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Although same-sex marriage is now legal in nine U.S. states and the District of Columbia, it is still illegal in the United States. And for the purposes of filing a federal tax return, same-sex couples are faced with a choice of lying or, very likely, paying more federal income tax than opposite-sex married citizens.

That could change later this year, after the U.S. Supreme Court rules on the constitutionality of the Defense of Marriage Act (DOMA) in a case brought by Elizabeth Windsor, the 83-year-old survivor of a same-sex marriage who sued after she was slapped with a federal estate tax bill for $363,000 following the death of her wife in 2009.

Until the DOMA is struck down (if it is — and that’s a big if), there are few avenues of recourse for same-sex couples when filing their federal tax returns. The website Refuse to Lie (refusetolie.org) offers a few suggestions.

The first suggested option is to put an asterisk by the box on the tax form and in a footnote “indicate you are only single under DOMA.” Alternatively, the website offers an explanatory note that filers could attach to the return.

A third option is to take advantage of a section of the Internal Revenue Service code that provides “no penalty shall be imposed [for the underpayment of tax] if … there is reasonable cause for [the underpayment] and the taxpayer acted in good faith ….” This might work because U.S. Attorney General Eric Holder has argued against the constitutionality of the DOMA and that “would seem to provide a reasonable legal opinion.”

It is equally likely not to work because President Obama, despite his recently found support for declaring DOMA unconstitutional, has directed federal departments to obey the law of the land, currently DOMA.

Perhaps the best alternative that Refuse To Lie suggests is to file as a married couple because “no penalty is imposed unless the taxpayer’s reporting position resulted in an under-reporting of the tax liability” if the couple pays more than they would if each filed singly. The catch is that it is far more likely that a same-sex couple filing separately will pay more than a married couple.

There is no sure way out of the federal tax dilemma faced by same-sex couples unless and until DOMA is overturned or repealed by Congress.