Alien Identification Number: Where to Find It and How to Retrieve It

An Alien Registration Number, usually shortened to A-Number, is the unique seven-, eight-, or nine-digit identifier the Department of Homeland Security assigns to track your immigration history in the United States.¹ Once assigned, it stays with you for life. Every application you file, every notice you receive, and every record the government keeps about your case is indexed to that single number.

Where to Find Your A-Number

Your A-Number appears on the immigration documents the government has already issued you. If you hold more than one of these, the number should match across all of them.

Permanent Resident Card (Form I-551). On green cards issued after May 2010, the number is labeled “USCIS#” rather than “A-Number,” but it is the same number. Older cards show it as “A-Number” or “Alien Registration Number.”²³
Employment Authorization Document (Form I-766). The number appears on the front of the work permit, also labeled “USCIS#” on current versions.
Immigrant Data Summary. This sheet is stapled to the front of the visa package handed to you after an interview at a U.S. embassy or consulate. The A-Number sits at the top.⁴
Immigrant visa foil in your passport. The consulate lists it as the “Registration Number.”⁴
Notice of Action (Form I-797). When USCIS receives or approves a petition, the notice typically includes your A-Number if one has been assigned.

If you never received an Immigrant Data Summary or misplaced your visa packet, USCIS advises contacting the embassy or consulate that issued the visa to request a copy.⁴

A-Number vs. USCIS Receipt Number

These are not the same thing, and the “USCIS#” label on newer cards makes the confusion worse. Your A-Number belongs to you as a person and follows you permanently across every application you ever file. A receipt number belongs to a single application or petition. It is a 13-character code beginning with three letters that identify the processing center (such as “EAC” or “IOE”), followed by 10 digits.⁵

The distinction matters when you check case status online. The USCIS case tracker only accepts the 13-character receipt number, not your A-Number.⁵ Your receipt number appears on every Form I-797 Notice of Action. If you have multiple pending applications, each has its own receipt number, but all of them link back to your single A-Number in the USCIS system.

How to Retrieve a Lost A-Number

If none of your documents show the number, you can retrieve it by requesting your own immigration records through a Freedom of Information Act or Privacy Act request. As of January 22, 2026, USCIS requires these requests to be submitted online through the FIRST portal at first.uscis.gov. Online submission is the only accepted method.⁶

You will need a USCIS online account and enough identifying information for the agency to locate your file: your full legal name as it appears on government records, any aliases you have used, your date of birth, and your country of birth. More detail speeds the process. Leaving information out will not disqualify a request, but USCIS warns it may need extra time or may not be able to find your records at all.⁷

Once submitted, you can track the request, receive notifications, and download your records through your USCIS account.⁸ Processing times depend on the current backlog. One caution worth taking seriously: providing false information on a federal records request is a federal crime carrying fines or up to five years in prison.⁹

If an attorney or accredited representative has filed a Form G-28 for you, they can request your records through their own USCIS account.⁶ Anyone else asking on your behalf generally needs your written, signed, and notarized consent.¹⁰

Who Has an A-Number and Who Doesn’t

Not every non-citizen in the United States has one. The number is reserved for people who have taken a step into what immigration agencies treat as the long-term or permanent-status pipeline, or who have come to the government’s attention through enforcement. Federal regulations list the specific forms that trigger registration.¹¹ The most common categories are:

Anyone filing Form I-485 to adjust status to lawful permanent resident. The number issued at that point stays with the person for life.¹¹
Recipients of an Employment Authorization Document (Form I-766), including students on Optional Practical Training and DACA recipients.¹²
Anyone served with a Notice to Appear or referred to an immigration judge.¹¹

Short-term visitors on tourist or business visas generally do not receive an A-Number. Neither do most holders of temporary non-immigrant work visas such as the H-1B, unless they take a concrete step toward permanent residency (for example, their employer files a Form I-140 immigrant petition, or they file an adjustment-of-status application). Some non-immigrant visa holders already have an A-Number from an earlier interaction with the system, such as a prior asylum application or a Diversity Visa lottery entry. If you have never applied for anything in these categories, you likely do not have an A-Number at all.

The Re-Registration Requirement at Age 14

Children under 14 are not exempt from registration, and parents or legal guardians are responsible for making sure it happens.¹³ In practice, registration happens automatically when a parent includes the child on an immigrant petition or adjustment application.

The deadline that catches families off guard comes later. Within 30 days of turning 14, any previously registered non-citizen in the United States must apply for re-registration and be fingerprinted.¹³ For lawful permanent residents, applying for a new green card usually satisfies the requirement. If the child is outside the country on their 14th birthday, the 30-day clock starts when they return.¹¹ Missing the deadline does not erase the child’s A-Number, but it creates a compliance gap that can complicate later applications.

1
U.S. Citizenship and Immigration Services. A-Number/Alien Registration Number/Alien Number
2
U.S. Citizenship and Immigration Services. USCIS Number
3
U.S. Citizenship and Immigration Services. 13.1 List A Documents That Establish Identity and Employment Authorization
4
U.S. Citizenship and Immigration Services. Immigrant Fee Payment – Tips on Finding Your A-Number and DOS Case ID
5
U.S. Citizenship and Immigration Services. Checking Your Case Status Online
6
U.S. Citizenship and Immigration Services. Request Records through the Freedom of Information Act or Privacy Act
7
U.S. Citizenship and Immigration Services. Form G-639
8
U.S. Citizenship and Immigration Services. USCIS Expands FIRST – A Fully Digital FOIA System
9
Office of the Law Revision Counsel. 18 U.S. Code 1001 – Statements or Entries Generally
10
U.S. Citizenship and Immigration Services. Chapter 7 – Privacy and Confidentiality
11
eCFR. 8 CFR 264.1 – Registration and Fingerprinting
12
U.S. Citizenship and Immigration Services. Employment Authorization Document
13
U.S. Citizenship and Immigration Services. Alien Registration Requirement