What form establishes eligibility and identity to work in the United States?

The I-9 form is used to establish eligibility and identity to work in the United States. When an employer hires an employee, the I-9 must be completed to verify the individual's identity and their legal authority to work in the country. This process involves providing documentation that proves both the person's identity and their work authorization status, such as a passport or a driver's license paired with a Social Security card.

In contrast, the other forms mentioned serve different purposes. The W-2 form is used to report an employee's annual wages and the taxes withheld from their paycheck, while Form 1040 is the individual income tax return used to report personal income and calculate taxes owed. Form 1099 serves to report various types of income other than wages, salaries, and tips, commonly used for independent contractors. Each of these forms has distinct functions within the context of employment and taxation, which emphasizes why I-9 is the correct choice for verifying work eligibility and identity.