Medicare is a type of individual health insurance that is available to Americans and other qualified people depending on factors like age, disability, or a specific medical condition. Medicare coverage consists of Medicare Advantage (Part C) and Part D prescription drug coverage, both of which are provided by commercial insurance firms, as well as Original Medicare Parts A and B (supplied by the federal government). Private insurance providers also provide Medicare supplement insurance (Medigap) policies, which assist in covering some out-of-pocket costs that Medicare Parts A and B do not cover.