The outcome of the same-sex marriage estate tax case United States v. Windsor in the U.S. Supreme Court will present challenges to estate and tax practitioners if Section 3 of the Defense of Marriage Act is ruled unconstitutional (United States v. Windsor, U.S., No. 12-307, oral argument scheduled 3/27/13).

Oral argument in the case is scheduled for March 27, and the court's decision could affect federal rights for same-sex couples in connection with tax and estate planning issues.

In June 2012, the U.S. District Court for the Southern District of New York granted summary judgment to Edith Windsor and held that the $363,053 she was required to pay as executor of the estate of her wife, Thea Spyer, was improperly assessed because of the definition of marriage in the Internal Revenue Code required under DOMA (Windsor v. United States, 833 F. Supp. 2d 394 (S.D.N.Y. 2012); 110 DTR K-1, 6/8/12).