Most treatment programs recommend clients attend 12-step groups, but many drop out posttreatment. The effectiveness of Making Alcoholics Anonymous [AA] Easier (MAAEZ ), a manual-guided intervention designed to help clients connect with individuals encountered in AA, was tested using an "OFF/ON" design (n = 508). MAAEZ effectiveness was determined by comparing abstinence rates of participants recruited during ON and OFF conditions and by studying the effect of the number of MAAEZ sessions attended. At 12 months, more clients in the ON condition (vs. OFF) reported past 30-day abstinence from alcohol (p = .012), drugs (p = .009), and both alcohol and drugs (p = .045). In multivariate analyses, ON condition participants had significantly increased odds of abstinence from alcohol (odds ratio [OR] = 1.85) and from drugs (OR = 2.21); abstinence odds also increased significantly for each additional MAAEZ session received. MAAEZ appeared especially effective for those with more prior AA exposure, severe psychiatric problems, and atheists/agnostics. MAAEZ represents an evidence-based intervention that is easily implemented in existing treatment programs.