The purpose of Project 25 is to investigate whether providing permanent housing with intensive individualized support, coupled with an identified, "Medical Home," can realize a significant reduction in the use and cost of public services. This study focuses on those individuals who were among the most frequent users of public services in the San Diego metropolitan area, such as emergency rooms, jails, and hospitals. It was based on the "Housing First" approach, which embraces the concept that secure housing is the first step and essential to stabilizing the personal and financial lives of individuals