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 South Dakota, 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. While federal law outlines the processes for unauthorized immigrants to adjust their status to become lawful permanent residents (LPRs), they remain unauthorized until they successfully obtain a green card. Temporary Protected Status (TPS) beneficiaries, while not having a permanent immigration status, are not considered unauthorized because TPS provides a temporary lawful presence and work authorization. It's important to note that while state laws may address certain aspects of unauthorized immigrants' lives, such as access to education or driver's licenses, immigration enforcement and the adjustment of immigration status are federal matters. An attorney specializing in immigration law can provide guidance on these complex processes and any state-specific considerations.