Objective: This study compared health and social characteristics of two groups of homeless adults in Manhattan—those who were chronically unsheltered and those who were not. Methods: Outreach workers conducted brief, structured interviews with 1,093 unsheltered homeless adults. Respondents were later categorized as being chronically unsheltered on the basis of New York City criteria (sleeping without shelter at least nine of the previous 24 months). Results: The sample had high rates of substance abuse (65%), serious medical issues (42%), and repeated trauma (51%) and low rates of medical insurance (47%) and income entitlements (26%) entitlements. Sixty-seven percent were chronically unsheltered, and these respondents had significantly higher rates on several measures, including military service, incarceration, and mental illness. Conclusions: The sick and aged nature of this population suggests that more aggressive efforts are needed to enroll unsheltered homeless people in income and health benefits and to create adequate housing opportunities with appropriate support services. (Psychiatric Services 60: 978–981, 2009)