It's the millions of taxpayers that fall somewhere in between who increasingly get ensnared.
Middle-income taxpayers most vulnerable to AMT include those with many children, since personal exemptions disappear, married taxpayers, since the "marriage bonus that applies to regular income tax is disallowed, and those who claim miscellaneous itemized deductions, such as medical or dental expenses. Taxpayers who exercise incentive stock options, realize significant capital gains or live in a high-tax state are also often subject to the AMT, since state and local tax is not deductible under the AMT.
In 2013, for example, a married couple earning $400,000 with two children and $80,000 in itemized deductions, including $20,000 in property taxes and $23,000 in state income taxes, would be subject to AMT of $8,890 on top of their ordinary income tax, according to Mark Luscombe, principal tax analyst for CCH in Riverwoods, Ill. But a taxpayer with property taxes of $5,000 and state and local sales taxes of $5,000 would be exempt from the AMT.
Any taxpayer could be caught by the AMT, but Lauridsen said households earning $75,000 or more that claim at least one of the deductions that are excluded under the AMT should err on the side of caution and fill out the form.
Households earning more than $150,000, regardless of how many exemptions and deductions they claim, should also fill out the form.
If you owed AMT last year, chances are you'll owe it again, said Luscombe.
If you've never paid it before but fear you've tipped the scales this year with higher income or a set of triplets, grab a pencil, your 1040 and a double shot of espresso. It's time to get busy.
(Read more: 8 things you need to know about tax reform)