Research suggests that the process of adolescents exploring and developing clarity about their ethnic-racial identity (ERI) is an important developmental competency. However, the extent to which individuals view their ERI as central to their overall self-concept (i.e., ERI centrality) informs the degree to which they choose to explore their ERI, potentially moderating ERI development. Utilizing data from a randomized controlled trial of a school-based intervention focused on increasing adolescents' ERI exploration, the current study examined whether the intervention effect was moderated by adolescents' baseline ERI centrality. Study participants (N = 218; M[subscript age] = 15.02; 49% female; 63% ethnic-racial minority; 28% free/reduced lunch) attended a high school in the southwest United States. Moderation analyses indicated that adolescents' ERI centrality at baseline (1-week pretest) significantly moderated the intervention's effect on Time-2 ERI exploration (12-week posttest). Further analyses of simple slopes revealed that the intervention produced significant increases in Time-2 ERI exploration (relative to attention control) for adolescents with average and higher (+1 SD) levels of ERI centrality at baseline, but not for those with lower levels of ERI centrality at baseline (-1 SD), which suggests ERI centrality may have encouraged participant engagement with the intervention. Sensitivity analyses accounting for baseline to posttest changes in ERI exploration and examining long-term effects of the intervention on exploration provided additional support for the specificity of this moderated intervention effect to the 12-week posttest. Our findings are consistent with notions from social identity theory as well as previous research that suggests that ERI centrality encourages ERI exploration among adolescents.