Our interest in editing this special issue stemmed from our experiences researching homelessness alleviation projects in Chicago including the Chicago Housing for Health Partnership (CHHP) and Chicago’s city-wide Plan to End Homelessness. CHHP provided homeless individuals with a quick path to permanent, supportive housing upon release from a hospital for chronic physical illness. With an experimental design, it followed those provided with the housing and compared their outcomes to those provided with “usual care”—a referral to a shelter. The Chicago Plan to End Homelessness implemented a Housing-First strategy, creating new programs to move people who were homeless quickly into permanent housing. It also increased allocations of funding for supportive housing. (author abstract)