Service use and 2-year treatment outcomes were compared between chronically homelessness clients receiving comprehensive housing and healthcare services through the federal Collaborative Initiative on Chronic Homelessness (CICH) program (n = 281) a sample of similarly chronically homeless individuals receiving usual care (n = 104) in the same 5 communities. CICH clients were housed an average of 23 of 90 days (52%) more than comparison group subjects averaging over all assessments over a 2-year follow-up period. CICH clients were significantly more likely to report having a usual mental health/substance abuse treater (55% vs. 23%) or a primary case manager (26% vs. 9%) and to receive community case management visits (64% vs. 14%). They reported receiving more outpatient visits for medical (2.3 vs. 1.7), mental health (2.8 vs. 1.0), substance abuse treatment (6.4 vs. 3.6), and all healthcare services (11.6 vs. 6.1) than comparison subjects. Total quarterly healthcare costs were significantly higher for CICH clients than comparison subjects ($4,544 vs. $3,326) due to increased use of outpatient mental health and substance abuse services. Although CICH clients were also more likely to receive public assistance income (80% vs. 75%), and to have a mental health/substance provider at all, they expressed slightly less satisfaction with their primary mental health/substance abuse provider (satisfaction score of 5.0 vs. 5.4). No significant differences were found between the groups on measures of substance use, community adjustment, or health status. These findings suggest that access to a well funded, comprehensive array of permanent housing, intensive case management, and healthcare services is associated with improved housing outcomes, but not substance use, health status or community adjustment outcomes, among chronically homeless adults.