The Application of Reentry Permit to Avoid Abandoning the Green Card

Question:

I recently received my Green Card, and I am planning to travel outside of United States for more than one year due to my work and family reason. How to keep my Green Card in the United States? and I can come back later without any problem to enter United States?

Answer:

A Green Card holder (U.S. lawful permanent or conditional resident) can travel outside the U.S. and return, with some limitations. A reentry permit can help prevent two types of problems: 1) your Green Card becomes technically invalid for reentry into U.S., if you are absent from U.S. for one year or more;  2) your Green Card status may be considered as abandoned for absences shorter than one year, if you take up residence in another country.
 
A reentry permit establishes that a Green Card holder did not intend to abandon U.S. permanent residence status, and it allows you to apply for admission to U.S. after traveling abroad for up to 2 years without having to obtain a returning resident visa. If you are a Green Card holder planning to travel outside of U.S. for one year or more, it is important that you apply for a reentry permit

A reentry permit is used when a U.S. Green Card holder wishes to leave the United States for a period of between 1 year and 2 years, but does not want to be viewed as having abandoned the U.S. residence or Green Card. The USCIS Form I-131 is used to apply for a Reentry Permit.
 
As a Green Card holder, you must be in United States when applying for a reentry permit, and must attend the USCIS biometrics appointment before leaving United States. But you can request to pick up the reentry permit approval at a U.S. embassy in your home country, or you can ask that it be sent to an overseas address. The reentry permit itself looks similar to a passport, and will contain your photo. It will normally expire after 2 years.
 
http://www.greencardapply.com/question/question15/I131_Reentry_Permit_122115.htm
http://www.greencardfamily.com/question/question2015/Reentry_Permit_Application_121415.htm