A very common family petition is by one U.S. citizen spouse for the other spouse so that he or she may obtain their lawful permanent residence or “Green Card.” This can be done when the spouse is here in the United States or abroad.
When the spouse is inside the United States, often times they can Adjust Status, or obtain their Green Card after an interview inside the United States at the offices of the immigration department, known as United States Citizenship and Immigration Services.
If they are outside the United States, they process as an Immigrant at the U.S. Consulate inside their country. This is called Consular Processing.
If the spouse is inside the United States but did not enter the United States legally, the spouse may need to obtain a Waiver of Inadmissibility and Consular Process. It is very important to speak with an immigration attorney before thinking of leaving the country. If the spouse needs a Waiver of Inadmissibility, that is a a separate process that is quite complicated but is necessary before the spouse can receive his or her Green Card.
Regardless of how the Green Card is obtained, it is a necessary step before an Immigrant can apply for citizenship.