Medicare is a complex and evolving program. This section provides a basic introduction to this health insurance program for individuals 65 and older and people with certain disabilities, with a look into the different parts of the program. You’ll learn how Medicare can be administered publicly (Original Medicare) or privately (Medicare Advantage) and explore program eligibility rules for individuals due to age or disability, including coverage for individuals with ALS and End-Stage Renal Disease. We’ll also review the roles of the Social Security Administration and the Centers for Medicare & Medicaid Services, and see how the Medicare and Medicaid programs can work together.