Consider a couple living in New York state with each earning $280,000 in annual wages -- for a combined $560,000. The couple will pay about $22,000 more in taxes this year if they are married filing jointly than if they were single, according to an analysis by Perry. That assumes each of them has $20,000 in capital gains and dividends as well as $35,500 each in deductions for charitable contributions, mortgage interest and real estate taxes.

Personal Exemptions

As a married couple, more of their income is subject to the phase-outs on personal exemptions and limits on itemized deductions as well as the higher taxes on wages and investment income from both the health-care law and budget deal.

“They made it worse because of where they set the brackets,” Perry said of the marriage penalty as it applies to high-earning, married couples.

That’s because the thresholds for individuals and married couples at the higher rates are close together, said Scott Kaplowitch, a partner at the Boston-based accounting firm of Edelstein & Co. LLP.

“$50,000 isn’t really a big spread,” Kaplowitch said. “People may just cohabitate because it’s better from a tax perspective.”

Varying Rates

Penalties -- and bonuses -- for being married or single have existed in the tax code for decades because the system is based on household income and the rates vary, said Eugene Steuerle, co-founder of the Washington-based Tax Policy Center.

Lawmakers have adjusted since the 1940s where to set income- tax brackets to address inequities among different types of families including married couples and singles, said Dennis Ventry, a professor at the University of California, Davis School of Law who specializes in family taxation. Families often feel the so-called marriage penalty if they don’t account for it when deciding how much to withhold from their paychecks throughout the year for taxes, Ventry said.

The marriage penalty also affects lower-income households who may phase out of benefits such as the earned income tax credit because as a couple their income is too high, he said.