Congress changed the AMT exemption slightly. For individuals, the exemption increases to $44,350 in 2007 from $42,500 in 2006, and for married couples, the exemption climbs to $66,250 from $62,550. This change will mean that some 25 million filers will
avoid the AMT on their 2007 income, up from 4 million who paid it on 2006 income.

Enacted in 1969 to prevent very wealthy investors from using deductions and tax shelters to avoid paying income tax, the AMT has hit a growing number of middle-class tax payers because the 1969 law was not indexed to inflation. Paying the AMT means you lose deductions like high medical expenses and state and local taxes and credits for dependents.