This report from the RAND Corporation shares lessons learned from the redesign of seven university principal preparation programs with their district and state partners under The Wallace Foundation’s University Principal Preparation Initiative (UPPI). The report describes the methods of and findings from the RAND Corporation’s five-year study and discusses three main themes: (1) UPPI teams improved the coherence of the programs; (2) the universities used partnerships and supports to conceptualize and carry out changes to the programs; and (3) partners took the UPPI testbed strategies beyond the UPPI program. This report is primarily intended as a secondary resource for readers who would like more detail about the study’s findings and methods.