This document is a research proposal that aims to analyze and compare the prevalence of serious mental illness among individuals in correctional facilities versus psychiatric care facilities in the United States. It provides background on the history of housing the mentally ill, from the 1800s when rates in prisons were under 1% to present day where rates are estimated to be 15-20% due to deinstitutionalization in the 1960s. It defines serious mental illnesses like schizophrenia, bipolar disorder, and major depression that will be examined. Issues that mentally ill inmates face during incarceration are discussed, like lack of proper treatment environment and increased costs. Screening and assessment procedures used to identify mental illness upon inmate intake are also overviewed. The purpose is to