This retrospective study examines 24-month outcomes for 38 participants with histories of chronic homelessness and hospitalizations in an urban, residential integrated treatment (IT) program and compares characteristics of those who stayed in the program 24 months with those who left within their first year of residence. Informed by an Assertive Community Treatment approach, characterized by outreach (or what might better be referred to as inreach), low staff to consumer ratio, and meeting of basic needs, the residential program emphasized harm reduction and motivational interventions. The longitudinal study design was supplemented with a comparative analysis of treatment completers and noncompleters. There were significant differences between the two groups at baseline in terms of engagement with treatment, alcohol use severity, and mental health diagnosis. Additionally, those who stayed with the program showed significant reductions in alcohol and drug use, significant reduction in hospitalizations, and advances in treatment engagement.