Medicare Advantage vs. Medigap: which one fits you?
The short answer
Medicare Advantage is a private plan you get your Medicare through instead of Original Medicare, while Medigap is a policy you add to Original Medicare to help pay the costs it leaves behind. You can’t have both at once. Medicare Advantage often means a network of doctors, costs as you use care and a yearly limit on what you pay. Original Medicare with Medigap means any doctor in the U.S. who takes Medicare, with the policy paying much of your share, for a separate monthly premium. And the easiest time to buy Medigap comes only once.
This is the decision almost every one of my Medicare clients starts with, and the names don’t help. “Advantage” sounds like an upgrade, and “Supplement” sounds like an add-on to the same thing. Neither is quite right.
Here is how each one works, side by side, the timing rule that surprises people later, and the questions I would ask before choosing. Everything here comes from Medicare’s own pages.
Two different ways to get Medicare
Once you have Part A and Part B, Medicare gives you two main ways to get your coverage:
- Original Medicare. You pay for services as you get them. Medicare pays its part and you pay your share, usually 20% of the Medicare-approved amount for Part B services after the yearly Part B deductible ($283 in 2026). You can add a separate drug plan (Part D) and supplemental coverage, such as a Medigap policy, to help pay your share.
- Medicare Advantage (Part C). You join a plan from a private company with a Medicare contract, and it takes the place of Original Medicare for your health coverage. Most plans include drug coverage too.
Medigap only works with Original Medicare. You can’t buy Medigap while you are in a Medicare Advantage plan, unless you are switching back to Original Medicare, and Medigap can’t pay a Medicare Advantage plan’s copays, deductibles or premiums. So the real choice is Original Medicare, usually with Medigap and a drug plan, or a Medicare Advantage plan.
Side by side
| Original Medicare + Medigap | Medicare Advantage | |
|---|---|---|
| Doctors and hospitals | Any doctor or hospital that takes Medicare, anywhere in the U.S. | Usually the plan’s network and service area for non-emergency care; some plans cover out-of-network care at a higher cost |
| Specialists | In most cases, no referral needed | You may need a referral |
| Approval before care | In most cases, not needed | You may need prior authorization for certain services |
| Yearly limit on what you pay | None in Original Medicare itself; Medigap pays much of your share | Yes, every plan has a yearly limit for covered services |
| Drug coverage | A separate Part D plan (Medigap sold after 2005 doesn’t include drugs) | Included in most plans |
| Dental, vision, hearing | Medigap generally doesn’t cover them | Plans may offer some extra benefits like these; they vary by plan |
| Travel outside the U.S. | Some Medigap plans cover emergency care abroad, up to plan limits | Generally not covered; some plans offer it as an extra |
| Monthly cost | Part B premium, plus a Medigap premium and a drug plan premium | Part B premium, plus the plan’s premium if it has one |
Medigap, in plain words
Medigap, or Medicare Supplement Insurance, is a policy from a private insurance company that helps pay your share of costs in Original Medicare, like deductibles, coinsurance and copays.
- The plans are standardized. Policies with the same letter offer the same basic benefits no matter which company sells them; price is the only difference. Most states offer 10 lettered plans: A–D, F, G and K–N.
- Plan G and Plan N are two that people often compare. Plan G covers every benefit in Medicare’s chart except the Part B deductible. Plan N also leaves the Part B deductible to you, doesn’t cover Part B excess charges, and has copays of up to $20 for some office visits and up to $50 for emergency room visits when you aren’t admitted.
- Plans C and F aren’t sold to everyone. Whether you can buy them depends on when you first became eligible for Medicare.
- It covers one person. If you and your spouse both want Medigap, you each buy your own policy.
- It renews. Once you have a standardized policy, it renews every year as long as you pay the premium, even if your health changes.
- No drugs, no dental. Policies sold after 2005 don’t include drug coverage, so you add a Part D plan. Medigap generally doesn’t cover dental, vision, hearing aids, glasses or long-term care.
Medicare Advantage, in plain words
A Medicare Advantage plan is run by a private company with a Medicare contract. It must cover all the medically necessary services Original Medicare covers, and most plans include drug coverage.
- Networks. In many cases you use the doctors and hospitals in the plan’s network. Before you pick a plan, check that your doctors are in it.
- Costs as you go. What you pay when you get care varies by plan and by service.
- A yearly cap. Every plan has a yearly limit on what you pay for covered Medicare services. Once you reach it, you pay nothing more for covered services for the rest of the year. Some plans set separate limits for care in and out of the network.
- Extras. Plans may offer extra benefits Original Medicare doesn’t cover, like some vision, hearing and dental services. I wrote a separate guide on what Medicare covers for dental, vision and hearing.
- Approvals. You may need a referral to see a specialist, or the plan’s approval before it covers certain services.
The timing rule that matters most
Your Medigap Open Enrollment Period lasts six months. It starts the first month you have Part B and are 65 or older, and it happens only once. During those six months you can buy any Medigap policy, and the company can’t turn you down because of your health. After it, you may not be able to buy a Medigap policy, or it may cost more.
That is why this choice deserves the most care at 65. Two federal protections soften it:
- If you join Medicare Advantage when you first get Medicare at 65 and switch back to Original Medicare within the first year, you can buy certain Medigap policies.
- If you drop a Medigap policy to try Medicare Advantage for the first time, you have a single 12-month trial right to get your Medigap policy back, if the same company still sells it.
Changing later
Medicare’s Open Enrollment, from October 15 to December 7 each year, is when you can switch from Original Medicare to a Medicare Advantage plan or back, or change plans. Changes start January 1. Going back to Original Medicare is always possible then; getting a Medigap policy to go with it may not be, outside the protections above.
How I would think about it
- If you want to keep seeing a particular doctor or hospital, or you spend part of the year in another state, Original Medicare with Medigap lets you use any provider in the U.S. that takes Medicare.
- If you would rather have one plan with drug coverage and some extras built in, and your doctors are in its network, Medicare Advantage is built for that.
- If you have health conditions now, think hard about the Medigap window at 65. During it, a company can’t turn you down for your health; later, it may.
- Either way, check your prescriptions against the plan’s list of covered drugs before you choose.
Where I come in
I am an independent agent, so we start from your doctors, your prescriptions and how you like to get care, then look at what the plans I offer in your area include, Medigap and Medicare Advantage side by side. There is no cost for my help, and I work by phone or video, in English or Spanish. More on how I help with Medicare.
Questions people ask
What is the main difference between Medicare Advantage and Medigap?
Medicare Advantage is a private plan you get your Medicare coverage through instead of Original Medicare. Medigap is a policy you add to Original Medicare to help pay your share of the costs, like deductibles and coinsurance.
Can I have Medicare Advantage and Medigap at the same time?
No. You can’t buy Medigap while you are in a Medicare Advantage plan unless you are switching back to Original Medicare, and Medigap can’t pay a Medicare Advantage plan’s copays, deductibles or premiums.
When is the Medigap Open Enrollment Period?
It lasts six months, starting the first month you have Part B and are 65 or older, and it happens only once. During it, an insurance company can’t turn you down for a Medigap policy because of your health.
Can I switch from Medicare Advantage back to Original Medicare?
Yes, during Medicare’s Open Enrollment from October 15 to December 7, with changes starting January 1. Buying a Medigap policy at that point is not guaranteed unless a protection like the 12-month trial right applies.
What is the difference between Medigap Plan G and Plan N?
Both leave the Part B deductible to you. Plan N also doesn’t cover Part B excess charges and has copays of up to $20 for some office visits and up to $50 for emergency room visits when you aren’t admitted. Plan G covers excess charges and has no such copays.
Is there an out-of-pocket maximum in Medicare Advantage?
Yes. Every Medicare Advantage plan has a yearly limit on what you pay for covered Medicare services. Once you reach it, you pay nothing more for covered services for the rest of the year.
Sources
- Medicare.gov — Your coverage options
- Medicare.gov — Compare Original Medicare & Medicare Advantage
- Medicare.gov — Get Medigap basics (Medigap Open Enrollment)
- Medicare.gov — Learn what Medigap covers
- Medicare.gov — Compare Medigap plan benefits
- Medicare.gov — Learn how Medigap works (Medicare Advantage, trial rights)
- Medicare.gov — When can I buy a Medigap policy? (state rights)
- Medicare.gov — Open Enrollment (October 15 – December 7)
- CMS — 2026 Medicare Parts A & B premiums and deductibles
Figures are the ones the source published for the year shown. Programs update their limits every year — if you are reading this later, check the source or call me.
More guides
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