This meta-analysis examined school-based intervention research based on functional behavioral assessment (FBA) to determine the effectiveness of key individualized positive behavior support (IPBS) practices in school settings. In all, 83 studies representing 145 participants were included in the meta-analysis. Intervention, maintenance, and generalization effects were measured by computing the percentage of nonoverlapping data points (PND). Overall, FBA-based interventions were found to be equally effective across diverse student populations and educational settings, including inclusive classrooms. In terms of key IPBS practices, results indicated that team decision making during intervention planning led to significantly larger PNDs. Descriptive analysis revealed that there has been an increase in the use of IPBS practices in school-based FBA-based intervention research; however, some deficiencies were noted. Implications and recommendations for future research are discussed. (Contains 2 tables.)