Given established links between social-emotional skills and academic achievement, there is growing support for implementing universal social/behavioral interventions in early schooling (Jones & Bouffard, 2012). Advocates have been particularly interested in implementing such programming in low income urban schools where students are likely to start school with lower levels of social-emotional and academic skills than their more affluent peers (Jones & Bouffard, 2012; Raver, 2002). There is inconsistent evidence, however, that such programs improve students’ academic achievement over and above typical educational practice (SRCDC, 2010). One possible constraint to understanding mixed evidence about intervention efficacy is the limited information on how program effects differ across school settings. It could be that universal social/behavioral programs are highly effective in some types of schools and less so in others, thus confounding overall understanding of intervention efficacy. Moreover, although some work has considered how demographic characteristics–like school poverty–differentiate social/behavioral program impacts on student outcomes, fewer studies have examined the moderating role of the school-level social processes (e.g., social norms, relationships) within which interventions are typically embedded. A prevention research perspective suggests that schools with the poorest climates have the most to gain from school-based interventions that explicitly target social interactions (e.g., Cicchetti & Aber, 1998; Van Lier et al., 2004). Contrasting work argues that social/behavioral programs will be most effective for improving student outcomes in settings where extant norms already support positive academic and social-behavioral development (Aber et al., 1998; Hughes et al., 2005). The current study is one of the first to consider the role of school climate in understanding moderated impacts of social/behavioral interventions on student achievement, attention, and behaviors. The major lesson from this work is that context matters. Across student outcomes, program impacts on achievement were generally larger, and sometimes driven by, schools that had less leadership, accountability and safety/respect prior to implementation of the intervention. Perhaps the biggest lesson from this study is for policymakers, who are currently engaged in distributing funding to expand and implement social/behavioral interventions in a variety of settings across the country.