The Alternative Minimum Tax is a parallel tax system which does not permit several of the deductions permissible under the regular tax system, such as property tax and state income tax. Taxpayers who may be subject to the AMT must calculate their tax liability under the regular federal tax system and under the AMT system taking into account certain “preferences” and “adjustments.” If their liability is found to be greater under the AMT system, that’s what they owe the federal government.
Originally enacted to make sure that wealthy Americans did not escape paying taxes, the AMT has started to apply to more middle-income taxpayers, due in part to the fact that the AMT parameters are not indexed for inflation.
In recent years, Congress has provided a measure of relief from the AMT by raising the AMT “exemption amounts”— allowances that reduce the amount of alternative minimum taxable income (AMTI), reducing or eliminating AMT liability. However, these exemption amounts are phased out for taxpayers whose AMTI exceeds specified amounts.
For 2009, the AMT exemption amounts were $70,950 for married couples filing jointly and surviving spouses; $46,700 for single taxpayers; and $35,475 for married filing separately. However, for 2010, those amounts were scheduled to fall back to the amounts that applied in 2000: $45,000, $33,750, and $22,500, respectively. This would have brought millions of additional middle-income Americans under the AMT system, resulting in higher federal tax bills for many of them, along with higher compliance costs associated with filling out and filing the complicated AMT tax form. See previous Blog posts for 2010 exemptin amounts.