When a non-citizen is a lawful permanent resident (LPR), they are usually allowed to leave the U.S. and return almost as easily as a citizen. There are certain circumstances when LPRs who are returning to the U.S. will be treated like other non-citizens. Those situations include when the LPR has a criminal conviction that makes them inadmissible, they left the U.S. to engage in criminal activity and when they are outside of the U.S. for more than one year.
In that third situation, often times the CBP officer at the airport will ask you why you were outside of the U.S. for so long and sometimes try to convince you to sign a Form I-407 Abandonment of Lawful Permanent Resident Status. DON’T DO IT! It is the government’s burden to prove that you abandoned your LPR status, by signing the form, you are admitting they are correct and you will likely lose your green card. There is much more analysis involved in whether you abandoned your green card then just being outside of the U.S. for more than a year.
If you find yourself in that situation, don’t sign the I-407, tell the officers you want to keep your green card and see an Immigration Judge. They will likely send you to Deferred Inspection, issue you a Form I-862 Notice to Appear and then send you to see an Immigration Judge. Even though CBP may have taken your actual green card, you are still a lawful permanent resident until an Immigration Judge issues a final order of your removal from the United States.