Part C is Medicare Advantage — a private insurance alternative to Original Medicare
Part C, officially called Medicare Advantage, is a way to get your Medicare coverage through a private insurance company instead of directly from the federal government. If you have Part A (hospital insurance) and Part B (medical insurance), you can choose to switch to a Medicare Advantage plan instead. The private insurer then becomes responsible for covering everything Original Medicare covers — hospital stays, doctor visits, tests — plus usually some extras like dental or vision that Original Medicare does not include.
The trade-off is that Medicare Advantage plans typically have networks. You usually must see doctors and hospitals within that network, or pay more out of pocket. You also cannot use a Medigap supplemental policy alongside Part C — the two are mutually exclusive. Most Medicare Advantage plans charge a monthly premium in addition to your Part B premium, though some have zero premium.
About 4 in 10 people with Medicare choose Part C instead of staying in Original Medicare. The appeal is usually the lower out-of-pocket costs for routine care, the included extras, and the predictable annual spending cap. The drawback is less flexibility in choosing providers and less coverage if you travel or need care outside the plan's network.
Key Takeaways
- Medicare Advantage is run by private insurance companies but must cover everything Original Medicare covers, plus usually dental, vision, or hearing benefits.
- You must use doctors and hospitals in the plan's network for full coverage, unless it is an out-of-network emergency.
- You cannot have both Medicare Advantage and a Medigap policy at the same time.
- Most plans have a yearly out-of-pocket spending limit, after which the plan pays 100 percent of covered services for the rest of the year.
- You can switch back to Original Medicare during the annual enrollment period (October 15 to December 7) or if you move out of the plan's service area.
How Medicare Advantage plans cover your costs
Every Medicare Advantage plan must cover hospital care, doctor visits, and medical equipment — the same things Original Medicare covers. But the way you pay is different. Instead of paying a deductible and then coinsurance for each service, most Medicare Advantage plans use copays: a fixed dollar amount per visit or service. A copay might be $15 for a doctor visit, $250 for an emergency room visit, or $0 for preventive care.
Plans also set an annual out-of-pocket maximum. Once you have paid that amount in copays and coinsurance in a calendar year, the plan covers 100 percent of your remaining covered services. This maximum varies by plan but is capped by Medicare at around $7,000 to $8,000 for in-network care, depending on the year. Original Medicare has no such cap, which is why some people prefer it.
Most Medicare Advantage plans include extras that Original Medicare does not: dental (cleanings, fillings, sometimes dentures), vision (eye exams, glasses or contacts), hearing (exams and hearing aids), and fitness benefits (gym memberships or classes). Some plans also cover transportation to medical appointments or meal delivery. These extras vary widely by plan and by region.
Network restrictions and what they mean for your care
A Medicare Advantage plan's network is the list of doctors, hospitals, and other providers that have agreed to work with that plan. If you see a doctor in the network, you pay the copay or coinsurance the plan sets. If you see a doctor outside the network, you typically pay much more — sometimes the full bill — unless it is an emergency.
Some plans are HMOs (Health Maintenance Organizations), which require you to pick a primary care doctor. That doctor coordinates your care and must refer you to specialists. Other plans are PPOs (Preferred Provider Organizations), which let you see specialists without a referral and usually have larger networks. A few plans are PFFS (Private Fee-for-Service), which work more like Original Medicare but still require you to check whether a provider accepts the plan.
Before you join a Medicare Advantage plan, check whether your current doctors are in the network. If your doctor is not listed, contact the plan directly — networks change, and the online directory is not always current. If you move, your plan may no longer serve your new address, and you will have the right to switch to Original Medicare or a different plan.
Costs you pay with Medicare Advantage
Most Medicare Advantage plans charge a monthly premium on top of your Part B premium. This premium varies by plan and by region — it might be $0, or it might be $200 or more per month. Some plans with zero premium make up the difference through higher copays or a smaller network.
You also pay copays and coinsurance when you use care. A typical plan might charge $0 for preventive visits, $20 to $50 for a doctor visit, $250 for an emergency room visit, and $100 to $300 per day for a hospital stay (up to a limit). Prescription drugs are usually included in Medicare Advantage plans, with copays that vary by drug tier.
You continue to pay your Part B premium to Medicare, even if you are in a Medicare Advantage plan. If you have not yet started Part B, you must do so before you can join Part C. You do not pay a separate Part A premium if you have already paid into it through payroll taxes.
When you can join or switch Medicare Advantage plans
You can join a Medicare Advantage plan during your initial enrollment period, which is the seven months surrounding your 65th birthday (three months before, the month of, and three months after). If you miss this window, you can still join during the annual enrollment period: October 15 to December 7 each year. Coverage begins January 1.
If you are already in Original Medicare, you can switch to Medicare Advantage during the annual enrollment period. If you are already in a Medicare Advantage plan, you can switch to a different Medicare Advantage plan or back to Original Medicare during the same window. You can also switch if you move out of your current plan's service area, or if you lose coverage through an employer.
There is also a Medicare Advantage open enrollment period from January 1 to March 31 each year. During this time, if you are already in a Medicare Advantage plan, you can switch to a different plan or to Original Medicare. You cannot use this window to join Medicare Advantage for the first time.
Medicare Advantage versus Original Medicare: the main differences
| Feature | Medicare Advantage (Part C) | Original Medicare (Parts A & B) |
|---|---|---|
| Who provides coverage | Private insurance company | Federal government |
| Provider network | Must use in-network providers (except emergencies) | Can see any provider who accepts Medicare |
| Supplemental insurance (Medigap) | Not allowed | Can purchase separately |
| Prescription drug coverage | Usually included | Must purchase Part D separately |
| Dental, vision, hearing | Usually included | Not covered |
| Annual out-of-pocket cap | Yes, typically $7,000–$8,000 | No limit |
| Travel coverage | Limited outside service area | Covered anywhere in the U.S. |
Things to watch out for when choosing a Medicare Advantage plan
Check the plan's service area before you join. Medicare Advantage plans are regional — they may cover your city but not the next county over. If you travel frequently or split time between two homes, Original Medicare may be more convenient because it works anywhere in the United States.
Look at the formulary, which is the list of prescription drugs the plan covers. If you take medications regularly, make sure your drugs are on the formulary and check what tier they are on — higher tiers mean higher copays. Formularies change each year, so even if your drug was covered last year, it may not be this year.
Ask about prior authorization requirements. Some plans require your doctor to get permission from the insurance company before you can have certain tests, procedures, or specialist visits. This can delay care and add frustration. Original Medicare does not require prior authorization for most services.
Review the plan's quality ratings on Medicare.gov. Medicare publishes star ratings for each plan based on member satisfaction, quality of care, and customer service. A plan with low ratings may have long wait times or poor customer support. These ratings change annually.
Frequently Asked Questions
Can I switch from Medicare Advantage back to Original Medicare?
Yes, during the annual enrollment period (October 15 to December 7) or the Medicare Advantage open enrollment period (January 1 to March 31). If you switch back to Original Medicare, you may want to purchase a Medigap policy to cover costs that Original Medicare does not pay. You have a limited time window to buy Medigap without medical underwriting.
Do I need Part D prescription drug coverage if I have Medicare Advantage?
No. Most Medicare Advantage plans include prescription drug coverage. However, if your plan does not include it, you must purchase Part D separately or pay a penalty if you go without coverage. Check your plan's documents to confirm whether drugs are included.
What happens to my Medicare Advantage coverage if I move?
If you move outside your plan's service area, you can switch to Original Medicare or a different Medicare Advantage plan that serves your new location. You have 60 days from the date you move to make the change. Contact your plan to confirm whether your new address is still in the service area.
Can I use my Medicare Advantage plan when I travel outside the United States?
No. Medicare Advantage plans do not cover care outside the United States. If you travel internationally, you will need to purchase travel health insurance separately. Original Medicare also does not cover care outside the U.S., except in limited cases near the border.
What is the difference between a Medicare Advantage HMO and PPO?
An HMO requires you to choose a primary care doctor who coordinates your care and refers you to specialists. A PPO lets you see specialists without a referral and usually has a larger network. PPOs typically have higher premiums and copays but more flexibility. HMOs are usually cheaper but more restrictive.