Sobriety, treatment compliance and celibacy have traditionally been behavioral requirements for housing persons who are homeless, regardless of the circumstances leading to loss of home. This remnant of the British Poor Laws is based on the premise that personal and behavioral flaws lead to housing loss and must be remediated before a person can live in permanent housing. A recent approach has reversed this logic and predicates the ability to change based on first providing stable and long-term housing. Termed “housing first,” it is both a housing philosophy or paradigm that everyone deserves a home of their own, regardless of personal circumstances, prior to engaging in any rehabilitative efforts, it also describes specific program models. A review of the research indicates that the success of “housing first” relies more on political support than wide-spread scientific evidence of “best practices”. This report examines the development and scientific evidence for “housing first” programs in North America and suggests that future housing first research examine modifications necessary for distinct geographies and groups of homeless persons.