"The Immigration and Nationality Act (INA) prohibits employers, including federal agencies, from knowingly hiring non-U.S. nationals (aliens) who are not authorized to work in the United States. By statute, certain aliens are generally authorized to work in the United States, and the Secretary of the Department of Homeland Security (DHS), by regulation, may enumerate additional categories of aliens who may obtain permission to work. Using this power, DHS has generally permitted aliens who obtain relief under the Deferred Action for Childhood Arrivals (DACA) program to seek employment in the United States. Aliens who qualify for DACA relief--namely, certain aliens who came to the United States as children, lack lawful immigration status, and have not engaged in activities that render them ineligible for relief--may be permitted to remain in the United States and receive work authorization for renewable two-year periods. [...] This Sidebar briefly examines laws governing the employment of aliens in the United States, including restrictions on federal employment and their application to DACA recipients."
CRS Legal Sidebar, LSB10244
Congressional Research Service: https://crsreports.congress.gov/