Medicare Advantage vs Medicare Supplement — which is right for you?
Both routes give you real coverage on top of Original Medicare, but they work very differently. Advantage plans often have low premiums and built-in extras but come with networks and prior authorization. Medigap costs more each month but behaves more like old-fashioned "go anywhere" coverage with predictable out-of-pocket costs. Here's how to tell which side of the line you fall on.
Key takeaways
- Medicare Advantage bundles Parts A, B, and usually D into one private plan, often with a $0 premium and dental/vision extras — but uses a regional network and prior auth
- Medigap (Medicare Supplement) pairs with Original Medicare and has no network — see any provider that accepts Medicare nationwide
- Your 6-month Medigap Open Enrollment Period is one-time and starts the month you turn 65 AND have Part B — outside it, carriers can underwrite
- You can always switch FROM Medigap TO Advantage, but going the other direction usually requires passing health underwriting
- Lowest total cost depends on health: heavy users often save with Medigap; healthy in-network folks often save with Advantage
On this page
How each one actually works
Both options require you to already be enrolled in Medicare Parts A and B. Where they diverge is in how claims get paid, who you can see, and what you owe out of pocket.
Medicare Advantage (Part C)
A private plan that replaces Original Medicare for the way you pay and access care. The plan contracts with Medicare to deliver your Part A and Part B benefits, usually bundles Part D, and often adds extras like dental, vision, hearing, or fitness.
- Typically an HMO or PPO network
- Copays per visit or service, plus a legally required annual out-of-pocket maximum
- Many plans have $0 premiums beyond your Part B premium
- Prior authorization is common for imaging, surgery, and therapy
Medicare Supplement (Medigap)
A private policy that pairs with Original Medicare. You still use Parts A and B; the Medigap plans pays some or most of the deductibles, coinsurance, and copays Medicare leaves behind.
- No network — any provider who accepts Medicare
- Higher monthly premium, lower and more predictable out-of-pocket costs
- Does not include drug coverage — you add a standalone Part D plan
- No prior authorization from the Medigap plan itself
Who you can see, and where
Medicare Advantage plans are usually built around a regional network. HMO plans generally require you to stay in network outside of emergencies. PPO plans let you go out of network but charge more. If your specialist, cancer center, or preferred hospital isn't contracted with the plan, that matters.
Medigap doesn't have a network. If a provider accepts Original Medicare — and most do — your Medigap policy follows the claim and pays its share. That's a meaningful difference for people who split time between states, snowbird in winter, or have a specialist in a different city.
Travel: Medigap generally travels well across all 50 states. Most Advantage plans limit non-emergency care to their service area. Some Medigap plans also offer limited foreign travel emergency benefits for the first 60 days of a trip.
Out-of-pocket costs in real terms
The right comparison isn't just premium — it's premium plus what you'll likely spend when you actually use care.
Medicare Advantage
You often pay a low or $0 plan premium (on top of the standard 2026 Part B premium of $185/month). In exchange, you pay copays and coinsurance when you use services — for example, a copay for each primary care visit, a higher copay for specialists, and daily copays for inpatient hospital stays.
Every Advantage plan is required to have a yearly maximum out-of-pocket cap on in-network Part A and B services. Once you hit it, the plan covers 100% for the rest of the calendar year. That cap varies by plan and can be several thousand dollars.
Medigap
Higher monthly premium, typically lower exposure when you use care. Depending on the letter plan (Plan G and Plan N are the most common for people newly eligible), you may owe very little beyond the Part B deductible for covered services.
For someone who uses a lot of care or wants predictability, that trade can be worth it. For someone in good health who rarely sees the doctor, the Advantage route may be cheaper overall — as long as the network works for them.
Want help running the numbers for you?
Tell us your doctors, your medications, and roughly how often you use care — we'll show you the actual total cost of Advantage and Medigap side-by-side in your ZIP. No-pressure, free, and you keep the comparison.
The 6-month Medigap window you only get once
Your Medigap Open Enrollment Period is a one-time, 6-month window that starts the first month you are both 65 or older and enrolled in Part B. During this window:
- Carriers cannot deny you a Medigap policy
- They cannot charge you more based on your health
- They cannot impose waiting periods for most pre-existing conditions
Outside this window, most states allow medical underwriting for Medigap. That means if you pick Medicare Advantage at 65 and decide a few years later you want Medigap, the carrier can ask health questions and may decline you or quote a higher premium.
The practical takeaway: if there's any chance you'd want Medigap, it's generally easiest and cheapest to start with it during this one-time window. Switching into Medigap later is often possible, but not guaranteed.
What if you change your mind?
From Medigap to Medicare Advantage
This direction is typically the easier one. You can generally move into a Medicare Advantage plan during the Annual Enrollment Period (October 15 – December 7) for a January 1 effective date. Advantage plans usually cannot medically underwrite you.
From Medicare Advantage to Medigap
You can leave Advantage during AEP or the MA Open Enrollment Period (January 1 – March 31) and go back to Original Medicare. Getting a Medigap policy at that point, though, usually involves health underwriting in most states. Plan ahead — don't assume.
Frequently asked
Which plan has lower total costs?
Do I still pay my Part B premium on Medicare Advantage?
Can I have both a Medigap plan and a Medicare Advantage plan?
What about dental, vision, and hearing?
Do my doctors take Medicare Advantage?
Not sure which side you're on?
Talk through your options with a licensed SilverEdge advisor. We'll look at your providers, your medications, and how you actually use care — then walk through the numbers on both paths.