If you commit such an act, you may be brought before an immigration court to determine your right to remain a permanent resident.
Abandoning Permanent Resident Status
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
Tax Return
Fail to file income tax returns while living outside of the United States for any period
Carry It With You At All Times
Change of Address
Notify USCIS within 10 days of changing your address
Green Card Renewal
Green cards expire after 10 years (the card, not the status) and should be renewed preferably within 6 months of the time they are to expire and certainly even after they expire
Social Security Card
Carry it with you when you travel outside the US
International Travel
0-6 months
No problem
Can be in single or multiples shorter trips
6 months - 1 year
You apply for reentry to the officer at the point of entry by presenting your green card
1 - 2 years
You need a re-entry permit
>2 years