When you have Medicare, one of the biggest choices you make is how to fill the gaps in Original Medicare. Most people choose between two routes: a Medicare Advantage plan, which replaces Original Medicare with a private plan, or Original Medicare paired with a Medicare Supplement policy, usually called Medigap. Both can work well. They suit different people, and the switching rules mean the choice is harder to undo than many people expect.
This guide compares the two side by side, explains what each costs and covers in 2027, and walks through the rules that catch people out. It is general information, not advice about a specific plan. For official details, use Medicare.gov or call 1-800-MEDICARE.
The short answer
Medicare Advantage usually has lower monthly premiums and often includes extras such as drug coverage and some dental or vision benefits, but you generally use a provider network and pay copays as you go, up to a yearly limit. Medigap usually costs more each month, but it lets you see any doctor in the country who accepts Medicare and can leave you with very little to pay when you get care. The right choice depends on your budget, your health, your doctors and how much you travel.
How the two options work
Medicare Advantage (Part C) is offered by private insurers approved by Medicare. It covers everything Original Medicare covers, and most plans also include Part D drug coverage. You still pay your Part B premium, plus any plan premium. Most plans are HMOs or PPOs, which means you get the lowest costs, or any coverage at all, when you use doctors and hospitals in the plan’s network.
Medigap is a supplemental policy you buy on top of Original Medicare. It helps pay costs Original Medicare leaves behind, such as deductibles, copays and coinsurance. Medigap plans are standardized and labeled by letter, so a Plan G from one insurer offers the same basic benefits as a Plan G from another. The price is what differs. Medigap does not include drug coverage, so most people with Medigap also buy a separate Part D plan.
Side-by-side comparison
| Feature | Medicare Advantage | Original Medicare + Medigap |
|---|---|---|
| Monthly premium | Often low, and some plans charge $0 beyond the Part B premium | Usually higher; varies by plan letter, age, location and insurer |
| Doctors and hospitals | Usually a network (HMO or PPO) | Any provider in the U.S. that accepts Medicare |
| Costs when you get care | Copays and coinsurance, capped by a yearly out-of-pocket limit | Often low or predictable, depending on the plan letter |
| Yearly out-of-pocket limit | Required; up to $9,850 in-network in 2027 | Original Medicare has no cap; Medigap fills most gaps |
| Drug coverage | Usually included | Buy a separate Part D plan |
| Extras (dental, vision, hearing) | Often included, with limits | Not included |
| Prior authorization | Common for some services | Rare under Original Medicare |
| Travel within the U.S. | Limited outside the network, except emergencies | Coverage anywhere in the U.S. |
What the costs look like in 2027
Every Medicare Advantage plan must cap what you pay for covered medical services each year. For 2027, CMS set the maximum in-network out-of-pocket limit at $9,850, up from $9,250 in 2026. For PPO plans, the combined limit for in-network and out-of-network care is $14,800. Many plans set their own limits lower than these maximums, so check each plan’s figure.
Drug costs also have a ceiling. In 2027, the most anyone pays out of pocket for covered Part D drugs is $2,400 for the year, whether the coverage comes through a Medicare Advantage plan or a stand-alone Part D plan used alongside Medigap.
Medigap premiums vary widely by plan letter, state, age and insurer, and some insurers raise premiums as you get older. Because the benefits for each letter are standardized, comparing the same letter across insurers is a fair price comparison.
Example: A 67-year-old in good health sees a family doctor twice a year and rarely travels. A Medicare Advantage plan with a low premium and her doctor in its network may cost her far less over a typical year. Her neighbor has a heart condition, sees specialists at a university hospital outside the local plans’ networks and spends winters in another state. For him, the higher Medigap premium may be worth it because he can see any provider that accepts Medicare and his costs stay predictable.
The switching rule that catches people out
The most important difference is not cost. It is how hard it can be to move from Medicare Advantage to Medigap later.
Your Medigap Open Enrollment Period is a one-time, six-month window that starts the first month you have Part B and are 65 or older. During that window, insurers must sell you any Medigap policy they offer and cannot use your health to deny you or charge more. It does not repeat every year.
After that window, in most states, insurers can use medical underwriting. That means if you develop health problems while in a Medicare Advantage plan and later want to return to Original Medicare with Medigap, an insurer may refuse to sell you a policy or charge more. Some situations give you guaranteed issue rights, and federal rules include a trial right for some people who join Medicare Advantage for the first time and leave within a year. A few states also offer broader protections. Check your State Health Insurance Assistance Program or state insurance department before relying on any of these.
Example: Someone joins a Medicare Advantage plan at 65 to save on premiums. At 72, after a cancer diagnosis, she wants to see a specialist outside her network and tries to switch to Original Medicare with Medigap. Outside her protected windows, Medigap insurers in her state can ask health questions and may decline her. Thinking about this risk at 65 is far easier than discovering it later.
How to choose: a step-by-step check
- List your doctors, hospitals and prescriptions. Write down every provider and drug you want to keep.
- Check networks. For each Medicare Advantage plan, confirm with your doctors’ offices that they are in network for 2027.
- Compare total yearly costs. Add premiums, deductibles and likely copays, then compare against the plan’s out-of-pocket limit. Use the Medicare Plan Finder for drug costs.
- Think about travel. If you spend long periods away from home, check out-of-network and travel coverage carefully.
- Check your Medigap timing. Find out whether you are still in your Medigap Open Enrollment Period or have a guaranteed issue right.
- Get free, unbiased help. Your SHIP offers free one-on-one counseling and does not sell insurance.
Who each option tends to suit
Medicare Advantage often suits people who want lower premiums, are comfortable using a network, like having drug and extra benefits in one plan and live where strong local plans are available. Medigap often suits people who want freedom to see any provider, have ongoing health conditions or expect to need specialists, travel or live in more than one state, and prefer predictable costs over lower premiums.
Neither is automatically better. The best choice is the one that fits your doctors, budget and health, now and as those things change.
Avoid pressure and misleading ads
Medicare marketing is heavy in the fall. Be cautious with ads promising “extra benefits” or cash back if you call now, and with anyone who claims to be from Medicare. Medicare does not call to sell plans. If you work with an agent or broker, ask which companies they represent, since many are paid by the plans they sell and may not show every option in your area.
Common questions
Can I have Medicare Advantage and Medigap at the same time
No. Medigap only works with Original Medicare. It is illegal for anyone to sell you a Medigap policy if they know you are in a Medicare Advantage plan, unless you are switching back to Original Medicare.
Is Medicare Advantage cheaper than Medigap
Premiums are usually lower, but total costs depend on how much care you use. A healthy person may pay less with Medicare Advantage, while someone who needs a lot of care may pay less overall with Medigap.
What is the 2027 Medicare Advantage out-of-pocket maximum
CMS set the in-network maximum at $9,850 for 2027, with a combined in-network and out-of-network limit of $14,800 for PPO plans. Many plans set lower limits.
When can I switch between them
You can change Medicare Advantage plans or return to Original Medicare during Open Enrollment, October 15 to December 7, and Medicare Advantage members get another chance from January 1 to March 31. Buying Medigap outside protected windows may involve health questions in most states.
Before you decide
Start with your doctors, prescriptions and travel habits, then compare total yearly costs rather than premiums alone. Pay close attention to Medigap timing, because the choice you make when you first get Medicare can shape your options for years. Use free SHIP counseling if you want a second opinion.
Editorial note: This article is general information and is not affiliated with or endorsed by the U.S. government or the federal Medicare program. It is not insurance advice and does not recommend any plan. 2027 limits come from CMS contract year 2027 guidance. For official information, visit Medicare.gov or call 1-800-MEDICARE.