Documents Required on Reentry

• You need a valid green card --- Form I-551 or permanent resident card --- when you arrive at the port of entry from a trip abroad. A U.S. Customs and Border Protection Officer will review your permanent resident card and other identity documents you present such as your passport, foreign national identity card or a U.S. driver's license before determining whether you are in good standing to reenter the country or not.
  
  

Brief International Trips

• A brief travel overseas generally does not affect your permanent resident status. But you risk jeopardizing your stay in the U.S. as a permanent resident if you leave the country for an extended period. For instance, you could be found to have abandoned your permanent resident status if you stay abroad for an extended period of up to a year. Absences of six months or more, according to the U.S. Citizenship and Immigration Services (USCIS), may disrupt the continuous residency required for naturalization.
  
  

United States Ties

• While a brief visit abroad is not usually a problem, the U.S. Customs and Border Protection officer at the port of entry will consider criteria such as whether your intention to travel was only temporarily by looking at your U.S. ongoing ties. Factors considered include family and community ties, employment and filed taxes as a resident. The officer also looks into whether you have maintained a U.S. mailing address, a bank account and a valid driver's license. Owning property or business is also helpful when establishing your U.S. ties, or any evidence that can support the temporary nature of your absence.
  
  

Trips Longer Than One Year

• If you intend to be absent from the country for a period exceeding a year, it is important to apply for a reentry permit on Form I-131 before departure, according to USCIS. The permit allows reentry during the period it is still valid without the need to obtain a returning resident visa from a U.S. embassy or consulate abroad. It is, however, worth noting that a reentry permit does not guarantee admission into the U.S. upon your return. You have to prove your intentions to continuing living in the U.S. as a permanent resident. You can also file an Application to Preserve Residence for Naturalization Purposes on Form N-470 if you want to stay abroad for more than two years and you wish to preserve your continuous residency.