How to Read a Permanent Resident Card

A Permanent Resident Card can look like a small plastic card full of letters, numbers, and security features. The easiest way to understand it is to read it from front to back and keep each number tied to its exact location.

That matters when you’re completing Form I-9. The USCIS number, A-number, and card or document number are related, but they are not the same number.

What a Permanent Resident Card is also called: Green Card and Form I-551

A Permanent Resident Card is commonly called a Green Card. Its formal name is Form I-551, Permanent Resident Card, also known as the Alien Registration Receipt Card.

You may see these names used for the same document:

• Permanent Resident Card
• Green Card
• Form I-551
• Alien Registration Receipt Card

The card proves permanent resident status when it is valid and properly issued. But simply finding a number or matching the card’s printed information does not, by itself, confirm that the card is valid. Reading the card and checking its status are separate tasks.

How to read the front of the Permanent Resident Card

The front contains the main identity details. Start there before trying to interpret the codes on the back.

Photo and personal information

The front generally shows:

• The cardholder’s photograph
• Full name
• Date of birth
• Country of birth
• Sex
• USCIS Number
• Dates connected to the card or the person’s permanent resident record
• A category code

The exact placement can vary between card designs, so focus on the label next to each item rather than relying only on where it appears.

The name should be read as it is printed on the card. Depending on the design, the name may be shown in separate fields or in a different order from the way names are normally written in conversation.

The date of birth identifies the cardholder. It is different from any date showing when permanent residence began or when the card expires.

The country of birth is also a separate identity field. It should not be confused with citizenship or nationality.

The sex field is another personal detail printed on the front. As with the other biographic fields, it is there to identify the cardholder. It is not a card number or an immigration category.

Dates on the front

A Permanent Resident Card can show more than one date. When reading a date, first identify its label. A date may relate to the holder’s record, the start of permanent residence, or the card’s expiration.

Do not treat every date as the expiration date. For Form I-9, use the date connected to the card’s expiration, following the form’s instructions and the information printed on the document.

The category code

The front also includes a short category code. This code describes the immigration category connected to the person’s permanent resident status.

It is not the same thing as:

• The USCIS number
• The A-number
• The card or document number
• The cardholder’s date of birth

Because category codes can be easy to misread, copy the letters and numbers exactly as printed. A category code is useful identifying information, but it does not replace the number requested in a particular Form I-9 field.

Where to find the USCIS number, A-number, and other identifying numbers

Several names are used for numbers connected with a Permanent Resident Card. This is where many mistakes start.

USCIS Number and A-number

The USCIS Number is printed on the front of the card. It is an identifying number assigned to the person’s immigration record.

This number is also commonly referred to as the A-number, or Alien Registration Number. In some contexts, it may appear with an A before the digits. The card itself may display the number without that letter, depending on the design and field label.

The key point is location: look for the number identified as the USCIS Number on the front. Do not assume that the longest number on the card is automatically the USCIS number.

Card number, green card number, and document number

The card number is a different identifier. It is also often called the green card number or Permanent Resident Card document number.

One way it is described is by its location on the back: it appears in the last 13 characters of the first line, followed by two spaces. Since the back uses a structured, machine-readable layout, the number may be surrounded by other characters and may not look like a simple label followed by digits.

This is the number people usually mean when they ask for the document number on a Permanent Resident Card.

The “I-551 number” wording

People sometimes ask for the I-551 number on a Permanent Resident Card. The phrase can cause confusion because Form I-551 is the name of the document, while the card contains more than one identifying number.

Before entering a number, check what the request actually asks for:

• If it asks for the USCIS Number or A-number, use the number labeled that way on the front.
• If it asks for the document number, card number, or green card number, use the card identifier found in the appropriate location on the back.
• If it asks for a category, use the category code rather than either number.

Never swap these numbers simply because they all appear on the same card.

How to read the back of the card line by line

The back contains a structured set of lines. Looking at the lines in order makes the information easier to sort.

First line: card code and card number area

The first line begins with C1 or C2. These are card-related codes shown in the back-of-card structure.

The same line also contains the card’s identifying information. The green card number is described as being in the last 13 characters of that first line, followed by two spaces.

Read this line carefully from left to right. Do not take the first group of numbers you see and assume it is the document number. The position at the end of the line is what matters.

Second line: date of birth

The second line contains the cardholder’s birth date in YY/MM/DD format.

For example, the order is:

1. Two digits for the year
2. Two digits for the month
3. Two digits for the day

This format is different from the way a date may appear on the front. If you are copying it into a form, use the date format requested by that form rather than changing the date’s meaning.

Third line: the cardholder’s name

The third line contains the holder’s:

• Last name
• First name
• Middle name

The name may appear in a compact format because the back line is designed to store information in a standard pattern. Spacing or symbols may not look like ordinary printed text.

Use the front of the card to confirm how the name is displayed for normal reading. Use the back line as a structured record, not as a sentence.

What the codes, dates, and category information mean

The card contains several kinds of information, and each kind answers a different question.

• Biographic information identifies the person. This includes the photo, name, birth date, country of birth, and sex.
• Record numbers connect the cardholder with an immigration record. The USCIS Number or A-number belongs in this group.
• Card numbers identify the physical Permanent Resident Card. This is the number often requested as the document number.
• Codes describe card or immigration-category information. The front category code and the back C1 or C2 code should not be treated as the same thing.
• Dates identify events or limits tied to the person or card. Read the label before deciding what a date means.

A number’s meaning comes from both its label and its location. Looking only at the digits is risky, especially if you are copying information into Form I-9.

Which Permanent Resident Card number belongs on Form I-9

For Form I-9, a Permanent Resident Card is a List A document. The form asks for information about the document, including its title, document number, and expiration date when one is shown.

For the document number field, use the Permanent Resident Card’s card number, also called the green card number or document number. This is the number identified from the back-of-card line structure, not the USCIS Number printed on the front.

A simple Permanent Resident Card I-9 example looks like this:

• Document title: Permanent Resident Card
• Document number: The card or green card number from the back
• Expiration date: The expiration date printed on the card, entered in the format requested by Form I-9

Do not enter the following in the document number field unless the form specifically asks for it:

• The USCIS Number
• The A-number
• The category code
• The C1 or C2 code
• The birth date

If a field or document is unclear, pause and check the form’s current instructions or ask a qualified employment-document professional. A number that looks plausible can still be the wrong number for that field.

How the redesigned 2023 Green Card may look different

Redesigned Green Cards introduced in 2023 may not look exactly like older cards. A different appearance does not automatically mean that a card is incorrect.

The newer design includes:

• Enhanced optically variable ink
• Highly secure holographic images on the front and back
• A new layer reveal feature

These features are part of the card’s security design. They may affect how the card looks when viewed from different angles or under different conditions.

The basic reading method stays the same: identify the personal details on the front, then read the structured lines on the back. A newer card may place or style information differently, so rely on the printed labels and line positions instead of memorizing one visual layout.

What to check when comparing a card's appearance and information

When you need to read a card, work through it in a fixed order:

1. Check the front photo and personal details. Look at the name, birth date, country of birth, and sex.
2. Find the USCIS Number. Keep it separate from the card or document number.
3. Read the dates by their labels. Do not assume the first date you see is the expiration date.
4. Note the category code. It describes a category, not a person’s main record number.
5. Turn to the back. Read the first line, second line, and third line in order.
6. Locate the document number. Use the number in the correct part of the first back line.
7. Compare the information across both sides. Names and birth dates should be read as connected identity details.

This process helps you identify what is printed on the card. It does not confirm that the document is valid, unexpired, genuine, or acceptable in every situation. Those questions require a separate review.

Permanent Resident Card questions that commonly cause confusion

How do I read a Permanent Resident Card?

Start with the front. Identify the photo, name, date of birth, country of birth, sex, USCIS Number, dates, and category code.

Then read the back from top to bottom. The back includes the C1 or C2 code, the birth date in YY/MM/DD format, the holder’s name, and the card number within the first line’s structured information.

What do the numbers on the back mean?

The numbers are arranged by position. The first line begins with C1 or C2 and includes the card number area. The second line gives the birth date in YY/MM/DD format. The third line gives the person’s name.

Not every number on the back is the green card number. Use the number’s location and the purpose of the form or request.

What does a Green Card look like in 2025?

A Green Card may show the familiar front identity information and a structured back. Cards from the redesigned 2023 series can include optically variable ink, holographic images on both sides, and a layer reveal feature.

Cards may differ in design and appearance. Compare the printed information carefully instead of deciding based on color or appearance alone.

How can I verify that a Permanent Resident Card is valid?

Reading the card can help you find its numbers and dates, but it does not verify validity. If you need help confirming validity or completing Form I-9, speak with a qualified immigration professional or employment-document professional.