One of the many items on every employer's checklist while hiring a new employee is to verify the individual's identity and authorization to work in the United States. Employers are required to ask new hires to complete a portion of Form I-9, Employment Eligibility Verification (Form I-9) on the first day of employment and provide documentation supporting their work authorization for inspection within the first three business days. This obligation also extends to re-verifying documents with an expiration date on the work authorization and rehires of former employees.