Many taxpayers must calculate their federal income tax liability under two sets of rules: those applying to the regular income tax and those of the alternative minimum tax. If a taxpayer owes more tax under the alternative rules, then the difference is paid as AMT. The AMT hits people in some states harder than it does in others because state and local income and property taxes are not allowed as itemized deduction against the AMT and because states vary based on the income of their residents. This column discusses AMT participation rates by state and the general expansion of the AMT across all the states.

Many taxpayers must calculate their federal income tax liability under two sets of rules: those applying to the regular income tax and those of the alternative minimum tax. If a taxpayer owes more tax under the alternative rules, then the difference is paid as AMT. The AMT hits people in some states harder than it does in others because state and local income and property taxes are not allowed as itemized deduction against the AMT and because states vary based on the income of their residents. This column discusses AMT participation rates by state and the general expansion of the AMT across all the states.

The individual alternative minimum tax (AMT) was originally enacted in 1969 to guarantee that high-income individuals paid at least a minimal amount of tax. Middle- and upper-income taxpayers must add a number of so-called preference items to their taxable income, subtract a special AMT exemption, and calculate their tax according to the AMT tax schedule. If the tax under that schedule is higher than the regular income tax, taxpayers pay the difference as AMT. This document outlines 11 key facts and projections about the AMT, including its effects on taxpayers and prospects for its reform.