Idaho Maximum Security Institution (IMSI) is a maximum-security prison located near Kuna, Idaho, United States,[1] one of a cluster of seven detention facilities known as the "South Boise Prison Complex".

IMSI houses Idaho's death row for men and execution chamber.

The IMSI prison was opened in November 1989 to confine Idaho's most violent offenders.

IMSI has restrictive housing beds dedicated to administrative segregation, disciplinary detention and death row.

The remaining beds are allocated for close-custody general population offenders.