Lawful permanent residents can only lose their green cards in two ways:
· An Immigration Judge takes it away after an abandonment hearing, or
· You voluntarily give it up by signing a form I-407.
In the aftermath of the travel ban in the 1/26/2017 executive order, the American Immigration Lawyers Association has issued a practice alert that the Customs and Border Protection (CBP) officials have pressured lawful permanent residents - sometimes while still on the plane - to give up their residence by signing form I-407. Lawful permanent residents, including those from the listed countries (Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen), should NOT sign this form. There is no penalty for refusing to sign, and the CBP cannot detain you because of your refusal.
If you are lawful permanent resident and have been away from the United States for an extended period of time, CBP may question whether you have abandoned your residence. If that happens, be prepared to show your ties to the United States and the temporary reason for your extended stay overseas.
If the officer charges abandonment, you have a right to a hearing, and you will be issued a Notice to Appear in Immigration Court on a specified date. You also cannot be detained for insisting on your right to an immigration court hearing. If your card is confiscated pending your hearing date, you have a right to temporary proof of your permanent residency.