If an individual marries a US citizen, he or she may apply for permanent residence (green card) and obtain a work permit.
If the spouse is located outside of the US, the US citizen may apply for a K3 visa to allow the spouse to enter the US and obtain permanent residency. If the couple is not yet married and the foreign fiancé(e) is located outside of the US, then a K1 visa is appropriate.
If the spouse is located in the US, the US citizen may sponsor the spouse for permanent residency, as long as the spouse entered the US legally, and obtain a work permit and advance parole.
Spouses of US citizens who wish to obtain permanent residence in the US
In order to obtain immigration benefits available to a spouse, there must be a valid marriage between the parties. In most situations, a marriage is valid for immigration purpose if it is recognized by the law of the state where it occurs. However, a marriage that is legally valid may still be disregarded if it is found to be a sham marriage, entered into by the parties to obtain immigration benefits and without any intention to live together as husband and wife. The marriage must also be legally subsisting at the time that the immigration benefit is sought with an exception where the US citizen is deceased.
Either the US citizen must also provide an affidavit of support, guaranteeing the support the immigrant spouse for at least 10 years or until the beneficiary becomes a US citizen. In order to guarantee this support, the sponsor must meet the annual income requirement of 125% of the current federal poverty guidelines or show that he or he has enough assets to support the immigrant spouse. If the sponsor cannot meet this income requirement, then he or she may find other joint sponsors.