By Cherri Gregg

PHILADELPHIA (CBS) – The IRS and Treasury Department announced this week that the U.S. tax code has been changed to recognize legally married same-sex couples. One local expert discussed what that’ll mean in Pennsylvania.

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“This is a huge win, huge,” says Angela Giampolo, a Philadelphia attorney who specializes in LGBT rights. “Out of the 1,138 federal rights that are bestowed upon married people- the Treasury department has 200 sitting within it.”

Giampolo says the new IRS rules means gay couples legally married in any of the 13 states that recognize same-sex marriage can now file taxes jointly for 2013 even if they live in states like Pennsylvania that ban gay marriage. The new rules will not apply, however, to the same-sex couples who received marriages licences in Montgomery County earlier this year.

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“Until we get some guidance on Pennsylvania’s DOMA, the people married here in Pennsylvania in Montgomery County see no benefit at either the state or federal level,” says Giampolo.

For gay couples with legally valid marriages, the new tax benefits are limited to federal taxes and there could be a downside, especially for high earners.

“With gay marriage comes a cost,” says Giampolo, “straight couples have known this for years. There is a the marriage bonus and then there’s the marriage penalty.”

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There’s also the opportunity to get refunds dating back up to three years. Giampolo recommends that couples get advice from a tax professional who is familiar with the new laws.