Quick answer: Medicare Advantage replaces Original Medicare with a single private plan that has a network and a yearly out-of-pocket limit. Medigap, also called Medicare Supplement Insurance, works alongside Original Medicare to help pay costs such as the 20% coinsurance, and it lets you use any doctor or hospital that takes Medicare. You cannot have both at the same time.
The choice comes down to how you want to trade premiums, flexibility and predictability. Here is how the two compare, who tends to choose each, and what happens if you change your mind later.
Medicare Advantage vs Medigap Side by Side
| Feature | Original Medicare with Medigap | Medicare Advantage |
|---|---|---|
| Doctors and hospitals | Any doctor or hospital in the U.S. that accepts Medicare | Generally the plan’s network and service area; some plans cover out-of-network care for more money |
| How you pay | Part B premium, your Medigap premium and a separate Part D premium | Part B premium plus any plan premium; some plans have a $0 premium; copays and coinsurance vary by plan |
| Yearly out-of-pocket limit | No yearly limit under Original Medicare alone; Medigap helps pay costs that would otherwise add up | Every plan has a limit; once you reach it you pay nothing for covered services for the rest of the year |
| Prescription drugs | Not included in Medigap; you join a separate Part D plan | Most plans include Part D drug coverage |
| Dental, vision and hearing | Original Medicare does not generally cover routine eye exams or most dental care | Plans may add some dental, vision and hearing benefits |
| Referrals and approvals | Usually no referral or prior authorization needed | You may need referrals to see specialists and prior authorization for some services |
| Travel outside the U.S. | Generally not covered; some Medigap plans cover emergency care abroad | Generally not covered; some plans offer emergency travel coverage |
These points come from Medicare.gov’s comparison of Original Medicare and Medicare Advantage.
How Medigap Works
Medigap policies are standardized and identified by letters. Within a given letter, the benefits are the same no matter which insurer sells the policy, so you are mainly comparing price and service. Plans C and F are generally not available to people who became eligible for Medicare on or after January 1, 2020. A Medigap policy only works with Original Medicare, and it does not include prescription drug coverage.
Timing matters. Your Medigap Open Enrollment Period lasts six months and begins the first month you are 65 or older and enrolled in Part B. That is the best time to buy. After it ends there is no federal guarantee that an insurer will sell you a policy, your health history can raise the price, and state rules differ. Learn more in our Medicare Supplement guide and the Turning 65 enrollment timeline.
How Medicare Advantage Works
With Medicare Advantage you still have Medicare and still pay the Part B premium, but a private plan delivers your benefits. The plan must cover everything Original Medicare covers, and it may add extras. You generally use the plan’s network, and every plan has a yearly limit on what you pay out of pocket for covered services.
For 2027, CMS projects the average monthly Medicare Advantage premium will fall from $14.37 to $12.00, and roughly 8 in 10 members can keep their current plan at the same or a lower premium (CMS announcement). Those are national averages, so compare the plans available in your county on our Medicare Advantage page.
Which One Tends to Fit Which Situation
Medigap tends to fit people who:
- Want to see any doctor or hospital that accepts Medicare, anywhere in the country.
- Prefer predictable out-of-pocket costs and are willing to pay a higher monthly premium for them.
- Travel within the U.S. or split time between states.
- Are inside their Medigap Open Enrollment Period, or expect to qualify with their health history.
Medicare Advantage tends to fit people who:
- Want a lower monthly premium and drug coverage bundled into one plan.
- Are comfortable using a network and getting referrals or approvals when required.
- Value extras such as dental, vision or hearing benefits.
- Like having a yearly cap on covered out-of-pocket costs.
Neither choice is better in every case. The right answer depends on your doctors, your prescriptions, your budget and how much cost variability you can tolerate.
Switching: What Happens If You Change Your Mind
The two directions are not equal. Moving from Original Medicare to Medicare Advantage is simple during Open Enrollment, which runs October 15 through December 7. Moving back to Original Medicare is also possible, but buying a Medigap policy afterward is not guaranteed. Unless a guaranteed issue right applies, such as your Medicare Advantage plan leaving Medicare or you moving out of its service area, insurers in most states can review your health history and charge more or decline.
Federal law also makes it illegal to sell you a Medigap policy while you are enrolled in a Medicare Advantage plan. If you are already in Medicare Advantage, you have an extra window from January 1 to March 31 to switch plans or return to Original Medicare. Our Medicare Annual Enrollment Period 2027 guide explains the dates and what you can change.
Questions to Ask Before You Choose
- Are my doctors and hospitals in the plan’s network, and will they stay in it for 2027?
- What is the plan’s maximum out-of-pocket amount, and what do the services I use most cost?
- Are my prescriptions covered, and at what tier and price?
- How often do I travel, and will I need care outside my plan’s area?
- If I choose Medicare Advantage now, how hard would it be to get Medigap later?
Get Help Comparing Your Options
All Solution Plus can compare Medigap and Medicare Advantage options available where you live, at no cost to you, and explain the trade-offs for your doctors and prescriptions.
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Frequently Asked Questions
Can I have Medigap and Medicare Advantage at the same time?
No. Federal law makes it illegal for someone to sell you a Medigap policy if you have a Medicare Advantage plan. Medigap only works with Original Medicare.
Is Medigap the same as Medicare Supplement Insurance?
Yes. Medigap is the common name for Medicare Supplement Insurance, a private policy that helps pay costs Original Medicare does not, such as the 20% coinsurance.
Which is cheaper, Medigap or Medicare Advantage?
Medicare Advantage often has a lower or $0 plan premium, but you may pay copays and coinsurance when you use care, up to the plan limit. Medigap usually has a higher premium and more predictable costs when you need care. Compare total yearly cost for your own situation.
Can I switch from Medicare Advantage back to Medigap later?
You can return to Original Medicare, but buying Medigap is not guaranteed. Unless a guaranteed issue right applies, insurers in most states can use your health history to set the price or decline, and state rules vary.
Does Medigap cover prescription drugs?
No. Medigap policies do not include drug coverage. If you have Original Medicare with Medigap, you join a separate Medicare Part D plan, while most Medicare Advantage plans include drug coverage.
This article is general educational information, not personalized advice. Plan availability, costs and benefits vary by location. All Solution Plus is not connected with or endorsed by the U.S. government or the federal Medicare program. See our Medicare disclaimer.
