Under the Immigration Reform and Control Act of 1986 (IRCA), it is illegal for employers to knowingly employ undocumented workers. When employees are hired, their employer is required to ask for documents. The documents must show their identity and authorization to work in the U.S. Those documents must “reasonably appear to be genuine.”
Employers must terminate, or refuse to hire, an undocumented worker if the find the worker is unauthorized to work. But, the employer cannot use immigration status as an excuse to fire undocumented workers who make discrimination complaints. Undocumented workers are covered by federal discrimination laws. The law prohibits employers from retaliating against workers who assert their legal rights. If an employer retaliates against an employee for exercising their right to file a discrimination complaint, the employer is breaking the law.
For more information, see question number 11 on our immigration status discrimination page, or read the text of the law.