To assess the impact of the Patient Protection and Affordable Care Act's () changes in Medicare Advantage () payment rates on the availability of and enrollment in plans.
Secondary data on plan offerings, contract offerings, and enrollment by state and county, in 2010–2011.
We estimated regression models of the change in the number of plans, the number of contracts, and enrollment as a function of quartiles of spending and pre‐ payment generosity. Counties in the lowest quartile of spending are treated most generously by the .
Relative to counties in the highest quartile of spending, the number of plans in counties in the first, second, and third quartiles rose by 12 percent, 7.6 percent, and 5.4 percent, respectively. Counties with more generous payment rates before the lost significantly more plans. We did not find a similar impact on the change in contracts or enrollment.
The ‐induced payment changes reduced the number of plan choices available for Medicare beneficiaries, but they have yet affected enrollment patterns.