While Permanent Resident status itself does not expire, Green Cards (the official documentation of Permanent Resident status) must be renewed every 10 years. Neglecting to renew your Green Card may make it difficult to travel internationally or to prove your eligibility for employment in the U.S.
Permanent Residents renew their Green Cards every 10 years by using the Form I-90, Application to Replace Permanent Resident Card. Form I-90 can also be used to replace a non-expired Green Card.
In addition to renewals, Form I-90 can also be used to replace a current Green Card in the following situations:
Conditional Permanent Residents are given a Green Card that is only valid for two years. Form I-90 should NOT be used to renew a Conditional Permanent Resident status.
Within 90 days of the two-year expiration date, Conditional Permanent Residents are required to file a petition to "remove the conditions" from their Green Card. If your conditional status was based on a marriage, you must file Form I-751, Petition to Remove Conditions on Residence. If your conditional status was based on being an investor, you must file Form I-829, Petition by Entrepreneur to Remove Conditions on Permanent Resident Status.
Once your petition is approved, you will receive a new Green Card, valid for 10 years. After that point, the typical renewal process (including Form I-90) should be used.
Applications for Green Card renewal may be denied for various reasons. Two of the most common reasons would be criminal activity and adjustment of immigrant category.
Criminal activity means that you committed a crime and are therefore no longer seen as a valuable asset to American society. However, this is really only applicable to major crimes such as felonies. Minor crimes such as speeding tickets would probably not result in a denial of a Green Card renewal application.
Adjustment of immigrant category means that your circumstance has changed in such a way that the reason you were granted a green card is no longer applicable. For example, if you were granted a Green Card through marriage to a US citizen but have since gotten divorced, your application for a Green Card may be denied.
If your Green Card renewal application was denied, you do have an opportunity to ask USCIS to rethink their decision. You may submit a motion to reopen or a motion to reconsider with the same office that denied your application. This will cause USCIS to reexamine your case and reconsider their decision.
In the motion to reopen, be sure to clearly state and provide evidence for why your application was wrongly denied and why USCIS should reconsider.
All modern U.S. immigration law is filed under the Immigration and Nationality Act (INA). Section 264 of the INA is about Green Cards. It reads as such:
"Every alien in the United States . . . shall be issued a certificate of alien registration or an alien registration receipt card in such form and manner and at such time as shall be prescribed under regulations . . .."
This means that every U.S. immigrant shall be granted a Green Card. The INA also reads:
"Every alien, eighteen years of age and over, shall at all times carry with him and have in his personal possession any certificate of alien registration or alien registration receipt card issued to him . . .. Any alien who fails to comply with [these provisions] shall be guilty of a misdemeanor ..."
This means that if you are an immigrant, you must always carry your Green Card with you.