Prisoners account for a substantial share of the total population infected with HIV, AIDS, hepatitis B, hepatitis C, and tuberculosis. For example, in 1997, individuals released from prison or jail accounted for nearly one-quarter of all people living with HIV or AIDS, almost one-third of people diagnosed with hepatitis C, and more than one-third of those diagnosed with tuberculosis. ^[1]   Virtually all people in prison or jail are at high risk for many chronic and communicable diseases. Individuals in this population, when not incarcerated, are often among the hardest for the health system to identify in part because the criminal justice system and health system rarely collaborate to discuss their shared population. Accordingly, periods of incarceration provide what the National Commission on Correctional Health Care describes as a "window of opportunity" for a variety of preventive, diagnostic, and treatment interventions that stand to benefit not only inmates, but also their families, partners, friends, and communities. ^[2]   , ^[3]