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 is divided into three sections:

1. Employee Information and Attestation: Employees must complete and sign Section 1 of Form I-9 no later than the first day of employment, but not before accepting a job offer. This section requires employees to provide their full legal name, date of birth, social security number, and citizenship status, among other information.

2. Employer Review and Verification: Employers must complete Section 2 of Form I-9 within three business days of the employees first day of work. This section requires employers to examine the employees original documents that establish their identity and employment authorization, such as a passport or drivers license, and record the document information on the form.

3. Reverification and Rehires: Employers must complete Section 3 of Form I-9 when an employees work authorization expires or when they are rehired within three years of the date that the original Form I-9 was completed.

Form I-9 is a fillable form, which means that answers can be typed directly on the form instead of being written by hand. Both employers and employees must still print the completed sections of the form to sign them manually, or employers can upload them to their electronic signature solution, if applicable, to have all parties sign electronically.