On June 26, 2013, the United States Supreme Court overturned Section 3 of the Defense of Marriage Act (“DOMA”), which required the federal government to deny married same-sex couples the rights and benefits provided to married heterosexual couples. DOMA also provided states with the authority to refuse to recognize the marriages of same-sex couples from other states. In United States v. Windsor, the Supreme Court held that the federal government must recognize same-sex marriages performed by states (and perhaps foreign jurisdictions). Thirteen U.S. states, four Native American tribal nations, and fourteen foreign countries currently allow same-sex marriages. The remaining U.S. states are divided between those with laws prohibiting the recognition of same-sex marriages, and those which may recognize same-sex marriages performed in other states.

However, the ruling does not appear to require states to recognize a valid marriage of a same-sex couple performed in another state. Nor is it clear what the effective date of the tax effects are, to what extent this ruling is retroactive, or which, if any, of the federal rights relating to marriage will be provided to same-sex married couples who live in states that do not perform or recognize same-sex marriages. It is also not clearly resolved in which cases a benefit plan is required, versus being allowed, to recognize same-sex marriages. The IRS or Department of Labor may issue regulatory guidance to clarify these issues. In addition, the Windsor case did not speak to domestic partnerships or civil unions, but the federal Office of Personnel Management takes the position that generally the change is applicable for same-sex married couples, but not for those in domestic partnerships or civil unions.