Medigap vs Medicare Advantage: how to choose, with the numbers
A neutral comparison of Original Medicare with Medigap versus Medicare Advantage: costs, networks, prior authorization, travel, and the switching risk.
People new to Medicare face one big structural choice. Either keep Original Medicare and add a Medigap policy plus a Part D drug plan, or replace Original Medicare with a Medicare Advantage (Part C) plan from a private insurer. Neither is better for everyone. They trade cost certainty against flexibility in different ways.
Side by side
| Original Medicare + Medigap + Part D | Medicare Advantage | |
|---|---|---|
| Monthly premiums | Part B + Medigap + Part D | Part B, plus plan premium (often $0) |
| Out-of-pocket costs | Low and predictable (Plan G: Part B deductible only) | Copays and coinsurance up to an annual cap |
| Doctors and hospitals | Any provider nationwide that accepts Medicare | Plan network (HMO/PPO), referrals in many plans |
| Prior authorization | Rare | Common for hospital stays, imaging, procedures |
| Extras | None (separate dental/vision policies) | Often dental, vision, hearing, fitness |
| Travel within the U.S. | Works everywhere | Usually emergencies only outside the area |
| Switching later | Easy to leave for MA | Returning to Medigap may require health questions |
Costs in a bad year
Medigap costs more in premiums every year but caps your spending at almost nothing. Medicare Advantage costs little in a healthy year and more in a sick year, up to the plan's out-of-pocket maximum, which federal rules limit to $9,250 in-network for 2026; many plans set lower caps.
The decision most people miss
The choice is easy to make in one direction and hard in the other. You can leave Medigap for Medicare Advantage during any Open Enrollment. Leaving Medicare Advantage for Medigap later can require medical underwriting in most states, which can mean being declined. Washington is an exception for people already in Medigap (see Washington's switching rule), and the trial right protects first-year enrollees.
Questions to decide
- Do you want any doctor nationwide, or are you happy with a local network?
- Would a sudden $9,250 bill be manageable?
- Do you travel or split the year between states?
- Do you value dental and vision extras enough to accept network rules?
For an independent comparison in Washington, Maru Insurance's Medicare Advantage page and its supplement pages explain both routes.
Questions people ask
Is Medicare Advantage cheaper than Medigap?
Usually in premiums, but out-of-pocket costs can be higher in a year with serious illness.
Can I have both Medigap and Medicare Advantage?
No. Insurers cannot sell you Medigap while you are in an MA plan.
Can I switch from MA back to Medigap?
Yes during enrollment periods, but in most states the Medigap insurer can ask health questions.
Which is better for travel?
Original Medicare with Medigap works anywhere in the U.S.
Independent educational site. Not affiliated with or endorsed by the U.S. government, the federal Medicare program, or any insurance company. Figures are 2026 amounts published by CMS unless noted; check Medicare.gov for your situation.