The IRS and the U.S. Department of Treasury announced today that they will recognize same-sex marriage for federal tax purposes. The announcement states that they will recognize the marriage, as long as the couple is married in a state that recognizes same-sex marriages. Same-sex couples will have to file as married even if they no longer live in a state that recognizes same-sex marriage. The announcement states that recognition applies only to marriage and does not apply to civil unions, domestic partnerships, or similar formal relationships under state law.
Married same-sex couples are required to file as married beginning with the 2013 tax year. If desired, couples can also amend their last three years of tax returns. The announcement is located, here.
If you have any questions about this announcement, please do not hesitate to contact a tax professional.