Medicare·9 min read

Medicare Advantage vs. Medigap: Which Should You Choose?

An honest comparison of Medicare Advantage (Part C) and Medicare Supplement (Medigap) plans — costs, networks, flexibility, and who each one fits.

Key Takeaways

1
Medicare Advantage bundles Part A, B, and usually D into one low- or zero-premium plan, but limits you to a network.
2
Medigap pays the gaps in Original Medicare and lets you see any Medicare-accepting doctor nationwide.
3
Switching from Advantage to Medigap later can be hard — Medigap underwriting can deny you for health reasons in most states.
4
Choose Advantage for low premiums and predictable local care; choose Medigap for travel, flexibility, and minimal out-of-pocket exposure.

The core difference

Medicare Advantage (Part C) replaces Original Medicare. A private carrier — Humana, UnitedHealthcare, Aetna, Kaiser, etc. — administers your Part A, Part B, and usually Part D in one plan, often with extras like dental, vision, and gym memberships. You're locked into the plan's network of doctors and hospitals.

Medigap (Medicare Supplement) works alongside Original Medicare. You keep Parts A and B, then a private carrier sells you a standardized supplement (Plan G, Plan N, etc.) that pays most or all of what Medicare doesn't. You see any doctor in the country who accepts Medicare — no network.

Cost comparison

Medicare Advantage: Many plans have $0 monthly premium beyond the standard Part B premium ($185/month in 2025). You pay copays and coinsurance as you use services, up to a maximum out-of-pocket cap of $9,350/year for in-network care in 2025.

Medigap Plan G (most popular): Monthly premium typically $120–$200 depending on age, ZIP, and carrier, plus a one-time annual Part B deductible ($257 in 2025). After that, Medicare and Plan G together cover virtually everything — your annual exposure is essentially capped at your premium plus the Part B deductible.

Medigap doesn't include drug coverage, so add a standalone Part D plan ($15–$60/month).

Network and travel

Advantage uses HMO or PPO networks. HMOs require referrals and stay in-network for most care; PPOs allow out-of-network care at higher cost. Either way, traveling outside your service area means urgent care only.

Medigap has no network. If a provider accepts Medicare — and 93% of US physicians do — your Medigap plan pays its share. This is the deciding factor for snowbirds, frequent travelers, and anyone with specialists outside their local market.

The switching trap

When you first enroll in Medicare, you have a 6-month Medigap Open Enrollment Period during which carriers must sell you any plan at the standard rate, no health questions asked.

Outside that window, in most states, Medigap carriers can ask health questions and decline coverage. So if you start with a $0 Advantage plan and try to switch to Medigap five years later after a cancer diagnosis, you may be denied. This is the single biggest reason to think long-term about your initial choice.

Who fits each

Advantage is often best if: you're healthy, want low monthly cost, are comfortable with networks, like the bundled extras (dental/vision/gym), and live in an area with strong plan options.

Medigap is often best if: you travel frequently, have or expect significant health needs, want predictable costs, want to keep specific specialists, or value the freedom to see any Medicare provider without referrals.

Frequently Asked

Can I have both Medicare Advantage and Medigap?+

No. Medigap only works with Original Medicare. If you enroll in Advantage, your Medigap policy can't pay anything.

What's the best Medigap plan?+

Plan G is the most comprehensive plan available to new enrollees in 2026 — it covers everything except the Part B deductible. Plan N is a slightly cheaper alternative with small copays.

Can I switch between Advantage and Medigap each year?+

You can leave Advantage during the Annual Enrollment Period (Oct 15–Dec 7) or the Medicare Advantage Open Enrollment Period (Jan 1–Mar 31) and return to Original Medicare. Adding Medigap, however, requires medical underwriting in most states.

Source: Medicare.gov plan finder ↗

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