What is Medicare? Medicare is health insurance for people 65 or older who meet citizenship or residency requirements. You may get it earlier if you have a disability, End-Stage Renal Disease (ESRD), or ALS (Lou Gehrig's disease). Some people get Medicare automatically. Others have to sign up. Medicare is run by the federal government. It is not the same as Medicaid, which is a separate program run with the states.
Medicare in four parts
- Part A is hospital insurance. It is free for most people.
- Part B covers doctor visits and outpatient care. It has a monthly premium.
- Part C (Medicare Advantage) is a private plan that bundles Parts A and B. Most of these plans also include drug coverage.
- Part D helps pay for prescription drugs.
Parts A and B together are called Original Medicare. Many people add a Medigap policy to Original Medicare to help with out-of-pocket costs. New to this? Start with Turning 65: Start Here, or see what Medicare costs.
The wider landscape
Government-sponsored health coverage in the United States is a patchwork of federal programs, state agencies, and private plans under contract. These pages explain the whole landscape in plain terms — a good starting point whether you're a member, a caregiver, or new to working in the field.
Learn the landscape
Coverage Basics
Medicare, Medicaid, Medicare Advantage, the Marketplace, and CHIP — what each is, who runs it, and who qualifies.
How Programs Are Governed
Who sets the rules, how the rulemaking cycle works, and where to track regulatory change.
Reference tools
Plain-English Glossary
Searchable definitions for the terms members and professionals actually encounter.
State Medicaid Directory
The official program name and agency website for every state and DC.
The Member Journey
How a person moves through enrollment, care, claims, and appeals — start to finish.
The one framework worth remembering
For any coverage program, three questions cut through most of the confusion:
- Who funds it? Federal, state, or a mix — from taxes, premiums, or both.
- Who administers it? A federal agency directly, states within federal rules, or private companies under contract.
- Who delivers the benefits? The government directly, or private insurers and providers on the program's behalf.
Those three questions separate Medicare from Medicaid from Medicare Advantage from the Marketplace. Coverage Basics walks through each program with that lens, and Medicare vs. Medicaid puts the two most-confused programs side by side.
Medicare, program by program
Hospital Insurance
Inpatient hospital, skilled nursing, hospice, and home health — and benefit periods.
Medicaid, the Marketplace & CHIP
Eligibility, Waivers & Long-Term Care
Pathways, waivers, LTSS, dual eligibility, and why it varies by state.
The Health Insurance Marketplace
Metal tiers, premium tax credits, and Special Enrollment Periods.