People join Medicare Advantage plans for a variety or reasons, but the primary two reasons are cost savings and protection. The former head of Medicare, Mark McClellan, MD, recently stated that people save an average of $86 a month (about $1,000 a year) by enrolling in a Part C plan. In addition, many Part C plans protect Medicare recipients against the potentially unlimited out-of-pocket medical costs associated with Original Medicare, by having an annual cap on out-of-pocket expenses.