Foreign nationals living in the United States cannot work unless they have received explicit permission under the terms of their visa or other status, or have separately qualified, applied for, and received a work permit.

A work permit is a photo identity card issued by U.S. Citizenship and Immigration Services (USCIS). It is also called an Employment Authorization Document or EAD.

The EAD looks a lot like a driver’s license. Its holders can show it to employers in order to prove their right to work. All U.S. employers must, when hiring a new employee, request proof of their immigration status or right to work—employers who violate this rule can face sanctions.

All green card holders (lawful permanent or conditional residents) automatically have permission to work in the United States. They simply need to show their green card to employers.

Immigrants who go on to become U.S. citizens can, of course, work, and will be able to show their U.S. passport or naturalization certificate to employers.

Foreign nationals who have obtained work-based visas that have been sponsored by U.S. employers are also eligible to work in the United States. For example, such visas include an H-1B (for specialty workers), an L-1 visa (for intracompany transferees), an E-3 visa (only for Australians), and an E treaty trader or treaty investor visa (for employees of companies registered as treaty traders or treaty investors in the United States).