The core difference: how each plan pays your bills

Medicare Advantage (Part C) is an all-in-one plan run by a private insurance company. It includes hospital, doctor, and prescription drug coverage in one policy. You pay a monthly premium, and the plan decides which doctors and hospitals you can use — usually through a network. You also pay a copay or coinsurance when you see a doctor.

Medigap (also called a supplement) is a separate insurance policy sold by a private company that works alongside Original Medicare (Parts A and B). Medigap pays some or all of the costs that Medicare does not cover — like copays, coinsurance, and deductibles. You keep your choice of any doctor or hospital that takes Medicare.

The practical difference: with Advantage, the insurance company controls your network and your out-of-pocket costs are capped. With Medigap, you have freedom to see any Medicare provider, but you pay more upfront and the supplement reimburses you later.

Key Takeaways

  • Medicare Advantage limits you to in-network doctors and hospitals, while Medigap lets you see any doctor that accepts Medicare.
  • Advantage plans include prescription drug coverage; Medigap does not, so you must buy Part D separately.
  • Advantage has a yearly out-of-pocket spending cap; Medigap does not, so your costs can be unpredictable.
  • Medigap premiums are usually higher but more stable; Advantage premiums are lower but you pay more at the doctor's office.
  • Switching between them is easiest during the annual open enrollment period (October 15 to December 7), though some moves are allowed outside that window.

Network restrictions and doctor choice

With Medicare Advantage, you must use doctors and hospitals in the plan's network, except in emergencies. If you see an out-of-network provider, you pay much more — sometimes the full bill. Some Advantage plans offer a small out-of-network benefit, but it is limited. If you have a doctor you want to keep seeing, you must check whether they are in the plan's network before you sign up.

Medigap has no network. You can see any doctor, specialist, or hospital in the United States that accepts Medicare. This matters most if you travel, if you have a long-term relationship with a specific doctor, or if you live in a rural area where few doctors accept Advantage plans. The tradeoff is that Medigap costs more in monthly premiums.

Out-of-pocket costs and spending caps

Medicare Advantage plans have a yearly out-of-pocket maximum — the most you will pay in copays and coinsurance combined. Once you hit that cap, the plan pays 100 percent of covered services for the rest of the year. In 2024, this cap ranges from about $6,700 to $10,000 depending on the plan, though these numbers change yearly. This cap protects you from catastrophic costs if you have a serious illness or need many doctor visits.

Medigap plans have no spending cap. You pay the monthly premium, and then the plan reimburses you for covered costs. Some Medigap plans cover copays and deductibles completely; others cover most but not all. Your total costs depend on how much medical care you use and which Medigap plan you choose. If you are healthy and use little care, Medigap can be cheaper. If you have chronic conditions or need frequent hospital stays, the Advantage cap may save you money.

Prescription drug coverage

All Medicare Advantage plans must include prescription drug coverage (Part D). The copays and deductibles for drugs count toward your yearly out-of-pocket maximum. This is convenient because everything is in one plan.

Medigap does not include drug coverage. You must buy a separate Part D plan from an insurance company. Your drug copays do not count toward any spending cap — you pay them on top of your Medigap premium and your Original Medicare costs. If you take many medications or expensive drugs, this can add up quickly. However, you can change your Part D plan every year during the open enrollment period, so you can shop for the best drug coverage annually.

Monthly premiums and total costs

Medicare Advantage premiums are usually lower than Medigap premiums — sometimes zero dollars per month. However, you pay more when you actually use care: copays for doctor visits, specialist visits, and hospital stays. The total cost depends on how much medical care you use.

Medigap premiums are typically higher — often $100 to $300 per month depending on your age and location — but you pay little or nothing at the doctor's office. Some Medigap plans have a deductible (usually $226 per year in 2024), but after that, the plan covers most costs. Your total yearly cost is more predictable because you know your premium upfront.

Neither type of plan is automatically cheaper. If you rarely see a doctor, Advantage saves money. If you see doctors frequently or have chronic conditions, Medigap may cost less overall. The only way to know is to add up the premiums and expected out-of-pocket costs for your situation.

When you can switch between plan types

The easiest time to switch is during the Annual Enrollment Period (October 15 to December 7). During this window, you can move from Advantage to Medigap, from Medigap to Advantage, or change to a different plan within either category. Changes take effect January 1.

Outside this window, your options are limited. If you have Original Medicare and want to buy Medigap, you have a may provide issue period of 63 days after your Part B coverage starts — the insurance company cannot deny you or charge more based on health. If you are switching from Advantage to Medigap outside the enrollment period, the insurance company can charge more or deny coverage based on your health history, unless you may have access to for a special circumstance (like moving out of your plan's service area).

If you are on Medigap and want to switch to Advantage, you can do so during the enrollment period, but you cannot switch back to Medigap later without facing higher premiums or denial, unless you meet specific conditions.

Which plan type works for different situations

Choose Medicare Advantage if: You are willing to use doctors in a specific network. You want lower monthly premiums. You want prescription drug coverage included. You do not travel much or are comfortable finding in-network care when you do. You are relatively healthy or want a predictable yearly spending cap.

Choose Medigap if: You have a doctor you want to keep seeing and they may not be in an Advantage network. You travel frequently or live part-time in multiple states. You want maximum flexibility in choosing providers. You are willing to pay higher premiums for lower costs at the doctor's office. You prefer predictable, stable costs. You do not want to shop for a separate drug plan every year.

Frequently Asked Questions

Can I switch from Advantage to Medigap if I am unhappy with my network?

During the Annual Enrollment Period (October 15 to December 7), yes. Outside that window, you can switch only if you have a may have access to life event — like moving out of your plan's service area, losing employer coverage, or becoming may be able to access for Medicaid. Otherwise, the Medigap insurance company can charge you more or deny coverage based on your health.

Do I need Part D if I have Medigap?

Yes. Medigap covers doctor and hospital costs, not prescriptions. You must buy a separate Part D plan. If you do not sign up for Part D when you first become may be able to access, you may pay a penalty when you do sign up later.

What happens if I see an out-of-network doctor with Medicare Advantage?

You pay much more — sometimes the full bill. Some Advantage plans cover emergency out-of-network care, but routine visits to out-of-network doctors are not covered. Always check the network before scheduling an appointment.

Is Medigap more expensive than Medicare Advantage?

The monthly premium usually is, but total costs depend on how much care you use. If you see doctors frequently, Medigap may cost less overall because you pay little at the office. If you rarely see a doctor, Advantage premiums are lower and you may never hit the out-of-pocket cap.

Can I have both Medicare Advantage and Medigap at the same time?

No. You can have either Advantage or Original Medicare with Medigap, but not both. If you try to enroll in both, Medicare will cancel one of them.