How to become Permanent Resident of the United States

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United States lawful permanent residency refers to a person's immigration status: the person is authorized to live and work in the United States of America on a permanent basis.

A United States Permanent Resident Card (USCIS Form I-551), formerly Alien Registration Card or Alien Registration Receipt Card (INS Form I-151), is an identification card attesting to the permanent resident status of an alien in the United States. It is known informally as a green card because it had been green in color from 1946 till 1964, and it has reverted to that color since May 2010.
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 United States if certain conditions of this status are not met.

Green cards were formerly issued by the Immigration and Naturalization Service (INS). During a re-organization process, that agency was absorbed into and replaced by the Bureau of Citizenship and Immigration Services (BCIS), part of the Department of Homeland Security (DHS). Shortly after that re-organization, BCIS was renamed to U.S. Citizenship and Immigration Services (USCIS), which still retains the responsibility for issuing green cards.

Permanent residents of the United States eighteen years of age or older must carry their valid physical green card itself at all times