed conditions. The ultimate liability may vary significantly from such estimates. The Company regularly adjusts these estimates as new claims experience emerges and reflects the changes in operating results in the year such adjustments are made.

Unearned Premiums

Unearned premiums consist primarily of discounted advance premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as earned premiums over the contractual premium payment period.

Other Policy Liabilities

Other policyholders’ funds liability consists primarily of the fixed annuity line of business in Aflac Japan which has fixed benefits and premiums.

Internal Replacements of Insurance Contracts

For internal replacements that are determined to be substantially changed, policy liabilities related to the original policy that was replaced are immediately released, and policy liabilities are established for the new insurance contract. Further, the policy reserves are evaluated based on the new policy features, and any change (up or down) necessary is recognized at the date of contract change/modification. Examples include conversions to higher age bands, certain family coverage changes, pricing era changes (increase), lapse & re-issue, certain reinstatements and certain other contract conversions. However, for internal replacements that are considered substantially unchanged, no changes to the reserves are recognized.

Reinsurance

Reinsurance: The Company enters into reinsurance agreements with other companies in the normal course of business. For each reinsurance agreement, the Company determines if the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums, benefits and DAC are reported net of insurance ceded.

Income Taxes

Income Taxes: Income tax provisions are generally based on pretax earnings reported for financial statement purposes, which differ from those amounts used in preparing the Company's income tax returns. Deferred income taxes are recognized for temporary differences between the financial reporting basis and income tax basis of assets and liabilities, based on enacted tax laws and statutory tax rates applicable to the periods in which the Company expects the temporary differences to reverse. The Company records deferred tax assets for tax positions taken based on its assessment of whether the tax position is more likely than not to be sustained upon examination by taxing authorities. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized.

Policyholder Protection Corporation and State Guaranty Association Assessments

Policyholder Protection Corporation and State Guaranty Association Assessments: In Japan, the government has required the insurance industry to contribute to a policyholder protection corporation. The Company recognizes a charge for its estimated share of the industry's obligation once it is determinable. The Company reviews the estimated liability for policyholder protection corporation contributions on an annual basis and reports any adjustments in Aflac Japan's expenses.

In the U.S., each state has a guaranty association that supports insolvent insurers operating in those states. The Company's policy is to accrue assessments when the entity for which the insolvency relates has met its state of domicile's statutory definition of insolvency, the amount of the loss is reasonably estimable and the related premium upon which the assessment is based is written. See Note 15 of the Notes to the Consolidated Financial Statements for further discussion of the guaranty fund assessments charged to the Company.

Treasury Stock

Treasury Stock: Treasury stock is reflected as a reduction of shareholders' equity at cost. The Company uses the weighted-average purchase cost to determine the cost of treasury stock that is reissued. The Company includes any gains and losses in additional paid-in capital when treasury stock is reissued.

Share-Based Compensation

Share-Based Compensation: The Company measures compensation cost related to its share-based payment transactions at fair value on the grant date, and the Company recognizes those costs in the financial statements over the vesting period during which the employee provides service in exchange for the award. The Company has made an entity-wide accounting policy election to estimate the number of awards that are expected to vest and the corresponding forfeitures.

Earnings Per Share

Earnings Per Share: The Company computes basic earnings per share (EPS) by dividing net earnings by the weighted-average number of unrestricted shares outstanding for the period. Diluted EPS is computed by dividing net earnings by the weighted-average number of shares outstanding for the period plus the shares representing the dilutive effect of share-based awards.

Reclassifications

Reclassifications: Certain reclassifications have been made to prior-year amounts to conform to current-year reporting classifications. These reclassifications had no impact on net earnings or total shareholders' equity.

Recently Adopted Accounting Pronouncements

New Accounting Pronouncements

Recently Adopted Accounting Pronouncements

ASU 2020-04 Reference Rate Reform: Facilitation of the Effects of Reference Rate Reform on Financial Reporting, as clarified and amended by:

ASU 2021-01 Reference Rate Reform: Relief Extended to Derivatives Impacted by Discounting Transition

In March 2020, the FASB issued amendments that provide optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions affected by the reference rate reform if certain criteria are met. The amendments in this ASU only apply to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate (LIBOR) or another reference rate expected to be discontinued because of reference rate reform.

An entity may elect to apply the amendments as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued.

The amendments generally expire on December 31 2022, i.e., they do not apply to contract modifications made after December 31, 2022, new hedging relationships entered into after December 31, 2022, and hedging relationships evaluated for periods after December 31, 2022.

In January 2021, the FASB issued a standard to permit entities to apply optional expedients in ASC 848 to derivative instruments modified because of discounting transition. Discounting transition refers to the changing of interest rates used for margining, discounting, or contract price alignment of derivative instruments to transition to alternative rates.The amendment is effective immediately.

This standard was adopted on April 1, 2020. The adoption of the new guidance did not have an impact on the Company’s financial statements. The Company will continue to evaluate the impacts of reference rate reform on contract modifications and hedging relationships through December 31, 2022.

ASU 2019-04 Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments

In April 2019, the FASB issued Codification improvements to clarify and correct certain areas of guidance amended as part of ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities; ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments; and ASU 2017-12, Derivative and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities.

The most significant of these improvements to the Company was related to the Codification improvement to ASU 2017-12 and the clarification that a one-time reclassification of assets that are eligible to be hedged under the last-of-layer method (i.e., certain pre-payable securities) from held-to-maturity to available-for-sale is allowed under the new hedge accounting guidance and would not impact the Company’s ability to continue to classify other bonds as held-to-maturity.

The other amendments related to ASU 2017-12 and 2016-01 are either not significant, or were previously implemented as part of the related ASU adoptions.

Applicable amendments related to ASU 2016-13 are discussed within the recent adoption of that update below.

This standard was adopted on January 1, 2020. The adoption of this guidance resulted in a reclassification of $6.9 billion (at amortized cost) of pre-payable fixed-maturity securities from the held-to-maturity to the available-for-sale category. The reclassification resulted in recording in beginning 2020 accumulated other comprehensive income a net unrealized gain of $848 million on an after-tax basis, based on the securities’ fair values on the reclassification date. The reclassification impacted the adoption of ASU 2016-13 (see ASU 2016-13 below for additional details).

ASU 2016-02 Leases, as clarified and amended by:

ASU 2018-01, Leases: Land Easement Practical Expedient for Transition to Topic 842

ASU 2018-10, Codification Improvements to Topic 842, Leases

ASU 2018-11, Leases, Targeted Improvements

ASU 2018-20, Leases: Narrow-Scope Improvements for Lessors

In February 2016, the FASB issued updated guidance for accounting for leases (“Leases Update”). Per the Leases Update, lessees are required to recognize all leases on the balance sheet with the exception of short-term leases. A lease liability will be recorded for the obligation of a lessee to make lease payments arising from a lease. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The Leases Update provided a number of optional practical expedients. The Company elected the "package of practical expedients," which permits the Company not to reassess under the new standard its prior conclusions about lease identification, lease classification and initial direct costs. Under the Leases Update, lessor accounting is unchanged.

This standard was adopted on January 1, 2019. The Company has operating and finance leases for office space and equipment. The Company elected the short-term lease exemption for all classes of leases which allows the Company to not recognize right-of-use assets and lease liabilities on the consolidated balance sheet and allows the Company to recognize the lease expense for short-term leases on a straight-line basis over the lease term. The Company elected the practical expedient to not separate lease and non-lease components and applied it to all classes of leases where the non-lease components are not significant. Some of the Company's leases include options to extend or terminate the lease and the lease terms may include such options when it is reasonably certain that the Company will exercise that option. Certain leases also include options to purchase the leased property. The leases within scope of the leases update increased the Company's right-of-use assets and lease liabilities recorded in its beginning 2019 consolidated balance sheet by $134 million.

As of January 1, 2019, the Company did not have land easements, but has elected the practical expedient as a safe harbor.

The Company elected the optional transition method and as a safe harbor, the practical expedient provided to lessors.

The Company has made an accounting policy election to exclude amounts collected from customers for all sales (and other similar) taxes from the transaction price. The adoption of the Leases Update and related amendments did not have a significant impact on the Company's financial position, results of operations, or disclosures.

ASU 2016-13 Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments, as clarified and amended by:

ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments

ASU 2019-05, Financial Instruments - Credit Losses (Topic 326), Targeted Transition Relief

ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments - Credit Losses

In June 2016, the FASB issued amendments that require a financial asset (or a group of financial assets) measured at amortized cost to be presented net of an allowance for credit losses (Credit Losses ASU) in order to reflect the amount expected to be collected on the financial asset(s). The measurement of expected credit losses is amended by replacing the incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information. Credit losses on available-for-sale debt securities is measured in a manner similar to prior U.S. GAAP; however, the amendments require that credit losses be presented as an allowance rather than as a write-down. Other amendments include changes to the balance sheet presentation and interest income recognition of purchased financial assets with a more-than-insignificant credit deterioration since origination (PCD financial assets).

This standard was adopted on January 1, 2020. The Company recorded a cumulative effect adjustment with a decrease to beginning 2020 retained earnings of $56 million, net of taxes. See Note 3 of the Notes to the Consolidated Financial Statements for credit loss disclosures. The following line items in the consolidated balance sheets were most significantly impacted by the adoption of the new accounting standard:

•Fixed maturity securities held to maturity, at amortized cost

•Commercial mortgage and other loans

•Reinsurance recoverable, included within Other asset

Description of Accounting Pronouncements Pending Adoption

Accounting Pronouncements Pending Adoption

ASU 2018-12 Financial Services - Insurance: Targeted Improvements to the Accounting for Long-Duration

Contracts, as clarified and amended by:

ASU 2019-09 Financial Services - Insurance: Effective Date

ASU 2020-11 Financial Services - Insurance: Effective Date and Early Application

In August 2018, the FASB issued amendments that will significantly change how insurers account for long-duration contracts. The amendments will change existing recognition, measurement, presentation, and disclosure requirements. Issues addressed in the new guidance include: 1) a requirement to review and, if there is a change, update assumptions for the liability for future policy benefits at least annually, and to update the discount rate assumption quarterly, 2) accounting for market risk benefits at fair value, 3) simplified amortization for deferred acquisition costs, and 4) enhanced financial statement presentation and disclosures.

In November 2019, the FASB issued an amendment extending the effective date for public business entities that meet the definition of an SEC filer, excluding entities eligible to be small reporting companies as defined by the SEC, by one year. In November 2020, the FASB issued an amendment providing an additional year deferral for all insurance entities due to the impact of COVID-19. The amendments are now effective for the Company for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2022. Early application of the amendments is permitted.

The Company continues to evaluate the impact of adoption and expects that the adoption will have a significant impact on the Company’s financial position, results of operations, and disclosures. The Company anticipates that the requirement to update assumptions for liability for future policy benefits (LFPB) will have a significant impact on its results of operations, systems, processes and controls and that the requirement to update discount rates will have a significant impact on its equity.

As part of working toward implementation of the updated standard, the Company has made progress on key accounting policy decisions, including processes to identify insurance policy groupings (cohorts) for LFPB measurement and DAC amortization purposes, applicable discount rates, development of liability cash flow and claim expense assumptions, and DAC amortization methodology.

The Company will not early adopt the updated standard and has selected the modified retrospective transition method. Based upon this transition method, the Company currently estimates that the January 1, 2021 transition date (Transition Date) impact from adoption is likely to result in a decrease in accumulated other comprehensive income (AOCI) in a range between $18 billion and $20 billion. This is due to updating the LFPB discount rate assumptions from the rates locked in for reserves held as of the Transition Date to rates determined by reference to the Transition Date market level yields for upper-medium-grade (low credit risk) fixed income instruments (as of December 31, 2020). The variability around the impact of adoption results from the Company making certain estimates, primarily related to the determination of Transition Date market level yields.

The Company has advanced and continues to refine the design of its discount rate methodology for both the U.S. and Japan insurance business. The methodology incorporates constructing a discount rate curve separately for discounting cash flows used to calculate the U.S. and Japan LFPB, with each curve intended to be reflective of the currency, tenor and characteristics of the insurance liabilities. Discount rates comprising each curve will be determined by reference to upper-medium grade (low credit risk) fixed-income instrument yields that are intended to reflect the duration characteristics of the corresponding insurance liabilities. The Company intends to use for these yields single-A rated fixed income instruments with credit ratings based on international rating standards. Where only local ratings are available, the Company intends to select the fixed-income instruments with local ratings that are equivalent to a single-A rating based on international rating standards. The methodology will be designed to prioritize observable inputs based on market data available in the local debt markets where the respective policies were issued in the currency in which the policies are denominated. For the discount rates applicable to tenors for which the single-A debt market is not liquid or there is little or no observable market data, the Company will use various estimation techniques consistent with the fair value guidance in ASC 820, which include, but are not limited to: (i) for tenors where there is less observable market data and/or the observable market data is available for similar instruments, estimating tenor-specific single-A credit spreads and applying them to risk-free government rates; (ii) for tenors where there is very limited or no observable single-A or similar market data, interpolation and extrapolation techniques. Discount rates will be updated each reporting period.

Long duration insurance contracts issued by the Company will be grouped into annual calendar-year cohorts based on the contract issue date, reportable segment, legal entity and product type. Limited pay contracts will be grouped into separate

cohorts from other traditional products in the same manner and will be further separated based on their premium payment structures. Riders will be combined with base policies with similar insurance coverage types and the same contract issue years.

In addition to the preliminary policy elections related to cohorts and LFPB discount rates directly impacting Transition Date AOCI, the Company has also advanced the following accounting policies relevant to the post-Transition Date accounting:

•Cash flow assumptions underlying insurance liabilities will be evaluated as to whether an update is needed at least annually in the same fiscal quarter each year. To facilitate the review, experience studies will be performed annually in the consistent quarter year-to-year to substantiate assumptions, including mortality, morbidity, and terminations in future periods.

•Locked-in discount rates used for the computation of interest accretion on LFPB for policies issued on or after January 1, 2021 will be determined for each issue-year cohort as a single discount rate, calculated as the weighted-average of monthly upper-medium grade (low-credit risk) fixed-income instrument forward curves over the calendar year, determined using the methodology described above and weighted using issued annualized premiums for each issue month. The single discount rate for each issue-year cohort will remain unchanged after the calendar year of issue. Locked-in discount rates on the policies held at Transition Date reflect the locked-in rates in existence immediately before the Transition Date.

•For DAC amortization, the Company has made a preliminary election to group insurance policies into cohorts that are consistent with the groupings used in estimating the associated LFPB. DAC will be amortized on a constant level basis for the grouped contracts over the expected remaining term of the related contracts. For both life and health products issued by Aflac Japan, the constant-level basis used will be units in force, which is a proxy for face amount and insurance in force, respectively. For life products issued by Aflac U.S., the constant level basis used will be face amount of policies in force; for health products issued by Aflac U.S., the constant level basis used will be the number of policies in force.

•The Company has made a preliminary entity-wide election to use locked-in claim expense assumptions determined for each issue-year cohort as a percentage of incurred claims; these assumptions would remain unchanged over the term of the insurance policy.

The Company has created a governance framework and a plan to support implementation of the updated standard. As part of its implementation plan, the Company has also advanced the modernization of its actuarial technology platform to enhance its modeling, data management, experience study and analytical capabilities, increase the end-to-end automation of key reporting and analytical processes and optimize its control framework. The Company has also put in place internal controls related to the new processes created as part of implementing the updated standard and will continue to refine and maturate these internal controls until the formal implementation in the first quarter of 2023.

The Company has recently begun testing its reporting and disclosure capabilities under the new ASU for post-Transition Date accounting periods.

The Company currently has no products with market risk benefits.