The unauthorized or undocumented resident immigrant population is defined as all foreign-born non-citizens who are not legal residents. Most unauthorized residents either entered the United States without inspection or were admitted temporarily and stayed past the date they were required to leave.

Unauthorized residents applying for adjustment to lawful permanent resident (LPR) status under the Immigration and Nationality Act (INA) are unauthorized until they have been granted lawful permanent residence (a green card)—even though they may have been authorized to work. Persons who are beneficiaries of Temporary Protected Status (TPS) are not technically unauthorized.

In Louisiana (LA), as in all states, the definition and treatment of unauthorized or undocumented resident immigrants are primarily governed by federal law, specifically the Immigration and Nationality Act (INA). Unauthorized immigrants are those who have entered the United States without proper inspection or have overstayed their visas. These individuals are not considered legal residents until they adjust their status to Lawful Permanent Resident (LPR), commonly known as obtaining a green card. During the application process for LPR status, they remain unauthorized despite possibly having work authorization. Temporary Protected Status (TPS) beneficiaries, on the other hand, have a temporary lawful status due to conditions in their home countries that prevent safe return, and thus are not considered unauthorized immigrants. It's important to note that while immigration enforcement is a federal matter, state laws may impact unauthorized immigrants in various ways, such as access to education and other state services.