The importance of Medicare simply can't be overstated. According to data from Avalere Health, it's the program responsible for ensuring that 56 million Americans receive medical care this year. The vast majority of these 56 million people are senior citizens aged 65 and over.

Though Social Security usually garners most of the attention since it provides a tangible monthly benefit to seniors, within a few generations Medicare will actually be paying out more in lifetime benefits than Social Security, at least according to an analysis from the Urban Institute. Without Medicare as a foundation to cover a good chunk of the growing medical costs seniors face during retirement, many seniors would likely be in financial trouble.