Green Card Number Explained: Where to Find It

Your green card (Form I-551, Permanent Resident Card) carries multiple numbers that each serve a distinct purpose in the U.S. immigration system. The green card number is a unique 13-character identifier assigned to the physical card itself, made up of three letters followed by ten digits. It is not the same as the Alien Registration Number (A-Number) printed on the card's front or the Social Security Number. This guide breaks down every number on the green card, where each one is located, when employees and employers need each number, and how to recognize common errors that cause processing delays or I-9 compliance penalties.

What Is a Green Card Number?

The green card number is a unique 13-character code printed on every Permanent Resident Card (Form I-551) issued by USCIS. It functions as a document-level identifier, meaning it tracks the specific physical card rather than the person holding it. If a card is renewed, replaced, or reissued through Form I-90, a new green card number is assigned. The underlying immigration record stays linked to the permanent A-Number.

This code may also be referred to as the "card number" or "document number." Every USCIS filing generates a "receipt number" in the same 13-character format, but the code printed on an issued I-551 specifically identifies the case that produced that card. On Form I-9 and in most employer-facing contexts, the term "document number" is the standard label for this 13-character code.

How the Green Card Number Is Structured

Each segment of the 13-character code encodes specific case information:

• First three letters (service center code): Identifies the USCIS facility that processed the case. Common codes include MSC and NBC (both refer to the National Benefits Center), EAC (Vermont Service Center), WAC (California Service Center), LIN (Nebraska Service Center), SRC (Texas Service Center), IOE (online/electronic filing), and YSC (Potomac Service Center)
• Next two digits (fiscal year): The federal fiscal year in which USCIS received the case. The fiscal year runs October 1 through September 30, so "26" refers to FY2026 (October 1, 2025 through September 30, 2026)
• Next three digits (workday): The specific computer workday within that fiscal year on which USCIS processed the fee and generated the receipt
• Final five digits (case number): A unique case identifier within that service center, fiscal year, and workday combination

Example: A green card number starting with MSC2612350001 indicates the case was processed at the National Benefits Center, received during Fiscal Year 2026, on workday 123, as case number 50001.

Green Card Number vs. A-Number vs. Social Security Number

Confusing these numbers is one of the most frequent errors employees and employers make. Here is how they differ:

Green card number (document number): 13 characters (3 letters + 10 digits). Identifies the physical card. Changes with every renewal or replacement. Located on the back of cards issued after May 2010. Required as the "Document Number" on Form I-9 Section 2.

A-Number (USCIS#): 7 to 9 digits, preceded by the letter "A." Identifies the individual in the immigration system. Never changes across card renewals, EAD issuances, or naturalization. Located on the front of the card, labeled "USCIS#" (older cards may display "Alien #" or "A#"). Required on USCIS forms such as I-90, I-485, and N-400.

Social Security Number (SSN): 9 digits issued by the Social Security Administration. Used for tax reporting, employment records, and federal benefits. Does not appear anywhere on the green card and is not interchangeable with the green card number or A-Number on immigration forms.

The "USCIS#" label on the front of the card is a common source of confusion because many people assume it refers to the green card number. It does not. It refers to the A-Number. When a form asks for "USCIS number" or "A-Number," the number from the front applies. When it asks for "card number" or "document number," the 13-character code from the back applies.

Where to Find the Green Card Number on Your Card

The physical location depends on when the card was issued. USCIS has redesigned the Permanent Resident Card multiple times, shifting where key fields appear. The USCIS Handbook for Employers (M-274), Section 13.1 documents each card version and its acceptability for Form I-9.

Current Design (Issued After January 30, 2023)

USCIS began issuing the current card design on January 30, 2023, featuring updated artwork, enhanced holographic images on both sides, and a new layer-reveal security feature.

Front of card: Displays the cardholder's photo, name, date of birth, USCIS# (the A-Number), category of admission, "Resident Since" date, and card expiration date. The green card number does not appear on the front.

Back of card: Contains three lines of machine-readable text (90 characters total). The green card number is embedded in the first line at character positions 16 through 28, followed by two filler symbols. The 13-character code starts with the three-letter service center prefix followed by ten digits.

Cards Issued May 2010 Through January 2023

These cards introduced the green color scheme. The green card number sits on the back in the machine-readable zone, in the same position as the current design. The front displays the A-Number under "USCIS#." Cards issued after the May 2017 mid-cycle redesign removed the bearer's signature and added photos on both sides, but the green card number location remained on the back.

Cards Issued Before May 2010

On older versions, the green card number may appear on the front of the card rather than the back. The labeling may read "Card#" or reference "I-551." Some older cards have no printed expiration date and remain technically valid, but USCIS has noted that cardholders may file Form I-90 to obtain a current card.

Reading the Machine-Readable Zone

The three lines on the back of modern cards follow the ICAO TD1 format (three lines of 30 characters each), though USCIS uses a non-standard document-type field in the first two character positions:

Line 1 (30 characters):

• Positions 1-2: "C1" (U.S. permanent resident) or "C2" (permanent resident commuter from Canada or Mexico)
• Positions 3-5: "USA"
• Positions 6-14: A-Number (zero-padded to 9 digits)
• Position 15: Check digit
• Positions 16-28: Green card number (13 characters)
• Positions 29-30: Filler characters

Lines 2 and 3 encode the date of birth, sex, card expiration date, country of birth, and name in a standardized format.

When You Need Your Green Card Number

Form I-9 Employment Verification

The green card is a List A document that establishes both identity and employment authorization. Per the USCIS Handbook for Employers (M-274), Section 13.1, when completing Section 2 of Form I-9, the employer records:

• Document Title: "U.S. Permanent Resident Card" or "Form I-551"
• Issuing Authority: "USCIS" or "U.S. Citizenship and Immigration Services"
• Document Number: The 13-character green card number from the back of the card
• Expiration Date: The "Card Expires" date from the front

A common I-9 mistake is entering the A-Number from the front instead of the 13-character green card number from the back. An A-Number is 7 to 9 digits; the document number is a 13-character alphanumeric code. Auditors can spot this error instantly, and patterns of this mistake across employee files can result in penalties during an ICE inspection.

Green Card Renewal or Replacement (Form I-90)

When filing Form I-90, the applicant provides the green card number from the current or most recent card, plus the A-Number, class of admission code, and "Resident Since" date. Filing fees are $415 online or $465 by mail (as of the USCIS Fee Schedule (Form G-1055), edition 05/06/26, per 8 CFR 106.2(a)(1) and 8 CFR 106.1(g) online filing discount). No separate biometrics fee is required; biometric services costs are bundled into the form filing fee under the fee rule effective April 1, 2024 (89 FR 6386). Note: The DHS Interim Final Rule published April 29, 2026 (91 FR 22952, effective May 29, 2026), which codifies new H.R.1 fees for certain other forms, does not modify Form I-90 fees.

USCIS Form I-90 instructions state that the agency will not accept a renewal application unless the card will expire within six months. This is a regulatory filing cutoff, not a soft recommendation.

As of September 10, 2024, USCIS provides a 36-month automatic extension of card validity for permanent residents who file Form I-90 to renew an expiring or expired green card. The 36 months are measured from the card's printed expiration date. The receipt notice (Form I-797C), presented alongside the expired card, serves as proof of continued status and employment authorization while the renewal processes. This policy replaced a previous 24-month extension. This extension applies to renewal filings where the cardholder still possesses the expired card. For lost or stolen cards, the cardholder may request an Alien Documentation, Identification, and Telecommunications (ADIT) stamp at a USCIS field office for temporary proof of status.

Other Common Situations Requiring the Green Card Number

• Naturalization (Form N-400): Asks for the A-Number and green card number. Accurate entry helps avoid processing delays.
• International travel: Airlines and customs officials may request the number when verifying permanent resident status.
• Reentry permits (Form I-131): Requires card and immigration status details.
• Background checks and security clearances: Some applications reference the document number for identity verification.

What the Category Code on Your Green Card Means

The "Category" field on the front of the card shows the immigrant visa classification under which the cardholder was admitted. This code, also called the "class of admission," typically consists of one or two letters followed by a number. This code is needed when filing Form I-90 or Form I-131.

Common employment-based codes include E11 (EB-1A Extraordinary Ability), E12 (EB-1B Outstanding Professor/Researcher), E13 (EB-1C Multinational Manager/Executive), E21 (EB-2 NIW), and codes for EB-2 PERM and EB-3 categories. Note: Codes E11 through E15 are assigned to immigrant-visa entrants (consular processing). Cards showing E16, E17, or E18 represent the same EB-1A, EB-1B, and EB-1C categories, respectively, for individuals who adjusted status inside the United States. The full list of class of admission codes is available through the DHS Office of Homeland Security Statistics and the State Department's Immigrant Visa Symbols reference.

What to Do If You Cannot Find Your Green Card Number

If Your Card Is Lost, Stolen, or Damaged

Filing Form I-90 with USCIS initiates a replacement. The green card number is not required to file. The A-Number and basic biographical information are sufficient. Filing is available online through a myUSCIS account or by mail.

After filing, USCIS issues a receipt notice (Form I-797C). For cardholders who still possess the expired or damaged card, the receipt notice extends the card's validity for 36 months from the card's printed expiration date when presented together with the card. For cardholders who no longer have the physical card, USCIS may issue an ADIT stamp at a field office as temporary evidence of permanent resident status. An ADIT stamp appointment can be requested by contacting the USCIS Contact Center.

Other Ways to Locate the Number

• USCIS approval notice (Form I-797): The original I-485 or I-90 approval notice may contain the receipt number that corresponds to the green card number
• USCIS online account: Filing through the myUSCIS portal creates a case history that may display the receipt number
• Prior immigration applications: Previous filings may reference the card number
• I-94 records: Accessible at i94.cbp.dhs.gov, the arrival record may include relevant receipt information
• USCIS Contact Center: Call 1-800-375-5283 for assistance; the Contact Center can schedule an in-person appointment at a local field office if needed

For Employers: When an Employee Cannot Present a Green Card

Permanent residents who have filed Form I-90 to renew their card can present the receipt notice along with their expired card as a valid List A document. Alternatively, employees may present a combination of List B and List C documents. Employers cannot specify which documents an employee presents. The USCIS Handbook for Employers (M-274), Section 13.1 contains the complete list of acceptable documents.

How to Protect Your Green Card Information

For employees:

• Storing the green card in a secure location and carrying it only when needed for travel, employment verification, or official appointments helps reduce the risk of loss or theft
• Keeping a photocopy or secure digital scan of both sides, stored separately from the physical card, provides a backup reference
• Sharing the green card number through unsecured email or text increases the risk of identity fraud
• If a card is lost or stolen, filing Form I-90 initiates the replacement process

For employers:

• The I-9 Document Number field for a green card entry contains a 13-character alphanumeric code, not a 7- to 9-digit A-Number
• Periodic I-9 self-audits help catch and correct errors before a government inspection
• Training hiring managers and HR staff on the difference between the A-Number and the green card number reduces common errors
• Retention of employee document copies beyond what I-9 compliance requires is appropriate only when a company applies a consistent retention policy across all employees

Why Choose Alma for Employment-Based Green Cards?

Success stories from Alma's clients include researchers, entrepreneurs, and healthcare professionals who obtained their green cards through employment-based pathways.

For employees and employers pursuing employment-based green cards, understanding the card's numbers is one part of the process. Getting to the green card requires careful preparation, accurate filing, and experienced legal guidance. Alma's immigration platform combines attorney-led case preparation with technology that provides real-time case tracking, automated deadline management, and secure document organization.

Legal expertise: Alma specializes in employment-based immigration, achieving a 98%+ approval rate through personalized case management that traditional firms struggle to match.

Transparent pricing: Flat-fee pricing with no hidden costs. RFE responses are included in the base fee. Payment plans are available for qualified clients.

Speed and access: Petition preparation in approximately 2 weeks (contingent on client responsiveness; excludes USCIS processing time). Direct attorney communication plus 24/7 portal visibility into case progress.

Whether exploring EB-2 NIW, EB-1A, H-1B, or other visa categories, Alma handles every stage from eligibility assessment through USCIS decision.

Schedule a consultation to discuss green card options with an experienced immigration attorney.