A person married to a U.S. citizen may pursue permanent residence through that family relationship. The case will always involve at least two phases: one for the U.S. citizen spouse to petition the government to recognize the family relationship and to classify the foreign national spouses as the “immediate relative” of a U.S. citizen, and another for the foreign national to actually apply for the permanent residence benefit.
If the foreign national spouse is outside the U.S., perhaps because she has never been to the U.S. in her life, or perhaps because she returned abroad after a temporary stay in the U.S., she will need to apply for an immigrant visa at the U.S. consulate in her country after the immediate relative family petition is approved. The consulate does background checks to make sure the foreign national spouse is not barred from obtaining permanent residence by a criminal background, misrepresentation, previous immigration violation, or other ground, and requires a medical exam to demonstrate the foreign national has been vaccinated and is not barred by substance abuse issues. The consulate also checks for proof that the marriage underlying the immigrant visa application was entered into in good faith.
On the other hand, if the foreign national spouse is inside the U.S., he may apply for adjustment of status to permanent residence at the same time (“concurrently”) with the immediate relative petition. Call it a two-step! Adjustment of status requires that the foreign national spouse show he entered the U.S. with inspection by border officials and that he is not inadmissible, or ineligible according the government regulations for permanent residence.