Form I-9 verifies that a new hire is authorized to work in the United States. The employee fills Section 1 on day one; the employer completes Section 2 within three business days after examining acceptable documents. You don't mail it to USCIS — the employer keeps it on file. The field that trips people up is the citizenship/immigration status attestation in Section 1.
What Form I-9 Is
Form I-9, "Employment Eligibility Verification," is how U.S. employers confirm the identity and work authorization of everyone they hire. Every employer must complete one for each employee, citizen or not. Unlike most government forms, I-9 is never filed with an agency — it's retained by the employer and produced only if audited.
It has two halves: the employee attests to their status and signs (Section 1), and the employer records the documents they examined and signs (Section 2). Always use the current edition from uscis.gov — USCIS reissues the form, and an outdated version can be rejected in an audit.
Section 1: The Citizenship Attestation
The employee completes Section 1 no later than their first day of work. It asks for name, address, date of birth, and — the field that causes the most corrections — which of four status categories applies:
- A citizen of the United States
- A noncitizen national of the United States
- A lawful permanent resident — requires the A-Number / USCIS Number
- A noncitizen authorized to work — requires the work-authorization expiration date and a document number (e.g. from an EAD or I-94)
Pick the box that matches your actual status, and fill only the extra fields that box requires. Checking a box but leaving its required number blank is the single most common Section 1 error.
Section 2: List A, B, and C Documents
The employer examines the employee's documents and records them in Section 2. The employee chooses which to present:
- One List A document — proves identity and work authorization on its own (U.S. passport, Permanent Resident Card, or an Employment Authorization Document from Form I-765), or
- One List B + one List C document — a List B identity document (e.g. driver's license) plus a List C work-authorization document (e.g. Social Security card, birth certificate)
The employer records the document title, issuing authority, number, and expiration, then signs and dates within three business days of the hire.
Do I file Form I-9 with USCIS?
No. Form I-9 is not submitted to USCIS or any agency. The employer keeps it — for at least three years after the hire date or one year after employment ends, whichever is later — and presents it only during an inspection. That retention duty is why accuracy matters: an error can sit undiscovered for years until an audit surfaces it.
What's the difference between Form I-9 and Form W-4?
They're both new-hire paperwork, but they answer different questions. I-9 proves you're authorized to work; the W-4 tells your employer how much tax to withhold. New hires typically complete both on day one, and both reuse the same core identity — name, address, SSN — which is exactly the kind of repeated data entry an AI form filler removes by holding it in one reusable profile.
What causes most Form I-9 errors?
Missed deadlines (Section 2 not done within three business days), a blank required field under the chosen status box, over-documentation (asking for more documents than the rules allow, which is a compliance violation), and using an expired form edition. Because the employee and employer sections repeat the same identity details, entering them once and reusing them removes the transcription slips that turn into audit findings.