This study grouped treatment-seeking individuals (n = 1825) by common patterns of 12-step attendance using 5 waves of data (75% interviewed Year 9) to isolate unique characteristics and use-related outcomes distinguishing each class profile. The ‘high’ class reported the highest attendance and abstention. The ‘descending’ class reported high baseline alcohol severity, long treatment episodes, and high initial attendance and abstinence, but by Year 5, their attendance and abstinence dropped. The ‘early-drop’ class, which started with high attendance and abstinence but with low problem severity, reported no attendance after Year 1. The ‘rising’ class, with fairly high alcohol and psychiatric severity throughout, reported initially low attendance, followed by increasing attendance paralleling their abstention. Last, the ‘low’ and ‘no’ classes, which reported low problem severity and very low/no attendance, had the lowest abstention. Female gender and high alcohol severity predicted attendance all years. Consistent with a sustained benefit for 12-step exposure, abstinence patterns aligned much like attendance profiles.