See Federal Tax Return Guidelines for Same-Sex Married Couples for the latest update from the IRS.
Can same-sex married couples file amended federal income tax return/refund claims based on the Supreme Court’s decision in United States v. Windsor or the Defense of Marriage Act (DOMA)?
The federal recognition of same-sex marriages means gay couples could be entitled to tax refunds for filing situations for which married couples receive tax breaks.
Usually the Internal Revenue Service (IRS) does not allow a change in filing status after an original return is filed. To my knowledge, the IRS has not yet announced how it will handle income tax refund claims based on a retroactive change in filing status. However, I would advise such couples to quickly file amended return/refund claims because I do not believe the Court’s decision affected the statute of limitations on refund claims, which is usually the later of thee years from when the return was originally due or two years from when the tax was paid.
See my posting on the Tax Implications of DOMA for more information on income tax and estate and gift tax issues.