Favorable Risk Selection in Medicare Advantage: Trends in Mortality and Plan Exits Among Nursing Home Beneficiaries.

The 2003 Medicare Modernization Act (MMA) increased payments to Medicare Advantage plans and instituted a new risk-adjustment payment model to reduce plans' incentives to enroll healthier Medicare beneficiaries and avoid those with higher costs. Whether the MMA reduced risk selection remains debatable. This study uses mortality differences, nursing home utilization, and switch rates to assess whether the MMA successfully decreased risk selection from 2000 to 2012. We found no decrease in the mortality difference or adjusted difference in nursing home use between plan beneficiaries pre- and post the MMA. Among beneficiaries with nursing home use, disenrollment from Medicare Advantage plans declined from 20% to 12%, but it remained 6 times higher than the switch rate from traditional Medicare to Medicare Advantage. These findings suggest that the MMA was not associated with reductions in favorable risk selection, as measured by mortality, nursing home use, and switch rates.