Same-sex marriages in Indiana became lawful following the U.S. Supreme Court’s decision not to act on a petition for review of a decision by the 7th Circuit Court of Appeals that had upheld a district court decision striking down Indiana’s ban on same-sex marriage (Baskin v. Bogan, 12 F. Supp. 3d 1144 (S.D. Ind. 2014)).
Reciprocity. Same-sex and opposite-sex marriages legally performed in other jurisdictions are recognized as legal marriages in Indiana.
The U.S. Supreme Court subsequently issued a decision legalizing same-sex marriage in all states and requiring all states to recognize same-sex marriages legally performed in other jurisdictions (Obergefell v. Hodges, 135 S.Ct. 2584 (2015)).