Homeless individuals have mortality rates three to six times higher than their housed counterparts and have elevated rates of mental illness, substance abuse, and co-morbidities that increase their need for health services. Data on the utilization of Harris County, Texas' public hospital system by 331 homeless individuals and a random sample of 17,824 domiciled patients were obtained from June 2008 to July 2009. Homeless individuals had increased readmission rates, especially within 30 days of discharge, resulting in significantly higher total annual length of stay. Homeless patients also more frequently utilize public hospitals for mental illness and HIV. Lack of community health services contributes to an increased dependence and preventable over-utilization of public hospital systems. Case management interventions integrating primary and behavioral care into health homes, medical respite programs, and training for health care professionals who provide indigent care will improve health outcomes of this population and reduce costs.