The Immigration Reform and Control Act of 1986 (IRCA) makes it illegal for an employer to discriminate with respect to hiring, firing, or recruitment or referral for a fee, based upon an individual's citizenship or immigration status. The law prohibits employers from hiring only U.S. citizens or lawful permanent residents unless required to do so by law, regulation or government contract.

Employers may not refuse to accept lawful documentation that establishes the employment eligibility of an employee, or demand additional documentation beyond what is legally required, when verifying employment eligibility (i.e., completing the Department of Homeland Security (DHS) Form I-9), based on the employee's national origin or citizenship status. It is the employee's choice which of the acceptable Form I-9 documents to show to verify employment eligibility.

IRCA also prohibits retaliation against individuals for asserting their rights under the Act, or for filing a charge or assisting in an investigation or proceeding under IRCA.

IRCA's nondiscrimination requirements are enforced by the Department of Justice's Civil Rights Division's Immigrant and Employee Rights Section (IER).

IRCA generally makes employment of unauthorized aliens unlawful (8 U.S.C. §1324a), while prohibiting discrimination in employment based on national origin or citizenship status (8 U.S.C. §1324b).

Under the Immigration Reform and Control Act of 1986 (IRCA), employers in Maine, as in all other states, are prohibited from discriminating against individuals in hiring, firing, or recruitment based on their citizenship or immigration status. Maine employers must not hire only U.S. citizens or lawful permanent residents unless explicitly required by federal law, regulation, or government contract. They are also barred from rejecting valid documents for employment eligibility verification or demanding more documents than are legally necessary when completing the DHS Form I-9. Employees have the right to present any acceptable documents from the Form I-9 list to prove their eligibility to work. Additionally, IRCA protects individuals from retaliation if they seek to enforce their rights under the Act or participate in an investigation or proceeding related to the Act. The enforcement of these nondiscrimination provisions falls under the Department of Justice's Civil Rights Division's Immigrant and Employee Rights Section (IER). Furthermore, IRCA makes it illegal to employ unauthorized aliens and sets forth penalties for such violations.