Medicare Advantage, Explained

Medicare Advantage is Part C of Medicare. It is not a separate program and it is not a supplement — it is a different delivery route for the same entitlement. You stay in Medicare. Medicare pays a private insurer a set amount each month to take on your care, and that insurer administers your benefits under rules Medicare sets and audits.

Three things follow from that structure, and they are the three most useful facts about Part C:

• The plan must cover everything Original Medicare covers. Every service Part A and Part B cover, a Medicare Advantage plan must cover too. Hospice care is the standing exception — it stays under Part A even while you are in an Advantage plan.
• You keep paying your Part B premium. Enrolling in Part C does not replace it. Your Part B premium is $202.90 a month in 2026 for most people, higher for higher incomes, and you owe it whether your care comes through Original Medicare or through a plan. Any premium a plan charges is on top of it.
• You cannot pair it with a Medigap policy. Medicare Supplement insurance exists to fill Original Medicare's gaps. It does not work alongside Part C, and it is generally against the law for someone to sell you one while you are enrolled in an Advantage plan. These are two different roads, not two pieces of one plan — see how Medigap plans work.

What differs between plans — what each one charges you per visit, which doctors it contracts with, what it covers beyond A and B — is set plan by plan. Those specifics live in the plan's own Summary of Benefits and Evidence of Coverage, and on Medicare's own plan finder at Medicare.gov. This page explains the machinery; the plan's documents are where its numbers are.

The letters after a plan's name describe how you are allowed to use it. This is the part worth understanding before anything else, because it governs whether your own doctor is reachable.

• HMO. Care comes from the plan's network. Outside it, the plan generally pays nothing — the standing exceptions are emergency care, urgently needed care, and out-of-area dialysis, which are protected by rule. Most HMOs ask you to name a primary care doctor and to get a referral before seeing a specialist.
• HMO-POS. An HMO with a point-of-service option: some defined out-of-network care is allowed, at a higher share of the cost. Which services, and how much more, varies.
• PPO. Both in-network and out-of-network care are covered, with out-of-network costing you more. Referrals are typically not required. A PPO trades money for flexibility.
• PFFS. A private fee-for-service plan sets its own payment terms, and a provider decides whether to accept those terms — potentially visit by visit. A provider who treated you last month is not obliged to next month. Confirm acceptance before each appointment.
• SNP. A Special Needs Plan restricted to a defined group: people who also have Medicaid, people with a qualifying chronic condition, or people living in an institution. If you do not belong to the group, you cannot enroll; if you do, the plan is built around that population's care.

None of these is better than the others in the abstract. They are different bargains between cost and freedom of access, and which bargain suits you depends on facts about your own life — your doctors, your conditions, how much you travel.

Every Medicare Advantage plan must cap what you can be charged for in-network Part A and Part B services in a calendar year. Once you hit that cap, the plan pays the full cost of covered in-network care for the rest of the year.

The federal ceiling on that cap is $9,250 for in-network care in 2026 for most plans. That is a maximum, not a typical figure — plans routinely set theirs lower, and a plan's own cap is one of the few numbers genuinely worth comparing. Note also what the cap does not include: your Part B premium, and generally your prescription drug costs, which run on Part D's separate $2,100 cap.

Here is why this matters more than it first appears. Original Medicare has no out-of-pocket maximum at all. Part A and Part B pay their shares — after a $1,736 deductible per benefit period on the hospital side, and 20% coinsurance with no ceiling on the medical side — and the remainder is yours, without limit. A long illness in Original Medicare with nothing filling the gaps has no upper bound.

That is the structural trade. Part C caps your in-network exposure and constrains where you can go. Original Medicare leaves you free to see any provider who accepts Medicare and leaves your exposure uncapped — which is precisely the gap a Medigap policy is bought to close. Comparing the two honestly means comparing Part C against Original Medicare plus whatever you would pair with it, not against bare Original Medicare — which is what the Medigap hub is for.

In Original Medicare, you may see any provider in the country who accepts Medicare, and prior authorization is rare. Medicare Advantage works differently, and the differences are administrative rather than clinical — which makes them easy to underestimate until you need care.

Networks are local and they change. A plan contracts with providers in a service area, and those contracts turn over. A doctor in network this year may not be next year, and a plan may change its network mid-year. Check your own doctors and your own hospital against the plan's current directory before enrolling, and check again each fall.

Prior authorization is common in Part C. For certain services the plan must approve the care before it will pay. If the plan denies it, you have appeal rights on a defined timetable, and those rights are real — but exercising them takes time you may not have wanted to spend.

Travel is a network question. An HMO built around one county behaves very differently for someone who spends half the year elsewhere. Emergency and urgently needed care are covered wherever you are; routine care generally is not.

The plan can change yearly. Each September a plan sends an Annual Notice of Change setting out what is different for January — costs, network, drug list. It is the single most important piece of mail Medicare households receive and the most commonly discarded. Our ANOC explainer walks through how to read one.

This is the decision most people are actually trying to make, and it does not have a general answer. It has a personal one, and it turns on a small number of honest questions.

Where do you want the money to go? A Medigap policy charges a monthly premium and, depending on the letter, leaves you with very little to pay when you use care. A Medicare Advantage plan generally charges less up front and more at the point of service, up to its cap. One is predictable and paid monthly; the other is cheaper monthly and variable when you need it.

How much does provider freedom matter? Original Medicare with a Medigap plan works with any provider in the country who accepts Medicare, with no networks and no referrals. Part C works within a network. If you have a specialist you will not give up, or you split the year between two states, that is often the deciding fact.

And the question people find out about too late: can you change your mind later? Switching from Original Medicare into a Medicare Advantage plan is straightforward during an enrollment window. Coming back the other way is not symmetrical. You can return to Original Medicare during a window — but buying a Medigap policy to go with it may require medical underwriting, and an insurer may charge more or decline you outright based on your health.

There are protected exceptions, and the enrollment windows page sets them out in full. Your one-time Medigap open enrollment period — six months beginning when you are 65 or older and enrolled in Part B — is guaranteed issue. So are certain trial rights, including the first year in an Advantage plan after joining at 65. A few states go further and give residents broader rights to buy Medigap later. But outside those protections, the door back can be conditional on your health, and health is the thing that changes.

Nobody should hear that as a reason to avoid Part C. Millions of people choose it deliberately and are well served. It is a reason to make the decision with the return trip in view rather than discovering it afterwards — and a reason to check your own state's rules, because they vary.

Whatever you choose, these are the checks that separate a good decision from a lucky one. They take an afternoon.

1. Your doctors. Look up each one in the plan's current directory, and call the office to confirm — directories go stale. Ask about the hospital you would want too.
2. Your prescriptions. List each drug and its dose, then check it against the plan's formulary: what tier it sits on, and whether prior authorization, step therapy or a quantity limit applies. A plan's premium tells you nothing about how it treats your particular list.
3. The plan's own out-of-pocket maximum, not the federal ceiling — and what it excludes.
4. The rules for care away from home, if you travel or spend part of the year elsewhere.
5. Your state's Medigap rules, if there is any chance you would want to come back to Original Medicare later. This is the check almost nobody makes, and the one with the longest shadow.
6. Which window you are actually in, and what it does and does not let you do — the enrollment periods page covers all of them.

Medicare's own plan finder at Medicare.gov compares every plan available where you live — including plans we do not offer — and 1-800-MEDICARE is available 24 hours a day. Your State Health Insurance Assistance Program offers free, unbiased counseling with nothing to sell.

If you would rather talk it through with a licensed agent, our plan match quiz is a starting point, and you can ask for a callback. No pressure and no obligation — and if the honest answer is that you should stay where you are, that is the answer you will get.