A central question in the US debate over privatized Medicare is whether increased government contributions to private plans generate lower premiums for consumers or higher profits for producers. This research finds that insurance companies pass through 45% of higher payments in lower premiums and an additional 9% in more generous benefits for those who enroll in Medicare Advantage. Since the findings also suggest that the less than full pass-through is a result of insurer market power, efforts to make markets more competitive may be key to increasing the pass-through to consumers.