The American Prospect: In 46 states, once you choose Medicare Advantage at 65, you can almost never leave. “…Sixty-five million seniors are in Medicare open enrollment from October 15 until December 7. Nearly 32 million of those patients are enrolled in Medicare Advantage, a set of privately run plans that have come under fire for denying treatment and overbilling the government. Medicare Advantage patients theoretically have the option to return to traditional Medicare. But in 46 states, it is nearly impossible for those people to do so without exposing themselves to great financial risk. Traditional Medicare has no out-of-pocket cap and covers 80 percent of medical expenses. Unlike Medicare Advantage plans, in traditional Medicare, seniors can choose whatever provider they want, and coverage limitations are far less stringent. Consequently, there’s a huge upside to going with traditional Medicare, and the downside is mitigated by the purchase of a Medigap plan, which covers the other 20 percent that Medicare doesn’t pay. While this coverage is more expensive than most Medicare Advantage plans, nearly everybody in their old age would like to be able to choose their doctor and their hospitals, and everybody would want the security of knowing that they won’t be denied critical treatments. In 46 states, however, Medigap plans are allowed to engage in what’s called underwriting, or medical health screening, after seniors have already chosen a Medicare Advantage plan at age 65…”