The purpose of this research (N = 160) was to describe and compare substance abuse treatment in two programs under managed care: one residential (RT) and one outpatient (OP). Clients in both settings improved significantly from before to after treatment in relation to substance use and quality of life. However, intensity of treatment (hours of care/week) was much greater in RT and days of sobriety were significantly higher after treatment in RT than in OP (p = .04). Intensity was negatively related to incidents of substance use during treatment (SUdT), which predicted substance use after treatment; SUdT averaged.2 for RT, and 1.6 for OP (p = .0001). Importantly, treatment was completed by 74 patients (over 90%) from RT, with 8 dropping out, and 53 (almost 70%) of those in OP completed treatment while 25 dropped out. Intensity, as seen in the RT program, rather than duration, was more effective in substance use reduction and treatment completion. Copyright © Informa Healthcare.