The Supreme Court's decision in U.S. v. Windsor invalidated the federal definition of marriage and spouse under the Defense of Marriage Act (DOMA), altering employer obligations regarding same-sex marriages. The decision will require employers to provide same-sex spouses equal access to benefits like health insurance, family medical leave, COBRA, and pension plans. However, many questions remain unanswered, like which state's marriage recognition laws will determine federal benefits and whether benefits will apply retroactively. Employers should begin reviewing policies to identify changes needed to comply with the new landscape while guidance is still pending on open issues.