What Is Medicare Part C?
Medicare Part C is also called Medicare Advantage. It is a way to get your Medicare benefits from a private insurance company instead of straight from the government. Every plan must cover what Part A (hospital) and Part B (medical) cover. Hospice care is the one exception — Original Medicare pays for that, even while you are in a Part C plan. Most plans also include Part D drug coverage. Many add dental, vision, and hearing benefits. And many charge no monthly premium beyond the Part B premium you already pay. In return, you follow the plan’s rules. You use its network of doctors. Some care needs the plan’s OK first. And switching back to Original Medicare later can be harder than the ads let on. This page covers both sides — including the trade-offs the ads skip.
Original Medicare
- Run by the federal government
- Any doctor that accepts Medicare
- No yearly cap on your share of medical costs
- Add Medigap and Part D separately
Medicare Advantage (Part C)
- Run by private insurance companies
- Plan network of doctors and hospitals
- Yearly cap on in-network medical costs
- Drug coverage and extras usually built in
How Medicare Part C works
“Part C” and “Medicare Advantage” mean the same thing. Part C is the name in the Medicare law. Medicare Advantage is the name on the brochures.
When you join one of these plans, you are still in Medicare. You keep Part A and Part B, and you keep paying your Part B premium. What changes is who runs your coverage. Medicare pays the private plan a set amount each month. The plan — not Medicare — then pays your doctors and hospitals.
The law sets a floor. Every plan must cover the same services Part A and Part B cover, with one exception: hospice care. Hospice stays with Original Medicare.
Most plans go further than the floor. In our 2026 analysis of CMS plan data, 92% of plans include Part D drug coverage. Most also add benefits Original Medicare has never covered, like routine dental, vision, and hearing care. Plans can do this because they run their own budgets. They set the copays, the network, and the rules — within limits Medicare sets each year.
All plan figures on this page come from The Pocket Protector’s analysis of 2026 CMS plan data: the 4,456 Medicare Advantage plans sold to individuals for 2026, including Special Needs Plans, in Washington, D.C. and every state except California and New York. Plans in those two states, plans in the U.S. territories, and employer-only plans are not included.
Two money facts stand out. First, 52% of plans charge a $0 monthly premium. You pay nothing beyond your Part B premium. Second, every plan caps what you pay out of pocket for in-network medical care each year — the services Part A and Part B cover. The median cap is $6,700. The highest is $9,250. Drug costs have their own separate yearly cap. Original Medicare on its own has no cap for medical care at all.
That cap is real protection. But it is a ceiling for a bad year, not what a typical year costs.
Medicare Advantage vs. Original Medicare: the honest trade-offs
Most comparison pages stop at premiums and perks. That leaves out the three things people most wish they had known: prior approval, networks, and the one-way door back to Medigap. Here is the whole picture — the good rows and the hard ones.
Medicare Advantage compared with Original Medicare, including advantages and disadvantages of each
Medicare Advantage (Part C) | Original Medicare (+ Medigap) | |
|---|---|---|
Monthly premium | Often $0 — 52% of plans. You still pay your Part B premium. | You pay the Part B premium. A Medigap policy and a Part D drug plan each add a premium of their own. |
Yearly cap on your costs | Yes, for covered medical care — the services Part A and Part B cover. Every plan caps your in-network costs for that care. The median cap is $6,700; the highest is $9,250. Once you hit it, the plan pays the full cost of that care for the rest of the year. Drug costs have their own separate yearly cap. | No cap on its own. For most Part B care you pay 20% of the approved cost, after the yearly Part B deductible, with no upper limit. That is the gap Medigap fills. |
Extra benefits | Most plans add extras Original Medicare lacks. 99% include vision benefits and 96% include hearing-aid benefits. About 8 in 10 include a dental benefit with a yearly dollar cap (median $2,000). | None. Original Medicare does not cover routine dental, vision, or hearing aids. |
Drug coverage | Usually built in — 92% of plans include Part D drug coverage. | Not included. You add a separate Part D drug plan, with its own premium. |
Which doctors you can see | A network. 62% of plans are HMO-type plans. Most pay for out-of-network care only in an emergency, for urgent care while you are away from home, or for out-of-area dialysis. PPO plans (37%) cover care outside the network, but you pay more. Networks can change every year. | Any doctor or hospital in the U.S. that accepts Medicare — and most do. No networks. |
Referrals to specialists | About 1 in 4 plans make you get a referral from your primary doctor before you see a specialist. | No referrals. You can go straight to any specialist who accepts Medicare. |
Prior approval for care | Nearly all: 99% of plans require prior authorization — the plan’s OK before it pays — for at least one service. The median plan requires it for 24 kinds of care. Hospital stays, nursing care, and scans are common examples. You can appeal a denial, and most appeals win. But that takes time when you are sick. | Rarely needed. For most care, if your doctor orders it and Medicare covers it, no one has to approve it first. |
Switching back later (the Medigap catch) | The catch the brochures skip. You can always return to Original Medicare in an enrollment window. But buying a Medigap policy afterward is not guaranteed. Outside a few protected windows, Medigap companies in most states can ask health questions. They can charge you more or turn you down. If your health has changed, you may be stuck. | No trap in this direction. Once you have a Medigap policy, it renews for life as long as you pay the premium. The company cannot drop you because you got sick. |
Plan statistics are The Pocket Protector’s analysis of CMS plan data for the 4,456 Medicare Advantage plans in our 2026 analysis. Every plan is different — always confirm details in a plan’s own documents.
The three catches, explained
1. Prior authorization: approval before care
In Original Medicare, most covered care just happens. Your doctor orders it, and Medicare pays its share.
Medicare Advantage plans work more like job-based insurance. In our 2026 analysis, 99% of plans require prior authorization for at least one service. That means the plan must say yes before it will pay. The median plan applies this to 24 kinds of care. It shows up most at the expensive moments: hospital stays, skilled nursing care, and imaging tests.
If the plan says no, you have the right to appeal, and most appeals win. In 2024, plans reversed about 8 in 10 of the denials that people appealed. But most people never file one. Only about 1 in 9 denials gets appealed at all — because an appeal is time and paperwork at exactly the moment you are sick.
2. Networks: your doctor is covered only while in one
Nearly every Medicare Advantage plan uses a network of doctors. In our 2026 analysis, 62% of plans are HMO-type plans. Most pay nothing for care outside the network — except in an emergency, for urgent care while you are away from home, or for out-of-area dialysis. PPO plans (37%) do cover out-of-network care, but you pay more for it.
Check two things before you enroll. Are your doctors and your hospital in the network today? And could you live with losing them? Networks and benefits can change every January, and a doctor can leave in the middle of the year.
Original Medicare has no network. Any doctor in the U.S. who accepts Medicare can treat you — and most do.
3. The Medigap catch: switching back is not guaranteed
This catch matters most in the long run, and plan marketing never mentions it.
Medigap — also called Medicare Supplement Insurance — helps pay the share of the bill that Original Medicare leaves to you. It cannot be used with a Medicare Advantage plan. And your right to buy Medigap without health questions is mostly a one-time offer. It lasts six months, starting the first month you are both 65 or older and signed up for Part B.
So what if you try Medicare Advantage and later want out? Federal law gives some people a 12-month trial right. You get it in two cases:
- You joined a Medicare Advantage plan when you first became eligible for Medicare at 65, and you leave within 12 months.
- You dropped a Medigap policy to join a Medicare Advantage plan for the first time, and you leave within 12 months.
In either case, you can buy a Medigap policy with no health questions. If neither case fits you, there is no federal trial right.
After that window, Medigap companies in most states can use medical underwriting. They review your health, and they can charge you more or turn you down. A cancer diagnosis, heart disease, or even some medications can put Medigap out of reach.
Some states add stronger rights. Certain events, like your plan leaving your area, can restore them. Before you count on switching back, read our plain-language guide to Medigap guaranteed-issue rights, state by state.
When you can join, switch, or leave
- When you first get Medicare: around your 65th birthday, or after 24 months of disability benefits. You pick Original Medicare or a Medicare Advantage plan.
- Annual enrollment (October 15 to December 7): each fall, anyone with Medicare can join, switch, or drop a plan for the coming year. Coverage starts January 1.
- Medicare Advantage open enrollment (January 1 to March 31): already in a Medicare Advantage plan? You get one switch — to another plan, or back to Original Medicare.
- Special windows: some life events, like moving out of your plan’s area, open extra windows. The 12-month trial right above is one of these protections.
Thinking about a Medicare Advantage plan? Compare the actual plans where you live. Premiums, networks, drug coverage, and caps vary a lot by county.
Compare Medicare Advantage plans in your area →
Sources
Every claim on this page was verified against these sources on August 3, 2026. Coverage rules and plan data change; this page is re-verified whenever they do.
- Medicare.gov — Compare Original Medicare & Medicare Advantage (what Part C plans must cover, including the hospice exception; networks, referrals, prior authorization, out-of-pocket limits, and Medigap compatibility)
- Medicare.gov — Joining a health or drug plan (enrollment periods and when coverage starts)
- Medicare.gov — When can I buy Medigap? (the six-month Medigap window, medical underwriting outside protected windows, and the two 12-month trial rights)
- Medicare.gov — What Medigap covers (Medigap helps pay your share of Original Medicare costs; it cannot be used with a Medicare Advantage plan)
- Medicare.gov — Hospice care (hospice is covered by Original Medicare Part A even if you are enrolled in a Medicare Advantage plan)
- Medicare.gov — Appeals in a Medicare health plan (your appeal rights when a Medicare Advantage plan denies care)
- KFF — analysis of CMS Medicare Advantage prior-authorization data for 2024 (the share of denials that were appealed, and the share of appealed denials that plans reversed)
- The Pocket Protector — analysis of CMS plan data (2026 Plan Benefit Package filings and the CMS Medicare Advantage landscape file), all 4,456 Medicare Advantage plans in our 2026 analysis — see the note under “How Medicare Part C works” for exactly what that covers (the plan statistics on this page: plan-type mix, $0-premium share, drug-coverage share, out-of-pocket caps, prior-authorization and referral prevalence, and extra-benefit prevalence)
Content on this page is educational, not medical or enrollment advice. Medicare Advantage benefits, networks, and costs are set by each plan and can change each year — always confirm details in the plan’s own documents before enrolling.