Form I-9 Fundamentals | Anatomy of the I-9 Form

What Is an I-9 Form? I-9 Document Basics for Employers

The I-9 form is a mandatory employment eligibility document required by U.S. law. It verifies a new hire's identity and legal right to work in the U.S. Every employer must complete and retain a Form I-9 for each employee. In this guide, we’ll break down what the I-9 form is, who fills it out, what documents are required, and how to stay compliant.

What Is Form I-9 and Why It Matters

Form I-9 is a mandatory employment eligibility verification document required by U.S. employers. It ensures that all employees are legally authorized to work in the United States. Employers must complete and retain a Form I-9 for each new hire, verifying identity and work authorization through supporting documentation.Failing to properly complete or maintain I-9 forms can result in substantial penalties—even criminal liability in severe cases.

The Birth of the I-9 Form and Its Purpose

The I-9 form was created by the Immigration Reform and Control Act of 1986 (IRCA) to curb unauthorized employment. It made it illegal for employers to knowingly hire or retain unauthorized workers and introduced strict civil and criminal penalties for non-compliance.After the events of September 11, 2001, the government elevated immigration enforcement, consolidating responsibilities under the Department of Homeland Security (DHS). Today, U.S. Citizenship and Immigration Services (USCIS) administers the I-9 program, while Immigration and Customs Enforcement (ICE) enforces it through audits and investigations.

What Are the Sections of Form I-9?

The I-9 form has four critical sections that assign responsibility to both the employee and employer. Each section includes legally binding attestations.

Section 1: Employee Information and Attestation

Who Completes It?

The employee — by their first day of work.

‍What’s Required?‍

Name, address, and identifying information
Attestation of work authorization:

U.S. Citizen
U.S. Non-Citizen National
Lawful Permanent Resident
Authorized to work in the U.S. (must provide A-Number, I-94, or foreign passport)

Legal Risk: The employee signs under penalty of perjury. Inaccuracies can trigger investigations.

Section 1 image—"Screenshot of Form I-9 Section 1 showing employee information and attestation fields for identity and work authorization.

Section 2: Employer Review and Verification

Who Completes It?

The employer—within 3 business days of the employee’s start date.

‍What’s Required?‍

Review of original, unexpired documentation
Verification that the documents appear genuine

Acceptable Documents:‍

List A: Proves identity & work authorization
List B: Identity only
List C: Work authorization only

Legal Risk: Employer signature confirms lawful documentation—errors can lead to ICE penalties.

Screenshot of Form I-9 Section 2 displaying employer review and verification area, with fields for document review and employer signature.

Supplement A: Preparer/Translator Certification

Used only when an employee needs help filling out Section 1.

Each preparer must sign a separate form.
Employers must ensure it’s properly completed and attached.

Screenshot of Form I-9 Supplement A for preparer or translator certification, used when employees need assistance completing Section 1.

Supplement B: Re-verification and Rehires

Required:

When work authorization expires
When an employee is rehired within 3 years
When an employee’s name changes

Reminder: This section also carries legal weight—sloppy completions = exposure.

Screenshot of Form I-9 Supplement B for re-verification and rehire documentation, including expiration and name change sections.

Why I-9 Compliance Can't be Ignored

Even minor mistakes on I-9 forms can lead to:

Thousands in fines
Failed audits
Criminal penalties for willful violations

Modern I-9 compliance requires more than manual effort. Employers are increasingly turning to automated compliance software that provides audit trails, alerts, and centralized document storage.

Frequently Asked Questions About the I-9 Form

What is a Form I-9?

The Form I-9 is a federal document used to verify the identity and employment authorization of individuals hired for employment in the United States. All U.S. employers are required to complete and retain a Form I-9 for every employee they hire.

Who is required to complete Form I-9?

All employees, including citizens and noncitizens, must complete Section 1 of Form I-9 at the time of hire. Employers must complete Section 2 within three business days of the employee’s start date.

What documents are required for Form I-9?

Employees must provide documentation that establishes both identity and employment authorization. These can include a U.S. passport, a green card, a driver’s license and Social Security card combination, or an Employment Authorization Document.

Is Form I-9 required for remote employees?

Yes, employers must complete Form I-9 for remote workers using an authorized representative or alternative remote verification procedures if permitted under current DHS guidelines.

What happens if I-9 compliance is not followed?

Failure to comply with I-9 requirements can result in civil fines, criminal penalties, and potential loss of business licenses. Penalties apply whether violations are intentional or due to simple errors.

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