Quick answer
Medicare Advantage is an all-in-one private plan that replaces Original Medicare, usually with a low or $0 premium, a yearly out-of-pocket limit, a provider network and prior approval rules. Medigap is a supplement you add to Original Medicare: it costs more each month, but you can see any doctor who takes Medicare and your bills are predictable. The biggest thing to know is timing. Your best chance to buy Medigap without health questions is your first six months with Part B.
Key takeaways
- 35.2 million people, or 55% of those eligible, are in Medicare Advantage in 2026.
- Medicare Advantage out-of-pocket costs are capped at up to $9,250 in network in 2026 and $9,850 in 2027. Original Medicare alone has no cap.
- The average Medigap premium was $217 a month in 2023, and Plan G, the most popular plan, averaged $164.
- Most Medicare Advantage plans require prior approval for some services. In 2024, they denied 7.7% of requests.
- After your first Medigap window, insurers in most states can turn you down or charge more because of your health.
On this page
How each one works
Medicare Advantage (Part C) plans are sold by private insurers approved by Medicare. They cover everything Original Medicare covers, and most include drug coverage and extras like dental, vision and hearing. In exchange, you usually use the plan’s network, and the plan can require prior approval for some care.
Medigap (Medicare Supplement) policies pay some or all of what Original Medicare leaves to you, like the Part A deductible, the 20% Part B coinsurance and hospital copays. Plans are labeled with letters, and every plan with the same letter covers the same things no matter which company sells it. You buy a separate Part D plan for drugs.
You can’t have both at once. For who’s eligible and when to sign up, see who is eligible for Medicare.
Side-by-side
| Medicare Advantage | Original Medicare + Medigap | |
|---|---|---|
| Monthly premium | Often $0 beyond Part B | Medigap premium plus a Part D premium, on top of Part B |
| Doctors and hospitals | Plan’s network, especially in HMOs | Any provider in the U.S. that takes Medicare |
| Prior approval | Required for some services in almost every plan | Rare in Original Medicare |
| Yearly out-of-pocket limit | Yes, up to $9,250 in network in 2026 | No limit in Original Medicare; Medigap fills most gaps |
| Drug coverage | Usually built in | Separate Part D plan |
| Dental, vision and hearing extras | Often included | Not included |
| Care when traveling | Emergencies covered anywhere in the U.S., and urgent care when you’re away from home; routine care mostly in network (PPOs pay something out of network) | Any Medicare provider nationwide; several Medigap plans cover emergencies abroad |
| Switching later | Can switch each fall | Buying Medigap later can mean health questions |
What they cost
Everyone pays the Part B premium, $202.90 a month in 2026, whichever path they choose.
Medicare Advantage. About 75% of people in individual Medicare Advantage plans with drug coverage pay no extra premium. Your costs show up when you get care, through copays and coinsurance, up to the plan’s out-of-pocket limit. The legal maximum is $9,250 in network for 2026, and the average plan set its limit at $5,421. See what is an out-of-pocket maximum.
Medigap. You pay more every month but little when you get care. The average Medigap premium was $217 a month in 2023, ranging from $191 in Alaska to $267 in New York. Plan G averaged $164. Prices depend on your age, where you live and the insurer. A high-deductible version of Plan G has lower premiums but makes you pay up to $2,950 in 2026 before it starts paying.
The Medigap timing trap
You get a one-time, six-month Medigap open enrollment period that starts the month you’re 65 or older and enrolled in Part B. During those six months, insurers have to sell you any Medigap plan they offer at their standard price, whatever your health.
After that window, insurers in most states can ask health questions and turn you down or charge more. That’s why switching from Medicare Advantage back to Original Medicare years later can be hard. There are some exceptions:
- Trial right: if you join Medicare Advantage when you first get Medicare and leave within 12 months, you can buy a Medigap policy without health questions.
- Special situations: you have 63 days to buy certain Medigap plans after events like your Medicare Advantage plan leaving your area.
- State rules: New York and Connecticut let you buy Medigap any time of year. California, Idaho, Illinois, Kentucky, Louisiana, Maryland, Nevada, Oklahoma and Oregon have birthday rules that let you switch to a plan with equal or fewer benefits each year. Minnesota now lets people 65 to 70 buy Medigap without health questions during Medicare open enrollment, once per person.
Who tends to choose which
Medicare Advantage may fit if you:
- Want a low monthly premium and can handle copays when you get care
- Are fine using a network, and your doctors are in it
- Want dental, vision or hearing benefits in the same plan
Medigap may fit if you:
- Want to keep your doctors and see specialists without referrals or approvals
- Spend part of the year in another state
- Have health problems and want predictable costs
- Can afford the higher monthly premium
How to compare
- List your doctors, hospitals and prescriptions.
- Use Medicare’s Plan Finder to compare Medicare Advantage plans, drug plans and Medigap prices in your ZIP code.
- For Medicare Advantage plans, check networks, drug costs, the out-of-pocket limit and star ratings. See what is prior authorization.
- For Medigap, compare prices for the same letter from different insurers, since the benefits are identical.
- Get free, unbiased help from your State Health Insurance Assistance Program.
If you’re already on Medicare, the yearly chance to switch is open enrollment, October 15 to December 7. See Medicare open enrollment. For AARP’s plans, see can I get health insurance through AARP.
Helping a spouse or family member under 65 find coverage? Compare individual plans by ZIP code.
Frequently asked questions
Can I have Medicare Advantage and Medigap at the same time?
No. Medigap only works with Original Medicare. If you join a Medicare Advantage plan, a Medigap policy won’t pay for anything.
Can I switch from Medicare Advantage to Medigap later?
You can switch back to Original Medicare during open enrollment, but in most states a Medigap insurer can then check your health and turn you down, unless you have a trial right, a guaranteed issue right or a state protection.
Which Medigap plan is the most popular?
Plan G. In 2023, 39% of Medigap policyholders had Plan G, 36% had Plan F and 10% had Plan N. Plan F is only sold to people who were eligible for Medicare before 2020.
Is Medicare Advantage cheaper than Medigap?
Usually in monthly premiums. But if you have a costly year, your Medicare Advantage bills can reach thousands of dollars, while a Medigap plan like G leaves you little beyond the Part B deductible.
Sources
- KFF: Medicare Advantage in 2026: Enrollment update and key trends
- KFF: Medicare Advantage in 2026: Premiums, out-of-pocket limits, supplemental benefits and prior authorization
- Medicare.gov: Compare Medigap plan benefits
- KFF: Key facts about Medigap enrollment and premiums
- KFF: Medigap may be elusive for beneficiaries with pre-existing conditions
- KFF: Medicare Advantage insurers made nearly 53 million prior authorization determinations in 2024
This article is general information, not insurance advice, and it isn’t affiliated with Medicare or any insurer. Plan options and prices vary by area. Last reviewed September 2026.