WASHINGTON (AP/WZZM) - The government is issuing the regulations needed to allow gay couples married in 13 states that recognize same-sex marriages to file joint federal tax returns.

Treasury Secretary Jacob Lew says the new rules will provide "clear, coherent tax filing guidance for all legally married same-sex couples nationwide."

Lew said the regulations also make clear that legally married same-sex couples will be able to move freely throughout the country and their federal tax filing status will not change.

Essentially, the federal government will recognize their marriage wherever they go. But what about state-tax returns? CPA Thomas Jeakle with Grand Rapids-based Prangley Marks, UP says it will be interesting to see what the states do.

"A lot of states follow the federal tax code and allow you to do whatever you do on the federal return we allow you to do," he said."It remains to be seen what some of these states, including Michigan are going to do, are they going to let you file a federal joint return and then force you to file separate Michigan returns? Could happen."

The new guidelines will apply to all federal taxes, including income, gift and estate taxes, except for social security.

The new rules implement the tax aspects of the Supreme Court's ruling in June which invalidated a section of the 1996 Defense of Marriage Act.

The new regulations from Treasury and the Internal Revenue Service implement the court's decision on how legally married same-sex couples should be treated for federal tax purposes.

For more a complete look at the changes, click on the link to the U.S. Department of Treasury.