The job of the school principal has become much more complex and demanding over the past several decades. Many university-based principal preparation programs--which prepare the majority of school principals--have struggled with how to make the fundamental changes needed to prepare principals for today's schools. To test a path forward, The Wallace Foundation provided grants to seven universities and their partners to redesign their principal preparation programs in line with research-supported practices. This targeted report shares findings from the RAND Corporation's five-year study of The Wallace Foundation's University Principal Preparation Initiative (UPPI), with an emphasis on findings for state policymakers. [For "District Partnerships with University Principal Preparation Programs: A Summary of Findings for School District Leaders. RAND Principal Preparation Series. Volume 3, Part 4. Research Report. RR-A413-6," see ED621351.]