Green Card Number: How to find it?

TL;DR

• A Permanent Resident Card has two key identifying numbers, not one. Most people searching for their "green card number" are looking for one of these two, and the distinction matters.

• The Document Number (also called the card number or green card number) is a 13-character alphanumeric code printed in the machine-readable zone on the back of the card. It identifies the specific physical card.

• The USCIS Number (also called the A-Number or Alien Registration Number) is a 7 to 9-digit number labeled "USCIS#" on the front of the card. It identifies you as an individual and stays with you permanently, even across multiple card replacements.

• These two numbers serve different purposes and go in different fields on Form I-9. Confusing them is one of the most common I-9 errors.

What Is the Green Card Number?

The term "green card number" is used loosely and can refer to either of two distinct numbers printed on a Permanent Resident Card (Form I-551). Understanding which number is being requested in any given context is essential.

The Document Number is the number most commonly called the "green card number." It is a 13-character alphanumeric code beginning with three uppercase letters followed by ten digits, for example LIN1234567890. The three-letter prefix refers to the USCIS service center that processed the card (such as LIN for Lincoln, EAC for Eastern Adjudication Center, or WAC for Western Adjudication Center). This number identifies the specific physical card. It changes every time a new card is issued, whether for renewal, replacement after loss, or a name change.

The USCIS Number (also called the A-Number or Alien Registration Number) is a 7 to 9-digit number, always preceded by the letter "A," for example A012345678. Per the USCIS glossary, this number is assigned to you personally by the Department of Homeland Security and stays with you for life regardless of how many times your card is replaced or renewed. It is the number USCIS uses to track your immigration history across all forms and petitions you ever file.

Both numbers appear on every green card issued after May 10, 2010. They are different numbers with different purposes, located in different places on the card.

Where Is Each Number Located on the Card?

Front of the Card (USCIS Number)

The front of a current Permanent Resident Card (issued after May 2010) displays the cardholder's photograph, full name, date of birth, country of birth, and the number labeled "USCIS#". That "USCIS#" label refers to the A-Number: a 7 to 9-digit personal identifier.

This is confirmed directly by the USCIS glossary, which defines the USCIS Number as "a unique, 9-digit number assigned to an alien by the Department of Homeland Security that is listed on the front of Permanent Resident Cards issued after May 10, 2010."

On older green cards issued between 2004 and 2010, the same number appeared under the label "A#" rather than "USCIS#."

Back of the Card (Document/Green Card Number)

The back of the card contains the machine-readable zone (MRZ), a section of text formatted for automated document scanning. Embedded within the MRZ is the Document Number: the 13-character alphanumeric code (three letters followed by ten digits) that identifies this specific physical card. This is the number most commonly referred to as the "green card number" when a form asks for a card number or document number.

Green Card Number vs USCIS Number: Key Differences

People frequently confuse these two numbers, particularly when completing Form I-9. The table below summarizes what each one is, where it lives, and what it is used for.

The core distinction:

• The A-Number identifies you

• The Document Number identifies the card in your wallet right now.

What Is the USCIS Number on a Green Card?

When a green card says "USCIS#" on the front, it is referring to your Alien Registration Number (A-Number). These three terms refer to the same thing:

• USCIS Number

• USCIS#

• A-Number

The only formatting difference is that the A-Number includes the "A" prefix (A012345678) while the USCIS Number drops the prefix (012345678). Both refer to the same identifier.

This is a common source of confusion because "USCIS number" sounds like it could refer to a case number or the 13-character Document Number. It does not. When you see "USCIS#" on the front of your green card, you are looking at your personal Alien Registration Number.

When Do You Need Each Number?

The Document Number (13 characters, back of card)

The Document Number is what employers and certain agencies use when they need to reference the specific card you presented. Its most common use is Form I-9 (Employment Eligibility Verification). In Section 2 of Form I-9, the employer records information from the documents the employee presents.

When a green card is presented, the employer enters the Document Number in the "Document Number" field. It is also used in E-Verify when matching a specific card.

The A-Number / USCIS Number (7 to 9 digits, front of card)

The A-Number is the number used across virtually all USCIS forms and immigration proceedings. You will be asked for it on renewal applications, naturalization applications, adjustment of status forms, and most other petitions you file with USCIS throughout your life as a permanent resident and beyond.

In Section 1 of Form I-9, the employee (not the employer) enters their A-Number or USCIS Number when attesting to their status as a lawful permanent resident.

What to Do If You Cannot Find Your Green Card Number

If you are looking for the Document Number (13-character card number) and cannot locate it, first check the back of your card in the machine-readable zone. If your card is damaged, expired, or you are working from memory, you may be able to locate it on any previous USCIS correspondence related to your original card issuance.

If you need your A-Number and cannot find it, check the front of your green card (labeled "USCIS#"), any Notice of Action (Form I-797) USCIS has sent you, your Employment Authorization Document (EAD) if you have one, or your immigrant visa if you went through consular processing.

If your green card is lost or stolen, you cannot retrieve a new card number without replacing the card. File Form I-90 (Application to Replace Permanent Resident Card) with USCIS to obtain a replacement. The replacement card will have a new Document Number, though your A-Number will remain the same.

As a practical habit, keep a photocopy of both the front and back of your green card in a secure location separate from the card itself. This makes both numbers available in any situation where the physical card is unavailable.

Frequently Asked Questions

What is the green card number?

The term "green card number" most commonly refers to the 13-character Document Number printed in the machine-readable zone on the back of the Permanent Resident Card.

It begins with three uppercase letters followed by ten digits (for example, LIN1234567890) and identifies the specific physical card. It is separate from the A-Number, which identifies the cardholder personally and appears on the front of the card labeled "USCIS#."

Where is the green card number on the card?

The Document Number (the 13-character card number) is on the back of the card, in the machine-readable zone. The USCIS Number / A-Number is on the front, labeled "USCIS#."

On cards issued before May 2010, the labeling and layout may differ slightly. If in doubt, the 13-character code is always the Document Number; the 7 to 9-digit number is always the A-Number.

Is the green card number the same as the A-Number?

No. These are two distinct numbers. The A-Number (also called the USCIS Number or Alien Registration Number) is a 7 to 9-digit number assigned to you personally, labeled "USCIS#" on the front of the card.

The green card number (Document Number) is a 13-character alphanumeric code on the back of the card that identifies the specific physical card. The A-Number stays the same across all your immigration documents; the Document Number changes each time a new card is issued.

What is the USCIS number on a green card?

The "USCIS#" label on the front of a Permanent Resident Card refers to your Alien Registration Number (A-Number). Per the USCIS glossary, this is a unique 7 to 9-digit number assigned to you by the Department of Homeland Security.

It is your permanent personal identifier in the U.S. immigration system and appears on most immigration documents you will ever receive.

What is the green card number used for?

The Document Number (13-character card number) is used when a form or system requires identification of the specific physical card you hold. Its most common use is in Section 2 of Form I-9, where an employer records it when verifying work authorization.

The A-Number is used far more frequently, appearing on virtually all USCIS application forms, immigration court documents, and benefit applications.

How many characters is a green card number?

The Document Number (commonly called the green card number or card number) is 13 characters: three uppercase letters followed by ten digits. The A-Number, which is a different identifier on the same card, is 7 to 9 digits preceded by the letter "A."

What do I do if I lost my green card and need the number?

If your physical card is lost or stolen, file Form I-90 (Application to Replace Permanent Resident Card) with USCIS to obtain a replacement.

You may be able to retrieve your A-Number from prior USCIS correspondence, approval notices (Form I-797), or any other immigration documents in your records.

The Document Number is card-specific and changes with each new card, so a new number will be issued when the replacement card is produced.

This article is intended for general informational purposes only and does not constitute legal advice. For guidance specific to your situation, consult a licensed immigration attorney.