The core difference between Medicare Advantage and Medigap

Medicare Advantage and Medigap are two different ways to cover costs that Original Medicare (Parts A and B) does not pay. They work in opposite directions, and you choose one or the other — not both.

Medicare Advantage is an alternative to Original Medicare itself. You enroll in a plan run by a private insurance company, and that plan becomes your Medicare. It must cover everything Original Medicare covers, but it does so through its own network of doctors and hospitals. Most Advantage plans include prescription drug coverage (Part D) built in, and many add dental, vision, or hearing benefits. In exchange, you usually pay less in monthly premiums than you would for Original Medicare plus Medigap.

Medigap is a supplement to Original Medicare. You keep your Original Medicare coverage and buy a separate policy from a private insurer to fill the gaps — the deductibles, copayments, and coinsurance that Original Medicare leaves you responsible for. Medigap does not include prescription drug coverage; you buy that separately if you need it.

Key Takeaways

  • Medicare Advantage replaces Original Medicare with a private plan that usually costs less monthly but limits you to in-network doctors and hospitals.
  • Medigap supplements Original Medicare, lets you see any doctor who accepts Medicare, and typically costs more in monthly premiums but less out-of-pocket when you use care.
  • Medicare Advantage plans often include dental, vision, and hearing coverage; Medigap does not and requires a separate Part D prescription drug plan.
  • Your choice depends on whether you value lower monthly costs and extra benefits (Advantage) or predictable out-of-pocket costs and doctor choice (Medigap).
  • You can switch between them during the Annual Enrollment Period (October 15 to December 7 each year) or if you may have access to for a Special Enrollment Period.

How costs work in each plan type

Medicare Advantage plans typically have lower or zero monthly premiums than Medigap, but that is only the first piece of the cost picture. Advantage plans use copayments, coinsurance, and deductibles — sometimes high ones — when you see a doctor, go to the hospital, or need specialist care. You also pay out-of-pocket until you reach an annual out-of-pocket maximum, which protects you from catastrophic costs but means you bear the risk of high medical expenses in any given year.

Medigap plans have higher monthly premiums (often $100 to $300 or more, depending on the plan letter and your age), but once you meet the deductible — usually $226 per year for most plans — your out-of-pocket costs are predictable and often zero. You pay your Original Medicare deductible and coinsurance, and Medigap covers the rest. This means your total healthcare costs are easier to budget, and you face less financial surprise if you need expensive care.

The trade-off is real: Advantage plans bet that you will not need much care or will stay in-network; Medigap plans bet that predictability and access matter more than saving on premiums. Which costs less over a year depends entirely on your health, how often you see doctors, and which specialists you need.

Network restrictions and doctor choice

Medicare Advantage plans are HMOs or PPOs — both use networks. An HMO requires you to choose a primary care doctor and get referrals to see specialists; you pay nothing or very little if you stay in-network, but out-of-network care is usually not covered except emergencies. A PPO lets you see any doctor in its network without a referral and offers some out-of-network coverage, but at a higher cost to you.

Medigap has no network. You can see any doctor in the United States who accepts Medicare — and the vast majority do. You do not need referrals, and you do not need permission from an insurance company to see a specialist. This freedom is one of Medigap's biggest advantages, especially if you have a doctor you want to keep or if you travel and want to see doctors in different states.

If your current doctors are in your local Advantage plan's network and you rarely travel, network restrictions may not matter to you. If you have a specialist you see regularly, live in a rural area with fewer in-network options, or travel frequently, Medigap's open access is usually worth the higher premium.

Prescription drug coverage and extra benefits

Most Medicare Advantage plans include Part D prescription drug coverage at no extra cost. Some plans also cover dental cleanings and exams, vision exams and glasses, hearing exams and hearing aids, and fitness benefits like gym memberships. These extras can add real value if you use them.

Medigap does not include any of these. You must buy a separate Part D plan for prescriptions, and you pay out-of-pocket for dental, vision, and hearing care — or you buy separate policies for those, which can be expensive. If you take multiple medications, need dental work, or wear glasses or hearing aids, the cost of Medigap plus these separate coverages can exceed what an Advantage plan costs.

However, Advantage plans' extra benefits vary widely by plan and by year. A plan that covers dental one year may change its coverage the next year. Read your plan's summary of benefits each year during open enrollment to see what is actually covered and what you would pay.

Switching plans and enrollment windows

You can switch between Medicare Advantage and Medigap once a year during the Annual Enrollment Period, which runs from October 15 to December 7. Changes take effect January 1. You can also switch if you may have access to for a Special Enrollment Period — for example, if you move out of your plan's service area, lose employer coverage, or move into or out of a nursing home.

If you are switching from Medigap to Medicare Advantage, you do not need to worry about medical underwriting; Advantage plans must accept you. If you are switching from Medicare Advantage to Medigap, the rules are stricter. You have a may provide right to buy Medigap without medical underwriting only during your first six months with Original Medicare or if you are dropping Advantage coverage within 12 months of first enrolling in it. Outside those windows, insurers can deny you or charge more based on your health history.

This asymmetry matters: switching to Advantage is always possible, but switching back to Medigap later may be harder or more expensive. If you are considering Medigap, it is usually better to enroll sooner rather than later.

Who typically chooses each plan type

Medicare Advantage works well if you are generally healthy, see doctors infrequently, are willing to use in-network providers, and value lower monthly premiums and extra benefits like dental or vision. It also suits people on a tight budget who cannot afford Medigap premiums. Advantage plans are common in urban and suburban areas where networks are robust.

Medigap works well if you have chronic conditions, see multiple specialists, want to keep your current doctors, travel frequently, or live in a rural area. It also suits people who value predictable costs and do not want to worry about deductibles or out-of-pocket maximums. Medigap is more common among people with higher incomes who can afford the premiums.

Neither choice is objectively "better" — it depends on your health, your doctors, your budget, and what matters most to you. The best plan is the one that covers your doctors and fits your finances.

Frequently Asked Questions

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

No. You choose one or the other. If you enroll in Medicare Advantage, you cannot also buy Medigap. If you have Medigap and enroll in Advantage, your Medigap policy ends. Medicare does not allow you to hold both because Advantage already includes coverage that Medigap would duplicate.

What happens to my Medicare Advantage plan if I move?

If you move outside your plan's service area, you lose that plan. You can switch to a different Advantage plan in your new area or switch to Original Medicare plus Medigap during your Special Enrollment Period. You have two months from the month you move to make this change.

Do I still pay Medicare Part B premiums if I choose Medicare Advantage?

Yes. You pay your Part B premium (currently around $165 per month for most people, though it varies by income) whether you choose Advantage or Medigap. Advantage plans may have an additional monthly premium on top of that, or they may have zero premium.

Which plan type is cheaper for someone with multiple chronic conditions?

Usually Medigap, because you will likely hit your Advantage plan's out-of-pocket maximum quickly, and then you still pay coinsurance. With Medigap, once you meet the deductible, most of your costs are covered. However, you must compare the actual plans available to you — costs vary by location and by year.

Can I switch from Medicare Advantage to Medigap without medical underwriting?

Yes, if you are within 12 months of first enrolling in Medicare Advantage. After that window closes, insurers can deny you or charge more based on your health. This is why switching back to Medigap later can be risky — plan ahead if you think you might want to switch.