Gay-rights supporters are celebrating a U.S. Supreme Court ruling that the federal government may not restrict the definition of marriage to opposite-sex couples.
The court ruling means legally married gay couples are entitled to claim the same federal benefits available to heterosexual married couples, such as tax, health and pension benefits.
The decision invalidated a provision of the federal Defense of Marriage Act, but does not require individual states to recognize same-sex marriages that may be legal in other states.
Same-sex marriage is legal, or soon will be, in 13 states and the District of Columbia.
In another case, the court said a lower-court ruling that struck down a California same sex-marriage ban could not be appealed, meaning gay marriages may resume in the state.
The High Court did not rule on the overall validity of gay marriage bans in California, though, or three dozen other states.
The justices' decisions, both on a 5-4 vote, were announced in their last session before the court's summer break.
The 1996 federal marriage law, known by its acronym DOMA, defined marriage as between a man and a woman. In 2011, the Obama administration abandoned its defense of the law, but continued to enforce it.
Following Wednesday's decision, President Barack Obama said the court "has righted a wrong, and our country is better off for it." He added that the decision applies only to civil marriages and does not change how religious institutions define and consecrate marriage.
Same-sex marriages are legal in California, Connecticut, Delaware, the District of Columbia, Iowa, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New York, Rhode Island, Vermont and Washington.