For married taxpayers filing a joint return, the phase-out begins at $110,000.

For married taxpayers filing a separate return, it begins at $55,000.

For married taxpayers who file jointly, the exemption is $500,000.

Those who made more, and married taxpayers who filed separately, were ineligible.

For married taxpayers, expenses are limited to the earned income of the lower-earning spouse.

Then that - much higher - income total is subjected to tax, less a $45,000 deduction for married taxpayers filing jointly.

The exclusion is phased out for married taxpayers as their adjusted gross income increases from $60,000 to $90,000.

Before that, the tax code's treatment of married and single taxpayers was straightforward.

But some married taxpayers get a bonus instead of a penalty.

For married taxpayers filing jointly, the exclusion is $500,000.