States with more health care spending have better-quality health care: lessons about Medicare.

Based on broad measures of health system quality and performance, states with more total health spending per capita have better-quality care. This fact contrasts with a previous finding that states with higher Medicare spending per enrollee have poorer-quality care. However, quality results from the total funds available and not from Medicare or any single payer. Moreover, Medicare payments are disproportionately high in states that have a disproportionately large social burden and low health care spending overall. These and other vagaries of Medicare spending pose critical challenges to research that depends on Medicare spending to define regional variation in health care.