Medicare is the U.S. government health insurance program primarily serving people aged 65 and older.
Created by amendments to the Social Security Act in 1965, Medicare initially provided hospital and medical coverage for older Americans. It later expanded to cover certain younger people with disabilities and people with End-Stage Renal Disease or amyotrophic lateral sclerosis, commonly called ALS.
Original Medicare has two core parts: Part A, hospital insurance, and Part B, medical insurance. Beneficiaries may instead choose Medicare Advantage, Part C, through private plans that contract with Medicare. Part D provides prescription-drug coverage through private plans.
Medicare is often confused with Medicaid. Medicaid is a joint federal-state program generally based on limited income and other eligibility rules, while Medicare is principally age-based or linked to qualifying disability or medical conditions. Social Security provides income benefits, not the health insurance itself, and TRICARE primarily serves military-connected beneficiaries.