This longitudinal health services study (N = 733) (1) examines the impact of services received on 6-month outcomes, and (2) compares day-hospital to residential programs on services received. Services were measured at 2, 4, and 8 weeks postbaseline using a version of the Treatment Services Review. Higher odds of total sobriety at 6 months were associated with greater participation in (a) extracurricular (but not curricular) 12-step meetings, (b) sober recreational events, and (c) educational sessions. Program effects also emerged. Unexpectedly, extracurricular 12-step meeting attendance and the odds of having a sponsor were lower among residential (vs. day hospital) participants through 4 weeks, despite higher participation in curricular 12-step meetings among residential participants at 2 weeks. Still, residential participants reported higher involvement in sober recreation and informal peer socialization across most analyses. Findings suggest that residential and day-hospital programs might maximize outcomes by facilitating optional 12-step involvement and sober recreation, respectively.