What are the differences between Medicare Part A and Medicare Part B?

Medicare Part A is hospital insurance and you get it when you turn 65 automatically. Part B is like a regular insurance policy that you have to pay for, but you aren't eligible to buy it until you are 65. For Medicare Part A to kick in and be the primary during a medical claim, there has to be a qualifying hospitalization (3 overnights), plus a qualifying diagnosis. Part A will carry over and continue coverage in a Skilled Nursing Facility for up to 100 days or for Home Healthcare after hospitalization.