Immigrants with or without documents can travel freely by air within the United States.
The Transportation Security Administration (TSA) is the agency of the Department of Homeland Security (DHS), in charge of managing security systems at airports, railways and other means of transportation. To board a domestic flight in the United States, one of the most important documents travelers must carry are identification documents.
The TSA accepts various types of valid identifications so that citizens, tourists or immigrants can travel within the territory. For example, legal permanent residents (LPR) can use their Green Card as identification and tourists can use passports issued by the governments of their countries of origin.
In addition, authorized workers can use their Employment Authorization Card, issued by the Citizenship and Immigration Services.
In the case of undocumented immigrants, there are various identifications that they can use to travel by air in the United States. For example, state driver's licenses or a valid foreign passport are valid identifications.
It should be noted that, as of May 3, 2023, the only state licenses that will be valid for air travel within the United States must have the REAL ID inscribed.
See the full list of IDs for domestic travel: https://www.tsa.gov/travel/security-screening/identification