Medicare is a health insurance program in the United States for people aged 65 and older, as well as those with specific disabilities or end-stage kidney failure. The coverage has expanded over the years to include more people. Medicare has different parts, and it’s important to understand how they work together. Currently, over 60 million people have Medicare coverage. While Part A and Part B cover most expenses, additional policies can be purchased to fill in any gaps not covered by Original Medicare.