The A-Number on a Green Card: Learn the Exceptions First

The A-Number on a green card is the number printed beside the label USCIS# on the front of the card. On Permanent Resident Cards issued since May 2010 it is printed in groups of three digits; USCIS's own published specimen reads `USCIS# 123-456-789`. The agency's glossary defines the A-Number as "a unique seven-, eight- or nine-digit number that the Department of Homeland Security assigned to an alien," so cards held by long-settled residents carry shorter ones. It is not the card's thirteen-character document number, and it is not the twelve-digit USCIS Online Account Number. Your card expires. The number attached to you does not.

I came to this card sideways. I write about reproductive health services: where a referral goes, who holds the record, which office answers when it does not arrive. Many of the people who write to me are adjusting status, and the form that keeps landing on my desk is Form I-693, the immigration medical examination a civil surgeon signs and seals. Edition 01/20/25, fourteen pages. Item 3.E is a row of nine small boxes with `A-` already printed in front of them. That sealed envelope has to reach one specific file inside USCIS, and the A-Number is what makes it land there. I can follow a number from a document to the office holding it. How your case gets decided is a lawyer's question, and I am not a lawyer.

Where the A-Number is printed on each generation of card

USCIS redesigns the Permanent Resident Card every three to five years and states that a new design does not invalidate the old ones: each stays valid until the date on its face. That guidance sits in section 13.1 of the Handbook for Employers (M-274), last reviewed 27 March 2026, which is where the agency publishes specimen images of every design still in circulation. In order of issue:

1. The current card, issued since 30 January 2023. The back is stamped `FORM I-551 Rev (12-2021)`. The front carries surname, given name, country of birth, USCIS#, category, date of birth, sex, "Card Expires" and "Resident Since," with a photo on both sides.
2. The card issued from 1 May 2017. Photo front and back, laser-engraved fingerprint, no signature and no black stripe.
3. The card issued from May 2010, the redesign that turned the card green again. On this version, USCIS notes, "the USCIS/A-Number is also located on the back of the card." The specimen proves it: `CARD# SRC0000000001` sits directly above `A# 000-000-001`.
4. An older card with the DHS seal and a black magnetic stripe, whose specimen prints `A# 000-000-020` in the panel beneath the stripe.
5. Peach Resident Alien cards issued by the Immigration and Naturalization Service, which in USCIS's words "do not have expiration dates and are valid indefinitely."

One thing about the current design deserves saying out loud. The thirteen-character card number is not printed as a labelled field anywhere on it, and the eight-digit number at the top of the back, `99957553` on the specimen, is not that number. Anyone who needs it has to read it out of the machine-readable zone. The 2010 card spelled out both numbers in plain type, labelled, side by side. That was better for the cardholder.

The USCIS# and the A-Number are one number; the card number is another

Readers keep asking whether the USCIS number and the A-Number are the same thing. USCIS answers in one sentence, in section 3.0 of the M-274: "The USCIS Number is the same as the A-Number without the 'A' prefix." Same digits, different label, and the label changed between card generations.

The card number is a different animal, and the machine-readable zone shows both at once. The first line of USCIS's current specimen reads:

`C1USA1234567897MSC0000000110<<`

`C1` is the document code and `USA` the issuing country. The nine characters that follow, `123456789`, are the A-Number, matching `USCIS# 123-456-789` on the front. After a check digit come thirteen characters, `MSC0000000110`: three letters and ten digits, the card's document number. The older specimen does the same with different values, `000000001` in the first field and `SRC0000000001` in the second. Two card generations, one layout.

| Number | Length and shape | What it identifies | Where you read it | Does it change? | |---|---|---|---|---| | A-Number / USCIS# | 7, 8 or 9 digits | The person and their immigration file | Front of the card, labelled USCIS#; back of 2010-design cards, labelled A# | No | | Card (document) number | 13 characters: 3 letters, 10 digits | The physical card | Machine-readable zone on the back; labelled CARD# on 2010-design cards | Yes, with every new card | | USCIS receipt number | 13 characters: 3 letters, 10 digits | One application or petition | Notices of action USCIS mails you | One per case | | USCIS Online Account Number | 12 digits | Your online account | An Account Access Notice, or your account profile | No |

Two of those share a shape, which is where people come unstuck. USCIS describes the receipt number as "a unique 13-character identifier" made of "three letters followed by 10 numbers," and lists the prefixes EAC, WAC, LIN, SRC, NBC, MSC and IOE. Both specimen card numbers use prefixes from that list. My reading is that a card number is the receipt number of the case that produced the card. USCIS does not say so on any page I could find, so treat that as inference.

Everything above is read off USCIS's own specimen images on I-9 Central. I wanted to check the layout against ICAO Doc 9303, the international specification for that zone; the publisher's site refused every request I made for the PDF.

Seven digits, eight digits, nine boxes

Three USCIS documents agree on the range and none rounds it off. The glossary says seven, eight or nine digits. The instructions to Form G-845, edition 08/12/25, say the A-Number "is the letter 'A' followed by a 7, 8, or 9-digit number." The Form I-9 instructions, edition 01/20/25, tell a lawful permanent resident to "enter your 7- to 9-digit USCIS Number (A-Number)."

Now open Form I-485. The 09/04/26 edition gives you nine boxes with `A-` printed outside them, at Part 1, Item 4. Form I-90 gives nine. So do Forms I-693 and N-400. If your A-Number has seven digits, you are holding a nine-box field and two empty squares.

I went looking for the instruction that resolves this. The I-485 instructions run 43 pages, the I-90 instructions eleven, and neither addresses a short A-Number. The common advice is to pad the front with zeros, so that A1234567 becomes A001234567. I have no agency text for it and will not dress folk practice up as an instruction. If your number is short and the stakes are high, the USCIS Contact Center owns the question.

The form anticipates a second exception that surprises people more. Item 5, immediately below: "Have you ever used, or been assigned, any other A-Number?" A single person can end up with two, and USCIS asks about it on the face of the application.

What the expiration date does to your A-Number

The front field is labelled "Card Expires." On the current specimen it reads `10/26/32`, encoded as `321026` in the second line of the machine-readable zone. The dates behind it move more than most residents expect:

• A Permanent Resident Card can be valid for 10 years, in the wording USCIS uses in Welcome to the United States: A Guide for New Immigrants (M-618).
• A conditional permanent resident receives a card valid for two years, and USCIS is explicit that you cannot renew it. You file to remove the conditions during the 90 days before it expires.
• Under 8 CFR 264.5(b)(2), you must apply for a replacement once the card expires within six months.
• Since 10 September 2024, a Form I-90 receipt notice extends the card's validity 36 months past the date on its face. That figure was 24 months before the change.
• The peach INS cards have no expiration date at all, and they are the exception to the exception: 8 CFR 264.5(c)(1) obliges the holder of a prior-edition card issued on Form AR-3, AR-103 or I-151 to apply for a replacement regardless.

Every one of those events changes the card. None of them changes the A-Number. A replacement card arrives with a fresh thirteen-character document number, a fresh expiration date and the same USCIS# you had before.

Which number the form in front of you is asking for

A wrong number here costs weeks. The state of each form as of 6 September 2026:

Form I-485 is the volatile one. The current edition is 09/04/26, published on 4 September; USCIS also accepts the 01/20/25 edition. On 18 September 2026 a 09/18/26 edition takes over with no grace period: USCIS will reject the 01/20/25 and 09/04/26 editions if they are postmarked or filed electronically on or after that date. Check the edition date at the foot of every page before the package goes in the envelope.

Form I-90, edition 01/20/25, asks for the A-Number at Item 1 and the USCIS Online Account Number at Item 2. It does not ask for your card number. I searched the whole seven-page form; there is no field for it, which contradicts much published advice about the "USCIS Card Number" on Form I-90.

Form I-9, edition 01/20/25, gives a lawful permanent resident one instruction in Section 1: "Enter USCIS or A-Number." The employer's half is a separate question. In Section 2 the employer copies the document title, issuing authority, document number and expiration date from the document the employee handed over.

Form I-693 and Form N-400, both edition 01/20/25, each open with a nine-character A-Number field. On the I-693 it sits at Item 3.E, with the online account number at 3.F.

To transcribe the number without a mistake: read the line labelled USCIS# on the front of the card, or A# on the back of a 2010-design card; write down the digits alone, dropping the hyphens and the letter A; count them and accept seven, eight or nine; compare that count to the nine boxes on your form; and check the digits against a USCIS notice before you sign.

Where the number goes once you have written it

The A-Number is a registration number and the card is a registration document. That is not a metaphor. 8 CFR 264.1(b) lists the forms that "constitute evidence of registration," and Form I-551, Permanent Resident Card, is on it. The same regulation at 264.1(a) lists Form I-485 among the prescribed registration forms, which is why the application is titled Application to Register Permanent Residence. A lawful permanent resident who turns 14 registers again by filing Form I-90, and residents aged 18 and over must carry their evidence of registration at all times.

The regulation also says what happens at the end. Under 8 CFR 264.1(d), when a person naturalizes the registration document goes back to a USCIS office. The number stays in the file, and Form N-400 asks for it on page one.

That is as far as I can take you: from a line of type on a card to the office that holds the record it points at. What that office decides about your case is not a question a service journalist should be answering.

Frequently asked questions

Is the USCIS number on my green card the same as my A-Number?

Yes. USCIS states in its Handbook for Employers that "the USCIS Number is the same as the A-Number without the 'A' prefix." The card prints it on the front after the label USCIS#, in groups of three digits. Any form asking for an Alien Registration Number wants those same digits.

Where do I find the A-Number on my green card?

On the front, on the line labelled USCIS#. Cards issued from May 2010 also print it on the back, labelled A#, and older cards with a black magnetic stripe print it in the panel beneath the stripe. In USCIS's published specimens the digits are grouped in threes, as in 000-000-001.

What is the 13-character number on my green card?

That is the card's document number: three letters followed by ten digits. It identifies the physical card rather than you, and changes every time USCIS issues a replacement. On cards made since January 2023 it appears only inside the machine-readable zone on the back, with no printed label.

What do I write if my A-Number has only 8 digits?

USCIS accepts seven-, eight- and nine-digit A-Numbers, and the Form I-9 instructions say so in those words. Neither the I-485 nor the I-90 instructions explain what to do with spare boxes on a nine-box field. The common practice is to add leading zeros, though no USCIS instruction I found states it.

Does my A-Number change when I renew my green card?

No. A renewal through Form I-90 produces a new card with a new thirteen-character document number and a new expiration date. The A-Number carries across unchanged. It is the number USCIS uses to locate your file, and it follows you through adjustment of status, every replacement card and naturalization.

Which number goes on Form I-9, the A-Number or the card number?

They land in different places. In Section 1 the employee enters the USCIS Number or A-Number, which the instructions describe as 7 to 9 digits. In Section 2 the employer records the document title, issuing authority, document number and expiration date taken from the card the employee presented.

Do I keep my A-Number after I become a US citizen?

The number stays in USCIS records; the card does not stay with you. Under 8 CFR 264.1(d), evidence of registration must be forwarded to a USCIS office when a person naturalizes. Form N-400, edition 01/20/25, asks for the A-Number in a nine-character field on its first page.