Medicare Advantage vs. Medigap: Which Plan Type Fits Your Situation

The core difference: how each plan works

Medicare Advantage (also called Part C) is an all-in-one plan run by a private insurance company. It includes Part A (hospital), Part B (doctor visits), and usually Part D (prescription drugs) all bundled together. You pay a monthly premium, and the plan sets the rules: which doctors you can see, which hospitals you can use, and how much you pay when you need care.

Medigap (also called Supplemental Insurance) is different. It's a policy sold by a private insurance company that works alongside Original Medicare — the government program itself. You keep your Medicare coverage and add Medigap on top to cover costs that Medicare doesn't pay, like copayments and coinsurance. Medigap does not include prescription drug coverage; you buy that separately through Part D if you want it.

The practical difference: with Advantage, the insurance company controls your network and your out-of-pocket costs. With Medigap, you use any doctor or hospital that accepts Medicare, and the insurance company reimburses your share of the bill.

Key Takeaways

• Medicare Advantage limits you to in-network doctors and hospitals, while Medigap lets you see any provider who accepts Medicare.
• Medicare Advantage usually costs less per month but can have higher copayments and deductibles when you use care; Medigap has higher premiums but more predictable costs.
• Medicare Advantage includes prescription drug coverage in most plans; Medigap requires you to buy Part D separately.
• You can switch between Advantage and Medigap during the annual enrollment period (October 15 to December 7) or if you may have access to for a special circumstance.
• Medigap plans are standardized by the government, so Plan G from one company covers the same things as Plan G from another; Medicare Advantage plans vary by company and region.

Network restrictions and doctor choice

Medicare Advantage plans have a network — a list of doctors, hospitals, and specialists you're supposed to use. If you see someone outside the network, you pay more, sometimes much more. Some Advantage plans are HMOs, which means you must use in-network providers except in emergencies. Others are PPOs, which let you see out-of-network doctors but charge you a higher copayment.

This matters most if you have a doctor you want to keep seeing. Before you choose an Advantage plan, check whether your current doctors are in the network. Networks change year to year, and a doctor you used last year might not be in the plan this year.

Medigap has no network. You can see any doctor or specialist in the United States who accepts Medicare. This is the main reason people choose Medigap — freedom to keep their doctors and to see specialists without needing a referral.

Monthly costs and out-of-pocket spending

Medicare Advantage premiums are often lower than Medigap premiums — sometimes $0 per month. But the lower premium usually means higher costs when you actually use care. You'll pay copayments for doctor visits, coinsurance for hospital stays, and deductibles before coverage kicks in. These costs add up if you see doctors frequently or have a hospital stay.

Medigap premiums are higher — typically $100 to $300 per month depending on the plan and your age — but once you've paid the premium, your out-of-pocket costs are much lower. Some Medigap plans cover copayments and coinsurance almost entirely, so you pay very little when you see a doctor.

The trade-off is predictability. With Medigap, you know roughly what you'll pay each month. With Advantage, your costs depend on how much care you use. If you're healthy and see doctors rarely, Advantage is usually cheaper. If you have chronic conditions or see specialists regularly, Medigap often costs less overall.

Prescription drug coverage

Most Medicare Advantage plans include Part D (prescription drug coverage) as part of the package. The plan decides which drugs are covered and what you pay. If your medications aren't on the plan's formulary (the list of covered drugs), you either pay out of pocket or switch to a different drug.

Medigap does not include prescription drug coverage. You must buy Part D separately through a standalone plan. This gives you more choice — you can pick a Part D plan based on your specific medications rather than being locked into the drugs your Advantage plan covers.

If you have Medigap and don't buy Part D when you first become may be able to access, you may pay a penalty later if you do sign up. The penalty is permanent and based on how long you went without coverage.

Switching plans and lock-in periods

You can change your mind, but there are windows when you can do it. The main enrollment period runs from October 15 to December 7 each year. During this time, you can switch from Advantage to Medigap, from Medigap to Advantage, or from one Advantage plan to another.

If you switch from Advantage to Medigap, insurance companies can ask health questions or charge you more based on your health history — unless you switch during the first 12 months after you turn 65 and first enroll in Medicare Part B. This is called the Medigap Open Enrollment Period, and it's the easiest time to buy Medigap without health screening.

Special circumstances can open enrollment windows outside the annual period: if you move out of your plan's service area, if your plan leaves the market, or if you may have access to for Medicaid. If you think you have a special circumstance, contact Medicare at 1-800-MEDICARE to ask.

Standardized plans and how to compare

Medigap plans are standardized by federal law. There are ten different plan types (A, B, D, G, K, L, M, N, and two others), and each one covers the same benefits no matter which insurance company sells it. Plan G from Humana covers the same things as Plan G from United Healthcare. This makes it easy to compare — you just look at the price.

Medicare Advantage plans are not standardized. Each insurance company designs its own plan with its own network, copayments, and deductibles. You have to compare them one by one, looking at which doctors are in-network, what the copayments are, and whether your medications are covered.

Medicare.gov has a plan comparison tool that shows you Advantage and Part D plans available in your area. You can enter your doctors and medications to see which plans cover them. This is the fastest way to narrow down your options.

Who each plan type works best for

Medicare Advantage makes sense if: You're generally healthy, you don't mind using a specific network of doctors, you want low monthly premiums, and you want prescription drug coverage included. It also works well if you live in an urban area where many doctors are in-network.

Medigap makes sense if: You have a doctor you want to keep seeing, you see specialists regularly, you want predictable costs, or you live in a rural area where few doctors are in-network for Advantage plans. It also works well if you want to avoid the hassle of prior authorizations and referrals.

Some people switch back and forth. You might start with Advantage while you're healthy, then switch to Medigap later if you develop a chronic condition and want more freedom to see specialists.

Frequently Asked Questions

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

No. You can have either Advantage or Medigap, but not both. If you try to enroll in both, Medicare will cancel one of them. You choose one or the other during enrollment.

What happens to my Medicare Advantage coverage if I move to a different state?

Your plan's network is usually limited to a specific region. If you move out of the service area, your plan ends. You'll have a special enrollment period to choose a new plan in your new location, and you can switch to Medigap without health screening during this time.

Do I still pay Medicare premiums if I have Medicare Advantage?

Yes. You pay the Part B premium (the standard amount deducted from Social Security or paid directly to Medicare) plus the Advantage plan's monthly premium, which varies by plan. Some Advantage plans have $0 premiums, meaning you only pay Part B.

Can I switch from Medigap to Medicare Advantage without health screening?

Yes, you can switch during the annual enrollment period (October 15 to December 7) without health questions. Outside that window, Advantage plans don't ask health questions — they must accept anyone may be able to access for Medicare. The health screening only applies if you're switching from Advantage to Medigap.

What if my doctor leaves their practice or stops accepting Medicare?

With Medigap, you can see any other Medicare-accepting doctor without penalty. With Advantage, if your doctor leaves the network, you can either find a new in-network doctor or request an exception from the plan. Some plans allow you to continue seeing an out-of-network doctor at in-network rates if you've been seeing them regularly.