The A.M.T. is a parallel system for calculating tax liability intended to ensure that high-income taxpayers pay a substantial amount in federal tax even if they have large deductions or other items to offset income.

Losses from partnerships and limited-liability companies, the entities through which the Trumps report much of their income, do not have to be added back as part of the A.M.T. calculation.

The A.M.T. is much reviled by tax experts across the political spectrum for its unintended consequences and fiendish complexity.

James B. Stewart Quotes