Individuals who have married an American citizen may apply for marriage-based visas in addition to other pathways to legal residency. There are specific requirements for each type of benefit for which petitioners apply.
One route is to petition for a family-based visa at the consulate where the immigrant spouse is located. If the person originally entered the United States illegally and has been in the country for more than six months, he or she can apply for a waiver. However, the threshold for being approved for this waiver is high; the person must show that being denied the visa would result in extreme hardship to the United States citizen spouse or parent. If the individual chooses to stay or return to his or her native country, a visa application can be submitted, and the individual can wait on regular consular processing for family petitions.
Another option is to apply for a relative petition and an adjustment of status. This process involves submitting a petition that shows the marriage relationship to immigration officials. For the I-130 petition, the immigrant and his or her spouse complete biographical data and demographic information about themselves. The I-485 petition is for the adjustment of status from some legal form of immigration to a permanent resident. This process is more involved and requires the couple to submit documented evidence of their relationship, their marriage certificate, passport photos, a physical examination, biometric information and other documents required by USCIS. This process is available for individuals who are currently out of status, as well. However, these individuals must use this option, or they will be barred from reentering the United States for up to ten years if they leave before approval.
Individuals who are not sure about their options may speak with an immigration lawyer. He or she may be able to highlight the benefits and risks associated with each option.
Source: Immihelp, "Marriage Based Green Card for Persons Already in the U.S.", October 21, 2014