Individuals who are eligible for permanent resident status and are presently in the United States can file an application to adjust status (obtain a greencard) with U.S. Citizenship and Immigration Services (USCIS). To be eligible for this benefit, a visa should be available through an approved petition from a family member or employer.
The main requirement to adjust status is to prove that an applicant entered with admission or inspection into the United States. In other words, the applicant should be ready to prove that they came through an airport or through a port of entry at the border and presented themselves to immigration officials.
The USCIS officer reviewing the application will also check the criminal and immigration history to ensure that the applicant has not committed any acts that constitute a ground of inadmissibility. For instance, if the applicant has committed fraud or misrepresentation, a drug-related crime, a crime involving moral turpitude, or an immigration violation, USCIS can deny the application. In some cases, a waiver may be available. In some cases, the application may be denied, and USCIS can refer the individual to Immigration Court to have their case heard before an Immigration Judge.
Individuals with special visas, such U status (victims of crimes who cooperated with law enforcement) or Special Juvenile Immigrant Status (children who were abandoned, neglected, or abused by one or both parents) are allowed to adjust status, too.
It is important that you are honest and forthcoming with your attorney, so that he or she can assess your case in the manner that a USCIS officer would process it.