Edith Windsor married Thea Spyer in Canada, and New York recognized the marriage. After Spyer died, Windsor paid $363,053 in federal estate taxes because Section 3 of the Defense of Marriage Act (DOMA) excluded same-sex spouses from federal recognition and denied her the marital exemption. The Internal Revenue Service rejected Windsor’s refund claim, and she sued. Although the United States agreed that DOMA Section 3 was unconstitutional, it continued enforcing the provision and refused to pay the refund, leaving a live controversy. The Supreme Court held that the parties could appeal and that Section 3 violated the Fifth Amendment. DOMA’s federal definition of marriage demeaned same-sex couples whose marriages States had recognized, imposed unequal rights and responsibilities across federal law, and lacked a constitutionally sufficient relation to the asserted interests. The Court affirmed the judgment ordering the refund. It did not decide the validity of DOMA Section 2 or whether the Constitution independently requires States to recognize same-sex marriage. The majority’s judgment was accompanied by dissents from the Chief Justice, Justice Scalia, and Justice Alito.