The US green card can make the green card holder a permanent resident of the US for life. In most cases, this status is truly permanent, but in some very rare cases the green card can be revoked. This usually happens due to:
While it is quite difficult to lose permanent residency status, it is possible to have your green card lapse. This is because while permanent resident status is permanent, your US green card is not. The government asks that all green card holders take part in green card renewal as needed. This helps the US government fight fraud and allows the government to issue new green cards with new security features.
In most cases, US green cards are valid for ten years. Conditional green cards are usually valid for two. If your green card will expire in six months or less, you will want to go through the green card renewal process to ensure that you get your new green card in time. You can simply visit the USCIS website to fill out a green card renewal application. If you need it, you will get temporary documentation to prove that you are a permanent resident. You can use this documentation until your new green card arrives.