Generally, a U.S. permanent resident may not leave the U.S. for more than one year at a time. Doing so triggers the presumption that he or she has abandoned his or her permanent residence in the U.S.

A permanent resident who needs to stay outside the U.S. for more than one year and who does not want to be considered as having abandoned his or her green card may file an application for a reentry permit. This document allows a permanent resident to remain outside the U.S. for more than one year without being presumed to have abandoned his or her green card. The applicant must file Form I-131 with the U.S. Citizenship & Immigration Services (USCIS) while physically present in the U.S. There is also a biometrics requirement for applicants between the ages of 14 and 79. Applicants must be in the U.S. to have their biometrics taken. USCIS has stated that it may deny reentry permit applications for those applicants who leave the U.S. after submitting their applications but prior to receiving their biometrics. If a permanent resident remains outside the U.S. for the duration of the reentry permit, that time spent outside the U.S. does not count toward the required period of continuous residence for U.S. citizenship (five years or three years if married to a U.S. citizen). The maximum initial duration of a reentry permit is two years. Reentry permits may be extended in two year increments for a maximum duration of six years, however the applicant must provide USCIS with a reason for the request for the reentry permit. In addition, the applicant must continue to maintain ties to the U.S. during the time spent abroad.