This report identifies six community-wide approaches to preventing homelessness, three focused on families, two focused on people with serious mental illness, and one focused on youth. It describes four elements common to successful programs: (1) the ability to target people seriously at risk of homelessness; (2) the motivation to invest resources for prevention; (3) mechanisms for maximizing resources by collaborating with non-housing agencies such as child welfare and mental health; and (4) leadership that sets goals, develops strategies, and uses data to track progress, provide feedback, and support improvements.