ABSTRACTThe Therapeutic Education System (TES), an Internet version of the Community Reinforcement Approach plus prize-based motivational incentives, is one of few empirically supported technology-based interventions. To date, however, there has not been a study exploring differences in substance use outcomes or acceptability of TES among racial/ethnic subgroups. This study uses data from a multisite (N = 10) effectiveness study of TES to explore whether race/ethnicity subgroups (White [n = 267], Black/African American [n = 112], and Hispanic/Latino [n = 55])moderate the effect of TES. Generalized linear mixed models were used to test whether abstinence, retention, social functioning, coping, craving, or acceptability differed by racial/ethnic subgroup. Findings demonstrated that race/ethnicity did not moderate the effect of TES versus TAU on abstinence, retention, social functioning, or craving. A three-way interaction (treatment, race/ethnicity, and abstinence status at study entry) showed that TES was associated with greater coping scores among nonabstinent White participants (p = .008) and among abstinent Black participants (p < .001). Acceptability of the TES intervention, although high overall, was significantly different by race/ethnicity subgroup with White participants reporting lower acceptability of TES compared to Black (p = .006) and Hispanic/Latino (p = .008) participants. TES appears to be a good candidate treatment among a diverse population of treatment-seeking individuals with substance use disorders.