A green card is a federal immigration document, officially titled Form I-551, Permanent Resident Card, issued by U.S. Citizenship and Immigration Services. It proves that its holder is a lawful permanent resident of the United States with the right to live and work in the country indefinitely. The same wallet-sized card serves as proof of identity, employment authorization, and permission to re-enter the U.S. after international travel.
An Immigration Document, Not a Visa
Within the USCIS system, the green card carries the formal designation Form I-551. The form is the primary evidence that the federal government has granted someone lawful permanent resident status under the Immigration and Nationality Act.1U.S. Citizenship and Immigration Services. List A Documents That Establish Identity and Employment Authorization That status is different from a temporary visa. It does not tie you to a set departure date, and you do not need employer sponsorship to remain in the country.
The I-551 designation appears across government databases, tax systems, and employment verification platforms. Federal agencies use it to confirm a resident’s eligibility for benefits like Social Security (after enough work credits) and for military service. The Department of Homeland Security maintains the underlying record, which distinguishes permanent residents from people on temporary visas who must eventually leave or extend their stay.
What the Card Itself Contains
Each green card displays the holder’s full legal name, date of birth, photograph, signature, country of birth, and the date the card was issued. It also includes an Alien Registration Number, commonly called an A-Number, a unique seven-, eight-, or nine-digit identifier assigned by the Department of Homeland Security.2U.S. Citizenship and Immigration Services. A-Number/Alien Registration Number/Alien Number A machine-readable zone on the back encodes the holder’s biographical data, immigration case number, and card expiration date.
To prevent counterfeiting, USCIS redesigns the card every three to five years and layers it with multiple security features.1U.S. Citizenship and Immigration Services. List A Documents That Establish Identity and Employment Authorization These include holographic images embedded within the card layers, specialized optical ink, micro-printing, and an embedded RFID chip that allows electronic verification at ports of entry. The most recent card design was introduced on January 30, 2023. Older versions remain valid until their printed expiration date.
What the Card Lets You Do
Prove You Can Work
The green card is one of the most straightforward documents for proving your right to work. It is classified as a List A document on Form I-9, the Employment Eligibility Verification form that every U.S. employer must complete for new hires.1U.S. Citizenship and Immigration Services. List A Documents That Establish Identity and Employment Authorization A List A document satisfies both the identity and employment authorization requirements at once, so you do not need to present a separate driver’s license, Social Security card, or work permit. An employer who sees a valid green card has no reason to ask for anything else.
If your physical card has not yet arrived or is being renewed, you can prove the same thing with temporary evidence. A foreign passport containing a temporary I-551 stamp (sometimes called an ADIT stamp) or a machine-readable immigrant visa with an I-551 notation also qualifies as a List A document for I-9 purposes.3U.S. Citizenship and Immigration Services. Lawful Permanent Residents (LPR) When the stamp does not include an expiration date, it serves as proof of permanent residence for one year from the date of admission.
Re-enter the United States
When you return to the U.S. from international travel, you must present your green card to Customs and Border Protection officers at the port of entry. The card confirms that you are coming back to your permanent home and have not abandoned your status. You still need a valid passport from your country of citizenship for the international travel itself. The green card is not a passport substitute.
Extended time abroad can complicate re-entry. An absence of more than 180 days creates a legal presumption that you have broken your continuous residence, and 365 days or more can lead USCIS to treat your status as abandoned unless you obtained a re-entry permit before leaving.4U.S. Citizenship and Immigration Services. Chapter 3 – Continuous Residence
How Long the Card Lasts
A standard green card is valid for ten years from the date of issuance. The card’s expiration does not end your permanent resident status. That status is generally permanent unless a judge orders removal or you formally abandon it. An expired card, however, cannot be used to prove your right to work or re-enter the country, so keeping it current matters.
You can file Form I-90 to replace your card once it is within six months of expiring, or after it has already expired.5U.S. Citizenship and Immigration Services. Form I-90, Instructions for Application to Replace Permanent Resident Card Once USCIS receives the application, you will get a Form I-797 receipt notice that automatically extends the validity of your expired card for 36 months, so you can continue working and traveling while the renewal is processed.6U.S. Citizenship and Immigration Services. USCIS Extends Validity of Expired Permanent Resident Cards from 24 Months to 36 Months for Renewals
Conditional Green Cards
Not every green card lasts ten years. Residents who obtained permanent status through marriage to a U.S. citizen or through certain investment categories receive a conditional green card that expires after just two years.7Office of the Law Revision Counsel. 8 USC 1186a – Conditional Permanent Resident Status for Certain Alien Spouses and Sons and Daughters To keep your status, you must file a petition to remove the conditions during the 90-day window before the card’s second anniversary. Marriage-based residents file Form I-751, and investors file Form I-829.8U.S. Citizenship and Immigration Services. I-90, Application to Replace Permanent Resident Card (Green Card) Missing this deadline can result in automatic termination of your status.
Obligations That Come With the Card
Carry It at All Times
Federal law requires every lawful permanent resident who is 18 or older to carry their green card in their personal possession at all times. Failing to do so is a misdemeanor punishable by a fine of up to $100, up to 30 days in jail, or both.9Office of the Law Revision Counsel. 8 USC 1304 – Forms for Registration and Fingerprinting Enforcement varies in practice, but immigration officers, employers, and government agencies can all ask to see the card, and not having it available can create delays at airports, border crossings, and during employment verification.
Report Address Changes
Federal law also requires all noncitizens in the United States, including permanent residents, to report a change of address to USCIS within 10 days of moving.10U.S. Citizenship and Immigration Services. How to Change Your Address You can do this online through a USCIS account or by mailing a paper Form AR-11. Ignoring the requirement is a misdemeanor that can carry a fine of up to $200, up to 30 days in jail, and can separately be used as a basis for removal proceedings.11Office of the Law Revision Counsel. 8 USC 1306 – Penalties
File U.S. Taxes on Worldwide Income
Holding a green card makes you a U.S. tax resident. You must report your worldwide income to the IRS, not just money earned inside the United States, regardless of where you physically live.12Internal Revenue Service. Tax Information and Responsibilities for New Immigrants to the United States If you hold foreign bank or investment accounts, you may also need to file a Report of Foreign Bank and Financial Accounts (FBAR) with the Treasury Department and, depending on total account values, attach Form 8938 to your tax return.
What the Card Does Not Make You
A green card proves permanent residence, not citizenship. Lawful permanent residents cannot vote in federal, state, or local elections, and voting illegally is a federal crime punishable by up to one year in prison and a fine.13Office of the Law Revision Counsel. 18 USC 611 – Voting by Aliens Voting in violation of any election law also makes a permanent resident deportable, as does falsely claiming U.S. citizenship on a job application, government form, or any similar document.14Office of the Law Revision Counsel. 8 USC 1227 – Deportable Aliens Certain criminal convictions, particularly controlled substance offenses under federal law, can also make a green card holder deportable or inadmissible on return from travel abroad.15Office of the Law Revision Counsel. 8 USC 1182 – Inadmissible Aliens Permanent residence is durable, but the card is not a substitute for citizenship, and the protections that come with citizenship require going through the naturalization process.