In correctional institutions, segregation units (an area where selected inmates are isolated from the general prison population) often accommodate inmates with serious and persistent mental illness, as well as impulsivity, substance abuse, violence, and other behavioral problems. Psychologists perform work in these units that are crucial to their agency’s mission, specifically risk management and the humanistic goal of saving lives at risk. Psychologists’ work in segregation units distinguishes them as specialists, which requires them to use their unique training and knowledge. This article discusses the individual segregation inmate, the context of segregation and what it exerts on the mental health of the inmates in segregation, the processes of psychologists’ work formed by the interactions between inmates in the context of segregation, and future advancements in the mental health practice in segregation. Overall, segregation is an intensely systemic environment requiring an equally systemic treatment response. Correctional psychologists must continue their work to reduce the impact of segregation through empirically supported prevention and diversion interventions, training programs, and the judicious modification of the location itself. 4 Endnotes