Permanent residence (United States)

A United States Permanent Resident Card, also known as a green card is an Identification card attesting to the permanent resident status of an alien in the United States of America. Green card also refers to an immigration process of becoming a permanent resident. The green card serves as proof that its holder, a Lawful Permanent Resident (LPR), has been officially granted immigration benefits, which include permission to reside and take employment in the USA. The holder must maintain permanent resident status, and can be removed from the US if certain conditions of this status are not met.

The card must be in the possession of the U.S. permanent resident at all times. This means that the permanent resident must have a currently valid card on the person at all times and be able to show it to a USCIS officer, if requested. Though aliens with permanent resident status are required to carry these identification cards, american citizens are not required to carry any citizenship identification. Before the September 11, 2001 attacks.

A Lawful Permanent Resident can apply for United States citizenship , or naturalization, after five years of residency. This period is shortened to three years if married to a U.S. citizen, or four years if permanent residency was received throughpolitical asylum.

Sources: http://en.wikipedia.org/wiki/United_States_Permanent_Resident_Card
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