The Kaiser Family Foundation (KFF) released a brief examining recent changes to Medicare Advantage (MA) plans and trends in MA plan participation, costs, and benefits.  KFF determined that 12 million individuals, or approximately 25 percent of all Medicare beneficiaries, are enrolled in MA plans.  The brief suggests that MA plan beneficiaries will have an average of 24 plans available to them, despite a 13 percent decline of in the total number of MA plans.

From the report:

The Centers for Medicare and Medicaid Services (CMS) recently released information about the Medicare Advantage plans that will be available in 2011. As of September 2010, 11.8 million Medicare beneficiaries, nearly one-quarter of the total Medicare population, are enrolled in Medicare Advantage plan. The Data Spotlight briefly reviews recent change made to the Medicare Advantage program and examines trends in plan participation, premiums, and certain benefits.

Full Report: Medicare Advantage 2011 Data Spotlight (PDF | 1.29 MB)   

Kaiser Family Foundation. (2010). Medicare Advantage 2011 Data Spotlight. Gold, M., Jacobson, G., Damico, A., and Neuman, T.