The IRS has issued final regulations clarifying the definitions of “spouse,” “husband,” “wife,” and “husband and wife” for federal tax purposes. The final regulations now define “spouse,” “husband” and “wife” as any individual lawfully married to another individual, and “husband and wife” as any two individuals lawfully married to each other, regardless of the individuals’ sex.

The clarification was needed after the Supreme Court ruled in Obergefell v. Hodges in 2015 that state bans on same-sex marriage violated the Equal Protection guarantees of the Fourteenth Amendment. Obergefell struck down same-sex marriage bans as unconstitutional in four states (Ohio, Michigan, Kentucky and Tennessee), resolving a circuit split on the issue. (As previously discussed here, the Obergefell decision was anticipated after the Court ruled in U.S. v. Windsor that the authority to define marriage lay with the states, but declined to rule on the constitutionality of same-sex marriage. For more on the Windsor case, click here.)

Following Obergefell, the IRS issued proposed regulations redefining “spouse” for federal tax purposes. The proposed regulations also provided that a recognized marriage for federal tax purposes was a marriage recognized by any U.S. state, possession or territory. However, commentators pointed out that such a definition was too broad. For example, the proposed regulations’ definition of marriage could have caused taxpayers living in common-law marriages not recognized by their state to nonetheless be treated as married if any other U.S. state or territory would recognize their marriage. As a result, the final regulations provide that a marriage is recognized for federal tax purposes if the marriage is recognized in the U.S. state, possession or territory where the marriage is entered into – also known as the “state of celebration” rule. The final regulations do not recognize as a marriage for federal tax purposes alternative legal relationships such as registered domestic partnerships or civil unions. The final regulations also contain rules on recognition of foreign marriages. The full text of the final regulations can be found here.

These regulations should offer clarity to same-sex partners for estate and tax planning matters.