The U.S. Department of the Treasury and the Internal Revenue Service (IRS) today ruled that same-sex couples, legally married in jurisdictions that recognize their marriages, will be treated as married for federal tax purposes. The ruling applies regardless of whether the couple lives in a jurisdiction that recognizes same-sex marriage or a jurisdiction that does not recognize same-sex marriage.

The ruling implements federal tax aspects of the June 26 Supreme Court decision invalidating a key provision of the 1996 Defense of Marriage Act (DOMA).

Under the ruling, same-sex couples will be treated as married for all federal tax purposes, including income and gift and estate taxes. The ruling applies to all federal tax provisions where marriage is a factor, including filing status, claiming personal and dependency exemptions, taking the standard deduction, employee benefits, contributing to an IRA and claiming the earned income tax credit or child tax credit.

Any same-sex marriage legally entered into in one of the 50 states, the District of Columbia, a U.S. territory or a foreign country will be covered by the ruling. However, the ruling does not apply to registered domestic partnerships, civil unions or similar formal relationships recognized under state law.

Legally married same-sex couples generally must file their 2013 federal income tax return using either the married filing jointly or married filing separately filing status.

Individuals who were in same-sex marriages may, but are not required to, file original or amended returns choosing to be treated as married for federal tax purposes for one or more prior tax years still open under the statute of limitations.

Generally, the statute of limitations for filing a refund claim is three years from the date the return was filed or two years from the date the tax was paid, whichever is later. As a result, refund claims can still be filed for tax years 2010, 2011 and 2012. Some taxpayers may have special circumstances, such as signing an agreement with the IRS to keep the statute of limitations open, that permit them to file refund claims for tax years 2009 and earlier.