Medicare Part C (Medicare + Choice) is a Medicare program that gives beneficiaries more choices among health plans. Everyone who has Parts A and B is eligible with the exception of those who have ESRD (End Stage Renal Disease) and were not signed up with a Medicare + Choice plan at the onset of ESRD. A Medicare + Choice plan is a Medicare managed care plan. The types of Medicare managed care plans are HMO's (Health Maintenance Organizations, PPO's (Preferred Provider Organizations), PSO's (Provider Sponsored Organizations), and PFFS's (Private Fee For Services) plans.