:: Re-entry Permit
The Re-entry Permit allows Lawful Perminent Residents(LPR) to travel abroad for more than one year without losing LPR status.

:: What is the validity period of Re-entry Permit?
Generally, a Re-entry Permit is valid for two years from the date of issuance. However, if the LPR has been outside the U.S. for more than 4 of the last 5 years, the permit will be limited to 1 year.

:: Filing the application in the U.S.
LPRs must be physically present in the U.S. when filing the application. However, LPRs may receive the Re-Entry Permit abroad.

:: Abroad for over one year without Re-entry Permits
LPRs must obtain a Special Immigrant Visa before returning to the U.S. In order to determine that an LPR has not abandoned his/her resident status, the U.S. embassy will take into consideration many factors.