The back of a Permanent Resident Card carries the data federal officers actually use to verify your status. If you’re wondering what’s on the back of a Permanent Resident Card, the short answer is: a form number and manufacture date, a 13-character receipt number, return-mail instructions, your class of admission code, layered anti-counterfeiting features, and a machine readable zone that encodes your A-Number, date of birth, gender, card expiration, country of birth, and name. The front is what you look at. The back is what gets scanned.
Administrative Text at the Top
The reverse side prints the form number (I-551) and the date the card was manufactured, which tells an officer which security generation the card belongs to. Near the top you’ll also find a 13-character receipt number that links directly to the application USCIS approved when it issued the card.1U.S. Citizenship and Immigration Services. Receipt Number The first three letters identify the facility that processed the case: LIN for Nebraska, SRC for Texas, EAC for Vermont, WAC for California, and IOE for electronic filing.
Printed instructions tell anyone who finds a lost card to mail it to the Department of Homeland Security at a processing facility in London, Kentucky. If your own card goes missing, the return-mail line isn’t your recovery path. You file Form I-90 with USCIS to get a replacement.2U.S. Citizenship and Immigration Services. I-90, Application to Replace Permanent Resident Card (Green Card)
The Machine Readable Zone
The bottom portion is a machine readable zone, or MRZ, formatted to the international standard for credit-card-sized identity documents. It runs exactly 90 characters across three lines of 30 each.3International Civil Aviation Organization. Doc 9303 Machine Readable Travel Documents – Part 5 Filler “<” symbols pad any unused space so each line hits the required length. This block is what Customs and Border Protection scans when you reenter the country.
Line One
The first two characters give your residency classification. “C1” means you reside inside the United States. “C2” identifies a permanent resident commuter living in Canada or Mexico. Positions 3 through 5 hold “USA” as the issuing country. Your nine-digit A-Number sits in positions 6 through 14.4U.S. Citizenship and Immigration Services. A-Number/Alien Registration Number/Alien Number The remaining positions encode the application receipt number and the immigrant case number, with “<” filling any leftover space.
Line Two
The second line packs in your date of birth in YYMMDD format (positions 1 through 6), a check digit, your gender, your card’s expiration date in YYMMDD (positions 9 through 14), another check digit, and your country of birth. Those check digits are single numbers calculated from the adjacent data. Scanning equipment recalculates them on the spot, and a mismatch flags the card for closer inspection. That’s the primary anti-tampering mechanism inside the MRZ itself.
Line Three
The third line spells out last name, first name, and middle name, separated by double “<” characters. If space allows, the first initials of your father and mother appear at the end. Longer names push those initials out entirely. This line carries no check digit.
Class of Admission Code
A short alphanumeric code on the card shows how you obtained permanent residence. USCIS calls these “classes of admission,” and they map to specific categories under the Immigration and Nationality Act.5Department of Homeland Security Office of Homeland Security Statistics. Immigrant Classes of Admission Common examples:
- IR1, spouse of a U.S. citizen, new arrival from abroad
- IR6, spouse of a U.S. citizen, adjusted status from inside the U.S.
- CR1, conditional resident spouse, new arrival
- F11, unmarried adult son or daughter of a U.S. citizen, new arrival
- E11, employment-based first preference
Codes beginning with “C” signal conditional residence, meaning the card expires after two years instead of ten and you’ll need to file a petition to remove conditions before it lapses.6U.S. Citizenship and Immigration Services. Removing Conditions on Permanent Residence Based on Marriage The difference between “new arrival” and “adjustment” codes reflects whether you entered on an immigrant visa or changed status from within the country.
Security Features You Can See and Feel
The current card design, introduced in 2023, layers several anti-counterfeiting technologies onto the back.7U.S. Citizenship and Immigration Services. USCIS Redesigns Green Card and Employment Authorization Document Optically variable ink shifts color when you tilt the card under light. Holographic images reflect in patterns unique to genuine cards. A layer-reveal feature at a partial window on the back photo box shows a secondary image only at certain angles or under specific lighting.
Micro-images and fine patterns are woven across the surface. They read as solid lines to the naked eye and reveal detail only under magnification, and they overlap the printed text and MRZ so that altering any data destroys the pattern. Tactile printing gives some areas a raised texture you can feel with a fingernail. Ultraviolet features appear only under UV lamps of the type border officers routinely carry. Verification therefore combines visual checks, touch, UV light, and machine scanning.
What the Expiration Date on the Back Means
The expiration date encoded in the MRZ’s second line tells any scanner immediately whether the card is current. A standard card runs ten years from issuance. Conditional cards run two years.6U.S. Citizenship and Immigration Services. Removing Conditions on Permanent Residence Based on Marriage
An expired card doesn’t mean you’ve lost permanent resident status, but it does mean the card no longer proves that status. For a standard ten-year card, file Form I-90 for a replacement, ideally before expiration, since processing regularly stretches several months.2U.S. Citizenship and Immigration Services. I-90, Application to Replace Permanent Resident Card (Green Card) Conditional residents file something different: Form I-751 for marriage-based cases or Form I-829 for investor cases, to remove the conditions rather than simply replace the card. Missing that deadline can trigger removal proceedings, which is why the two-year date printed and encoded on the back is worth treating as a hard deadline.