Senator Ben Cardin, D-Md., a member of the Senate Finance Committee, has written to Treasury Secretary Jack Lew and Acting IRS Commissioner Daniel Werfel, urging them to quickly resolve and clarify the tax implications for legally married same-sex couples and those in civil unions.

The letter addresses the Supreme Court decision in U.S. v. Windsor, which found section 3 of the Defense of Marriage Act to be unconstitutional. Since the landmark June 26 decision, same-sex couples holding a valid U.S. state or foreign country-issued marriage license are now recognized as married under federal law, and considered a spouse as referenced in the Tax Code. In the letter, Cardin asks the IRS to promptly confirm this filing status by issuing guidance to eventually become a separate IRS publication.  

Cardin also outlines other related issues to be resolved by such guidance.

“American taxpayers need clarity and they need it quickly. The midyear decision by the Supreme Court in the Windsor case was welcome news, but we cannot leave so many taxpayers in limbo, if not financial jeopardy,” Cardin said in a statement. “Central to clarifying how the IRS will handle this transition period should be following the IRS’ own precedent of recognizing a marriage that is lawful in the ‘state of celebration,’ whether or not the state they live in recognizes the marriage. It is not only the fair thing to do but it will maintain the uniformity of the Tax Code for same-sex and opposite-sex couples, as the Court intended.”

In addition to resolving the “state of celebration” rule, Cardin asks the IRS to address retroactivity, by allowing taxpayers to voluntarily amend past returns, though he deems it “inappropriate for the Service to audit, make assessments, to otherwise challenge such a couple’s decision not to amend their returns.”

Finally, Cardin urges the IRS to explain whether those who are in civil unions and thus “spouses,” as recognized by their state, will be treated as married for federal tax purposes