Individuals without stable housing are at increased risk for acute and chronic medical conditions with multiple medical comorbidities. Lack of control over diet and living conditions, precedence given to meeting basic needs over health care, limited opportunities to follow an optimal treatment plan, and mobility coupled with a fragmented health care delivery system consistently increase displaced people’s risk for complications of chronic illness and premature mortality. Because the homeless may not seek or be able to obtain care until their illness is advanced, they often present with more acute, life threatening conditions, e.g., heart attacks, stroke, organ damage secondary to uncontrolled cardiovascular disease and/or diabetes. Chronic health conditions such as hyperglycemia, asthma, and hypertension are exacerbated by stress and exposures associated with homelessness, as well as by delayed or interrupted treatment. In addition, chronic medical conditions common to the general population (such as asthma, chronic obstructive pulmonary disease, diabetes, cardiovascular disease, and chronic diseases of the liver and kidneys) tend to be more prevalent among individuals experiencing homelessness and are typically more severe. Furthermore, psychosocial and societal issues such as discrimination and stigma that impede homeless people’s access to treatment and self-care often increase their risk for medical complications.