Definition
Alien Registration Number
Also: A-Number
A unique 7-, 8-, or 9-digit number assigned by USCIS to identify a noncitizen.
The A-number (sometimes called an "Alien Number" or "USCIS#") is printed on green cards, EAD cards, and most USCIS notices. It identifies the noncitizen across all DHS systems.
See also
Not legal advice. Definitions are provided for educational use. For case-specific guidance, consult a licensed immigration attorney.