Good management practice has long been seen as critical to improving the performance, quality, and efficiency of healthcare systems. Better hospital management practice has been shown to correlate with improved clinical quality and performance. However, the association between the management practices of healthcare payors, the performance of the healthcare systems they oversee, and the health of their managed populations, has not been explored quantitatively. We collected data for all 152 healthcare payors and 53 million residents in England to explore the relationships between payor management practices and the performance of the healthcare system each payor managed. First, we found that better healthcare payor management practices are associated with improved health system performance in the domains of quality and value for money, and with improvements in the overall health and well-being of the managed population. Second, we found better payor management practice is associated with improvements in specific outcome metrics related to healthcare system effectiveness, safety, and value for money. Finally, we found no association between payor management practices and metrics for patient experience and access. These findings provide the first known quantitative evidence of a link between healthcare payor management practice and health system performance. They may also help both governments and payors themselves understand what healthcare system performance improvements might be possible from improving the management practices of healthcare payors.