One of the greatest lies from the looney left about Medicare is that seniors are stupid and therefore cannot make choices from all the private Medicare options in the market (there are public options too). The corrollary to that lie is that once seniors make their choice they are forever locked into the clutches of bloodsucking for-profit insurance companies and cannot change their mind. That's another looney left lie about Medicare.
As the Medicare and You booklet (see image from the booklet above; 2014 booklet cover illustrated in upper right corner of image) clearly shows, seniors and other Medicare beneficiaries get "at least one" -- not just one -- chance per year to make changes to their plans.