Form I-9, officially the Employment Eligibility Verification, is a United States Citizenship and Immigration Services form mandated by the Immigration Reform and Control Act of 1986. It is used to verify the identity and legal authorization to work of individuals hired for employment in the United States. The form requires both employees and employers (or authorized representatives of the employer) to complete it.

The I-9 form consists of several sections, including employee information and attestation, employer review and verification, lists of acceptable documents, and preparer and/or translator certification for Section 1. Employees must provide documentation to their employers to show their identity and authorization to work. Employers must physically examine the documentation presented by the employee to complete Form I-9, or examine them consistent with an alternative procedure authorized by the Secretary of DHS.

The form also requires prospective employees to attest, under penalty of perjury, that they are in one of the following categories: a U.S. citizen, a U.S. non-citizen national, a lawful permanent resident, or an alien authorized to work. The employer must accept any valid document or combination of documents specified in the I-9 form as long as the documents appear genuine.

In October 2004, new legislation made it possible to complete the I-9 electronically. The latest version of Form I-9 is available on the USCIS website, and employers must ensure they are using the most current version of the form. The USCIS updates the Form I-9 periodically.

Starting November 1, 2023, employers who fail to use the 08/01/23 edition of Form I-9 may be subject to all applicable penalties under section 274A of the INA, 8 U.S.C. 1324a, as enforced by U.S. Immigration and Customs Enforcement (ICE).