Medicare is a federal health insurance program primarily for people age 65 and older. It also covers certain individuals under 65 who have received Social Security disability benefits for at least two years, and people of any age diagnosed with End-Stage Renal Disease (ESRD).

The program was signed into law in 1965 and has evolved over time. Major milestones include the creation of Medicare Advantage plans through the Balanced Budget Act of 1997 and the addition of prescription drug coverage (Part D) via the Medicare Modernization Act of 2003.

“Original Medicare” includes two parts: Part A, which covers hospital-related expenses, and Part B, which covers outpatient medical services like doctor visits and preventive care. While these two parts form the foundation of Medicare, they don’t cover everything—there are deductibles, coinsurance, and no cap on out-of-pocket spending. That’s why most people choose to add coverage through either a Medicare Supplement (Medigap) policy or a Medicare Advantage plan, depending on their needs and preferences.