You may be found to have abandoned your permanent resident status if you:

• Move to another country intending to live there permanently
• Remain outside of the United States for more than 1 year without obtaining a reentry permit or returning resident visa. However, in determining whether your status has been abandoned, any length of absence from the United States may be considered, even if less than 1 year
• Remain outside of the United States for more than 2 years after issuance of a reentry permit without obtaining a returning resident visa. However, in determining whether your status has been abandoned any length of absence from the United States may be considered, even if less than 1 year
• Fail to file income tax returns while living outside of the United States for any period
• Declare yourself a “nonimmigrant” on your tax returns

The green card holder who returns to the U.S. after a temporary departure is not seeking new admission unless he:

• Has abandoned or relinquished legal permanent residence status
• Has been absent from the US for a continuous period of over 180 days
• Has engaged in illegal activity after departing the US
• Departs during removal proceedings
• Committed an offense making him inadmissible under 212(a)
• Is attempting to enter at a place other than a point of entry; or
• Has entered without inspection. INA 101(a)(13)(C).