If you have a permanent resident card valid for 10 years that has expired or will expire in the next 6 months, you will need to renew your Green Card.
How To Renew a Green Card if You Are Outside the United States
If you are outside the United States and your Green Card will expire in the next 6 months (but you will return within 1 year of your departure from the United States and before the card expires), you must apply renew your card as soon as you return to the United States.
If you are outside the United States when your card expires and you have not requested the renewal of the card before your departure, you should contact the nearest United States Consulate, with the USCIS office (Citizenship and Immigration Services United States), or with the port of entry into the United States before attempting to file Form I-90 for Green Card renewal.
You must submit Form I-90, Application to Replace Permanent Resident Card along with the supporting documentation necessary to establish your identity and that you are still a lawful permanent resident.
After your case is officially presented, a biometrics appointment will be scheduled for you. The biometric data appointment consists of the electronic capture of photograph, signature, index fingerprint and ten impression fingerprints of an applicant. The “biometrics” are used to generate your new legal permanent card and carry out a criminal background check.