For many decades, U.S. citizens or lawful permanent residents who were married or engaged to foreign-born same-sex spouses were unable to petition for them to receive either marriage-based U.S. lawful permanent residence (a green card) or K-1 fiance visas (which lead to a green card).
By striking down major portions of the federal Defense of Marriage Act (DOMA), however, in a case called U.S. v. Windsor, the U.S. Supreme Court in 2013 removed the only obstacle blocking visa and green card rights for same-sex couples.
At the core of this issue is the definition of "marriage" under federal law. Under the "Defense of Marriage Act" (DOMA), a relationship previously counted as a "marriage" only if it was between "man and woman."
Oddly enough, marriage is hardly defined at all under federal immigration law, which is why the DOMA definition governed immigrants' rights and opportunities for years.
Section 101(a)(35) of the Immigration and Nationality Act (I.N.A.) (or 8 U.S. Code § 1101(a)(35)), for instance, says only, "The term 'spouse,' 'wife,' or 'husband' does not include a spouse, wife, or husband by reason of any marriage ceremony where the contracting parties thereto are not physically present in the presence of each other, unless the marriage shall have been consummated."
In other words, the main definition of "spouse" found in U.S. immigration law is focused on making sure proxy marriages, where the couple aren't in the same room for the ceremony, don't give anyone marriage rights. Nothing in the definition mentions opposite versus same-sex couples.
The Windsor case challenged DOMA, however—and caused portions of it to be overturned on Constitutional grounds.
In the words of Justice Kennedy, who wrote the Windsor opinion: "No legitimate purpose overcomes the purpose and effect to disparage and to injure those whom the State, by its marriage laws, sought to protect in personhood and dignity. By seeking to displace this protection and treating those persons as living in marriages less respected than others, the federal statute is in violation of the Fifth Amendment."
If you are a non-citizen in a same-sex relationship with a U.S. citizen or permanent resident, everything you read about the rules for marriage-based visas or green cards should apply to you, too.
As with opposite-sex marriages, you will need to prove that the marriage is legally valid in the state or country where it occurred. This led to some initial complications after Windsor, because not all U.S. states authorized same-sex marriages.
However, two years later, in 2015 the U.S. Supreme Court declared that same-sex marriage is legal nationwide, in a landmark decision called Obergefell v. Hodges. The Court found that same-sex couples have a constitutional right to marry under the 14th Amendment and that states cannot ban same-sex marriage.
Of course, there are still many countries around the world that don't allow same-sex marriage, and from which travel might be difficult for the foreign-born half of the couple. Whatever you do, don't try to get around this issue by using a tourist visa to enter the United States.
As with opposite-sex marriages, you will also need to be ready to provide a lot of evidence showing that your marriage is "bona fide" or the real thing, not just a sham to get the foreign-born person a green card. Be prepared to document that you are sharing a life, such as in matters of housing, finances, joint obligations and benefits (such as health or car insurance) and children.
And, as with opposite-sex marriages, you'll have to come to terms with the fact that you're up against a huge government bureaucracy and a tangled set of laws, which can make actually obtaining the visa or green card you deserve very difficult—particularly if the noncitizen entered the U.S. unlawfully.
If you are in deportation (removal) proceedings, your marriage will now work as a defense, and you can apply for a green card through the immigration court system. But if you get married after proceedings have begun, your marriage will be given extra scrutiny to make sure it's the real thing.