Medicare Parts A, B, C, and D Explained

Medicare is easier to understand when you separate two questions: what does each part cover? and how do you want to receive that coverage?

The short versionOriginal Medicare is Part A plus Part B. You may add a separate Part D drug plan and, if eligible, a Medigap policy. Medicare Advantage — also called Part C — is a private-plan alternative that provides Part A and Part B benefits and usually includes Part D.

Part A: Hospital Insurance

Part A helps cover inpatient hospital care, skilled nursing facility care, hospice care, and some home health care. It is not a blanket label for every service you receive inside a hospital; whether a stay is inpatient or outpatient can affect which part pays.

Most people do not pay a monthly Part A premium because they or a spouse paid Medicare taxes long enough while working. Medicare describes this as premium-free Part A.

Part B: Medical Insurance

Part B helps cover services from doctors and other health care providers, outpatient care, durable medical equipment, many preventive services, and certain home health services.

In 2026, the standard Part B premium is $202.90 per month, and the annual Part B deductible is $283. Some people pay more because of income.

Part D: Prescription Drug Coverage

Part D helps cover prescription drugs, including many recommended vaccines. You can get it through a separate Medicare drug plan alongside Original Medicare, or through a Medicare Advantage plan that includes drug coverage.

Part D plans are offered by private insurance companies that follow Medicare rules. Formularies, networks, premiums, and covered drugs can differ by plan, so the letter “D” does not mean every plan is interchangeable.

Part C: Medicare Advantage

Medicare Advantage is another way to receive Medicare benefits. These plans are offered by private companies approved by Medicare. They provide your Part A and Part B benefits and usually include Part D drug coverage.

Plans may use provider networks, prior authorization, or service-area rules. Benefits and out-of-pocket costs can vary by plan and location. A plan comparison has to use the plans actually available in your ZIP code — not a national “best plan” list.

The two main paths

Original Medicare	Medicare Advantage
Includes Part A and Part B.	Private-plan alternative that provides Part A and Part B benefits.
You may add a separate Part D drug plan.	Most plans include Part D, but check the specific plan.
You can use any doctor or hospital that takes Medicare anywhere in the U.S.	Plans may use networks and service areas; check whether providers are in-network.
You may buy Medigap to help with your share of Original Medicare costs, subject to eligibility and enrollment rules.	Medigap does not work with Medicare Advantage.

Where Medigap fits

Medigap is Medicare Supplement Insurance sold by private companies. It can help pay some of your share of costs in Original Medicare. It is not Part C and it is not a substitute for Part B. Medigap policies are standardized by letter in most states, but availability and pricing still require a state-specific check.

Do not choose a path from a television commercial alone. Check your doctors, prescriptions, pharmacies, travel needs, total expected costs, and the rules for changing coverage later.

2026 numbers to keep separate

$202.90: the standard monthly Part B premium.
$283: the annual Part B deductible.
$1,736: the Part A inpatient hospital deductible for each benefit period.
$0 for most people: the Part A monthly premium when they qualify for premium-free Part A.

These figures describe Original Medicare costs; they do not tell you the premium, deductible, copayments, network, or maximum out-of-pocket amount for a specific Medicare Advantage or Part D plan.

A better order for comparing coverage

Confirm your Part A and Part B enrollment timing.
List your doctors, hospitals, prescriptions, and preferred pharmacies.
Decide whether nationwide Original Medicare access or a local plan structure better matches your needs.
Compare total costs, not just the monthly premium.
Use Medicare’s official Plan Compare tool for the plans available where you live.

Official sources used

Sources last checked Aug. 28, 2026. Plan availability, premiums, networks, and benefits can change. Use Medicare.gov or 1-800-MEDICARE for current, individualized information.