This study addresses the relative importance of specific 12-step activities to recovery, and how treatment affects participation in those activities. Data were from a clinical trial testing a 12-step facilitation intervention called MAAEZ (Making AA [Alcohol Anonymous] Easier). Participants (N = 508) were recruited at treatment entry. Analyses examined 8 activities measured at baseline, 7 weeks, 6 months, and 12 months. In simultaneous equations, meeting attendance and having a sponsor were the only strong and consistent predictors of abstinence across time points, though other activities (i.e., use of a home group, befriending members, service work, and reading the literature) were significant in some analyses. Treatment involvement had mixed effects on activity participation over time. Contradicting research suggesting that meeting attendance contributes little beyond other 12-step activities, the current results highlight the importance of consistent meeting attendance and sponsorship in recovery. The results suggest a need for enhanced facilitation of key activities even in typical 12-step-oriented treatment.