Objective: The purpose of this study was to assess the impact of a local initiative, Project H3, which used housing first, harm reduction, and peer support models to provide housing for 47 homeless people who were medically vulnerable. Method: Comparisons of interviews with participants who were housed at the day of their move-in, and 6-months and 12-months after their move-in, were conducted. Results: Ninety-eight percent of the participants remained in housing after 12 months. Individuals who were housed reported significant increases in their access to and utilization of planned health care services and quality of life, and reductions in their involvement in the criminal justice system. Conclusion and Implications for Practice: Housing first, harm reduction, and peer support models demonstrate effectiveness in decreasing substance use and improving the quality of life of people who are homeless over time.