Sen. Ben Cardin (D-Md.) on Monday pressed for the Internal Revenue Service to clarify whether it will allow legally married same-sex couples to file joint tax returns, calling for action in letters to the heads of the IRS and Treasury Department.

“American taxpayers need clarity and they need it quickly,” Cardin said in a statement. “We cannot leave so many taxpayers in limbo, if not financial jeopardy.”

The Supreme Court decision overturning part of the Defense of Marriage Act this year raised questions about how the federal government would treat same-sex couples whose home states don’t recognize gay marriage.

(Shannon Stapleton/Reuters) (Shannon Stapleton/Reuters)

The Pentagon, the Office of Personnel Management  and the Social Security Administration addressed that issue by extending federal benefits to same-sex spouses of federal employees and military personnel regardless of their states of residency. But the IRS has yet to issue guidance for how the court’s decision will affect its policies.

Cardin, a member of the Senate committee that oversees the IRS, said the agency should recognize same-sex marriages even if they are registered outside the couples’ state of residence. “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,” he said.

Cardin also called on the IRS to clarify whether it would allow couples involved in civil unions to file joint returns. He noted that eight states treat civil unions the same as legal marriage in terms of legal rights, but he did not take a definitive stance on how the IRS should treat such partnerships.

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