This is the eighth in a series of Research-to-Impact briefs by Chapin Hall at the University of Chicago to understand and address youth homelessness. This brief presents the results of a literature review conducted to determine what evidence exists on the effectiveness of programs and practices to prevent youth homelessness and improve various outcomes. The researchers selected 62 studies involving youth homelessness, which evaluated 51 programs, to develop an initial evidence base. This brief outlines the six key findings from this systematic review and the researchers recommendations to expand the evidence base for youth homelessness interventions. These include: 1. A small evidence base shows that youth homeless is preventable; 2. Rental assistance and supportive housing programs show promising results; 3. Most evaluations focus on interventions that address well-being and risk behaviors and show positive results; 4. Family-based interventions show positive results for behavioral health, but more evidence is needed; 5. There is little evidence on interventions to help youth experiencing homelessness achieve better employment outcomes; and 6. There is an alarming mismatch between investments in interventions and their evaluation. (author abstract modified)