Alien Definition
The Boundless Immigration Glossary
WHAT IS AN ALIEN?
Nonresident Alien
Nonresident alien is a term used by the Internal Revenue Service to describe anyone who is neither a U.S. citizen nor a green card holder, and who is not “substantially present” in the United States. Many students and other nonimmigrants who spend significant time in the United States are, for tax purposes, nonresident aliens when they first arrive, but soon become resident aliens.
Resident Alien
A resident alien is any non-U.S. citizen who resides in the United States. The term includes green card holders, but for tax purposes many other non-citizens are considered resident aliens.
Legal Aliens
A legal alien is a noncitizen who has been granted permission to reside in the United States under a specific immigration status. This individual holds documentation proving their lawful presence, such as a visa, green card (permanent resident card), or work authorization, allowing them to live, work, study, or travel in the U.S. within the conditions of their status.
Legal aliens include various groups, such as:
Asylees and Refugees: Individuals granted protection due to persecution who have been allowed to stay in the U.S.
Nonimmigrants: Temporary visitors, such as tourists, students, or workers, who are in the U.S. under a visa with specific terms and durations.
Lawful Permanent Residents (LPRs): Also known as green card holders, who have the right to live and work in the U.S. indefinitely.
Illegal Aliens
An illegal alien is a term historically used in U.S. immigration law to describe a noncitizen who is present in the United States without legal authorization. This includes individuals who entered the U.S. without inspection at a port of entry or those who entered lawfully but overstayed their visa or violated the terms of their legal status.
Important:
The term “illegal alien” is largely considered outdated and has been replaced in many contexts by terms like undocumented immigrant or unauthorized immigrant to more accurately and respectfully describe individuals without legal immigration status.