Guides › Medicare basics

Medicare Parts A, B, C and D, explained simply

Last checked October 5, 2026 against the official rules. Sources are listed at the end.

The short answer

Part A is hospital coverage. Part B covers doctors and outpatient care. Together they're called Original Medicare. Part D covers prescription drugs. Part C, called Medicare Advantage, is a private plan you can pick instead of Original Medicare. Medigap is extra insurance that pays most of what Original Medicare doesn't.

The whole picture in one table

Part	What it covers	Who runs it	What it costs in 2026
Part A Hospital	Hospital stays, skilled nursing after a hospital stay, hospice, some home health care	The government	Free for most people. $1,736 deductible per hospital stay (once per "benefit period")
Part B Medical	Doctor visits, tests, outpatient care, preventive care, medical equipment	The government	$202.90 a month (more with a high income). $283 yearly deductible, then you usually pay 20%
Part D Drugs	Prescription drugs	Private insurance companies, approved by Medicare	Varies by plan. Your yearly out-of-pocket drug costs are capped at $2,100
Part C Medicare Advantage	Everything in A and B, usually D, often some dental, vision and hearing	Private insurance companies, approved by Medicare	Varies by plan, often little or nothing beyond Part B. Has a yearly limit on what you pay

Part A: the hospital

Part A pays when you're admitted to a hospital, for a short stay in a skilled nursing facility afterward, and for hospice care.

Most people pay nothing for it each month, because they or their spouse worked and paid Medicare taxes for about 10 years. If you didn't, you can buy it ($311 or $565 a month in 2026, depending on how long you worked).

It isn't completely free when you use it. You pay a $1,736 deductible for a hospital stay, then nothing for the first 60 days. A longer stay costs $434 a day for days 61 to 90. If you go back into the hospital within 60 days of leaving, it counts as the same stay, so you don't owe the deductible again.

Part B: doctors and everything else

Part B covers what happens outside a hospital stay: doctor visits, lab tests, X-rays, outpatient surgery, flu shots and screenings, wheelchairs and walkers.

Almost everyone pays a monthly price for it: $202.90 in 2026, taken out of your Social Security check once that starts. People with higher incomes pay more (see lowering your premium after you retire). After a $283 yearly deductible, you usually pay 20% of each bill, with no yearly limit. That open-ended 20% is why most people add Medigap or choose Medicare Advantage.

Original Medicare = Part A + Part B

When people say "Original Medicare" or "Traditional Medicare," they mean Parts A and B together. You can see any doctor or hospital in the country that takes Medicare, with no referrals needed. It doesn't cover most prescriptions, dental, vision, hearing aids or long-term care.

Part D: prescription drugs

Part D is drug coverage you buy from a private insurance company. Each plan has its own price and its own list of covered drugs, so compare plans using your actual prescriptions at medicare.gov/plan-compare.

Starting in 2025, there's a yearly cap on what you pay for covered drugs. In 2026 it's $2,100.

If you don't have other good drug coverage, sign up for Part D when you first get Medicare. Waiting leads to a penalty for life (see late penalties).

Part C: Medicare Advantage

Medicare Advantage is a private plan you can choose instead of Original Medicare. It still covers everything Parts A and B do, and most plans include drug coverage too. You still pay your Part B price.

The trade-offs:

Lower monthly cost. Many plans cost nothing beyond Part B, and many add some dental, vision and hearing coverage.
A network of doctors. You usually need to use the plan's doctors and hospitals, often only near home, and may need approval before some care.
A yearly limit on what you pay out of pocket, unlike Original Medicare by itself.

Medigap: filling the gaps in Original Medicare

Medigap, also called Medicare Supplement Insurance, is extra insurance from a private company that pays most of what Original Medicare leaves you owing, like the 20% for Part B and the hospital deductible. It isn't a "part" of Medicare.

Plans are named with letters, like Plan G and Plan N. Plans with the same letter cover the same things, whatever company sells them. (Massachusetts, Minnesota and Wisconsin use their own versions.)
It only works with Original Medicare. You can't have both Medigap and Medicare Advantage.
It doesn't cover drugs, so pair it with a Part D plan.
Your best time to buy it is the 6 months starting the first month you have Part B and are 65 or older. During those months insurers can't turn you down or charge more because of your health. In most states, that protection ends after those 6 months.

So what do most people end up with?

One of two combinations:

Original Medicare + Medigap + Part D. Higher monthly cost, low and predictable bills, any doctor in the country.
Medicare Advantage (usually with drugs built in). Lower monthly cost, a network of doctors, and costs that depend on the care you use.

Which one fits depends on your doctors, your health, how much you travel and your budget. In most states it's hard to switch from Advantage to Medigap later, because insurers can then turn you down or charge more because of your health. There's one safety net: if you join Medicare Advantage when you first get Medicare, you can switch back to Original Medicare within the first 12 months and still buy Medigap with no health questions.

See when to sign up for each part

Enter your birthday and your health coverage. We'll show when to sign up for Parts A, B and D, and when coverage starts.

Check my dates

Sources

This guide explains the general rules. It isn't legal, tax or insurance advice, and your situation may differ. Settled Years doesn't sell insurance or take commissions.