 In other words, the research on Medicare HMOs is the same as the research on all HMOs.In the case of Medicare Part C, it is difficult to generalize the results of research either way across all plans participating in the program because performance on quality and access metrics varies widely across the types of Medicare Advantage plans and among the hundreds of sponsors of Medicare Advantage plans and those plans' thousands of providers.That is why having choice between types of Medicare and many choices within Part C is so important.