 Third, people who live in two different geographical areas of the country at different times of the year (mostly so-called snowbirds) find it difficult to live with the geographic restrictions of most public Part C plans.Fourth, sicker people and people with higher medical expenditures are more likely to switch from Medicare Advantage plans to Medicare Parts A and B only, a statistic primarily driven by people on Medicaid in custodial care at nursing homes; people on both Medicare and Medicaid no longer have need of any Medicare supplement, either a public Part C plan or a private Medigap or group retirement plan.The Part C risk adjusted payments to Medicare Advantage plans are designed to limit this churn between types of Medicare (managed vs. FFS), but it is unclear how effective that equalization program is.