26 U.S.C. § 843 (2024) — Annual accounting period

For purposes of this subtitle, the annual accounting period for each insurance company subject to a tax imposed by this subchapter shall be the calendar year. Under regulations prescribed by the Secretary, an insurance company which joins in the filing of a consolidated return (or is required to so file) may adopt the taxable year of the common parent corporation even though such year is not a calendar year.