The purpose of this study was to explore the direct and indirect effects of SWPBIS on high school dropout rates. We used structural equation modeling methods to analyze the web of relationships among important high school level outcomes and SWPBIS in a large sample of high schools from 37 states. Results suggest that SWPBIS has statistically significant positive effects on attendance at the high school level and that attendance is a proximal and statistically significant indicator of high school dropout risk. The study did not find significant or consistent direct short-term effects of SWPBIS on dropout rates; however, the results suggest that schools implementing SWPBIS with fidelity for longer periods of time may see greater reductions in dropout rates. Implications for future research, practice, and policy are discussed.