Civic primer
How U.S. public healthcare works
The federal government runs two large health-coverage programs — Medicare and Medicaid — plus the related Children's Health Insurance Program (CHIP). This is a plain-language reference to what each one is, who runs it, what it covers, and who is eligible. Neutral by design; the numbers and rules link to official sources.
The two federal programs
Most government-provided health coverage in the U.S. flows through two programs created in 1965. Both are administered at the federal level by the Centers for Medicare & Medicaid Services (CMS), an agency within the Department of Health and Human Services.
- Medicare — a federal program of health insurance primarily for people 65 and older (and some younger people with disabilities). Eligibility and benefits are set nationally and are the same in every state.
- Medicaid — a needs-based program jointly funded by the federal government and the states and administered by each state. Eligibility and some benefits vary from state to state.
A quick way to keep them apart: Medicare is mostly about age (65+) and is run nationally; Medicaid is about income and need and is run by the states within federal rules. Many people qualify for both.
Medicare
Medicare is organized into four "parts," each covering a different kind of care. In plain terms:
| Part | What it covers |
|---|---|
| Part A — Hospital | Inpatient hospital stays, skilled nursing facility care, hospice, and some home health care. Most people pay no premium because they (or a spouse) paid Medicare payroll taxes while working. |
| Part B — Medical | Doctor visits, outpatient care, preventive services, lab tests, and medical equipment. Paid for with a monthly premium. |
| Part C — Medicare Advantage | An all-in-one alternative offered by private insurers approved by Medicare. Bundles Part A and Part B (usually Part D), often with extra benefits. |
| Part D — Prescription drugs | Outpatient prescription-drug coverage, offered through private plans that follow Medicare's rules. |
Who is eligible
- People 65 or older who are U.S. citizens or long-term legal residents.
- Some people under 65 with qualifying disabilities, generally after a waiting period on Social Security disability benefits.
- People with End-Stage Renal Disease (ESRD) — permanent kidney failure requiring dialysis or a transplant — or with ALS.
Medicaid
Medicaid provides health coverage to people with limited income and resources. It is jointly funded by the federal government and the states, and each state administers its own program within federal rules — so what it's called, exactly who qualifies, and some of what it covers can differ by state.
- Needs-based. Eligibility is determined mainly by income (and sometimes assets), often measured against the federal poverty level.
- Federal + state funded. The federal government matches state spending; states run day-to-day enrollment and delivery.
- Varies by state. Because states administer the program, income thresholds and optional benefits differ.
- ACA expansion. The Affordable Care Act let states expand Medicaid to most low-income adults under 65. Expansion is a state choice, so coverage for low-income adults depends on whether a person's state expanded.
Children in families that earn a little too much for Medicaid may qualify for CHIP, the Children's Health Insurance Program — a related federal-state program that covers children (and in some states, pregnant people) at low or no cost.
How it applies to different people
Which program a person uses depends mostly on age, income, and circumstance. This table is a general guide, not a determination — exact eligibility is set by federal rules and, for Medicaid, by each state.
| Group | Typical coverage |
|---|---|
| Seniors (65+) | Medicare. Those with low income may also qualify for Medicaid ("dual-eligible") to help with costs Medicare doesn't cover. |
| Low-income adults & families | Medicaid, where eligible — broadest in states that adopted the ACA expansion. |
| Children | Medicaid or CHIP, depending on family income; CHIP covers many children just above the Medicaid line. |
| People with disabilities | Medicare (via Social Security disability, after a waiting period) and/or Medicaid, depending on income and situation. |
| Pregnant people | Medicaid and, in many states, CHIP provide pregnancy-related coverage up to higher income limits. |
| Dual-eligibles | People who qualify for both Medicare and Medicaid; Medicaid helps cover premiums, cost-sharing, and services Medicare doesn't (e.g. long-term care). |
Official sources
These are the authoritative government sites. Use them to check eligibility and current rules:
- Medicare.gov — the official Medicare site (enrollment, parts, plans)
- Medicaid.gov — the official Medicaid & CHIP site (eligibility, state programs)
- CMS.gov — the Centers for Medicare & Medicaid Services, which runs both programs
CivicGate is a neutral reference. This page explains how the programs work; see the civics primer for how mandatory spending like Medicare and Medicaid fits into the federal budget.