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 Nevada, as in all states, the unauthorized or undocumented resident immigrant population consists of foreign-born individuals who are not legal residents. This includes those who entered the country without proper inspection and those who overstayed their visas. Unauthorized immigrants in Nevada are subject to federal immigration laws, primarily governed by the Immigration and Nationality Act (INA). Under the INA, unauthorized residents may seek to adjust their status to become lawful permanent residents (LPRs), commonly referred to as obtaining a green card. However, until they successfully adjust their status, they remain unauthorized. It's important to note that while unauthorized immigrants may not have legal status, some may have been granted work authorization through various means, such as pending LPR applications or other temporary relief from removal. Additionally, individuals with Temporary Protected Status (TPS) in Nevada are considered to have a lawful status and are not classified as unauthorized, although TPS is a temporary benefit that does not directly lead to LPR status.