In Moore v. U.S., Mr. and Mrs. Moore challenge the constitutionality of the transition tax under § 965. The Moores ask the Supreme Court to reaffirm a realization requirement for income taxable under the Sixteenth Amendment. The Moores argue that this realization requirement applies to § 965 and that §965, as a tax on unrealized gain, is unconstitutional. In contrast, the government argues that the transition tax is a permissible extension of tax regimes like Subpart F that already tax undistributed corporate earnings. (See our recent client alert on the case generally.)
A ruling on the realization requirement bears on whether Pillar Two might be constitutional in the United States. Specifically, a ruling that § 965 does not comply with a realization requirement, if not suitably cabined, could imperil the ability of the U.S. to implement Pillar Two legally, because Pillar Two might be viewed as similarly not complying with the realization requirement.