Taxes after marriage
April 6, 2012
I've always assumed there was some sort of tax benefit to filing U.S. federal taxes jointly with a partner. Now that I'm filing taxes for the first time after getting married, however, I see that it's not so simple. There is a tax benefit if two partners have disparate individual incomes, but there is a penalty if both partners have roughly equal incomes. The following graphic shows the difference in the taxes between filing jointly and separately as percentage of joint income:
The values represented in the diagram are the difference between the total amount of taxes that a couple would owe (with the 2011 federal U.S. tax schedule) if they were to file jointly or file separately, given as a percentage of the couple's total income. For example, if the lower-earning partner earns $25,000 and the higher-earning partner earns $75,000 they owe $18,200 if filing separately and $17,250 if filing jointly, resulting in a marriage benefit of $950, or about 1% of their total income.
A little googling revealed that the whole “marriage penalty, marriage benefit” story isn't quite so simple; for example, married couples filing jointly can enjoy preferential estate-tax treatment. However, if the benefits of filing jointly are not relevant, many married couples may pay less tax by filing separately.