Medicare Advantage vs Medigap: The Side-by-Side Decision File
This is the central decision of retirement healthcare, and it is a fork you choose once: a private network plan with a capped but real cost-sharing, versus Original Medicare wrapped in a supplement with near-zero cost-sharing and no network. This file puts every decision-relevant dimension side by side.
| Dimension | Medicare Advantage | Medigap (G as benchmark) |
|---|---|---|
| Fixed monthly cost | $0 plan premium + $185 Part B | $120–170 G premium + $185 Part B |
| Variable cost ceiling | $9,350/yr in-network max (2025 federal) | ≈ $257 (Part B deductible) |
| Doctor choice | Network only; HMO needs referrals | Any provider accepting Medicare |
| Prior authorization | Common for imaging, surgery, drugs | Not applicable |
| Drug coverage | Usually bundled | Separate Part D policy |
| Stability year to year | Copays/networks can change every January | Benefits fixed by law; premiums drift up |
| Switching out later | Limited GI windows to Medigap | Underwriting applies (most states) |
The asymmetry that decides most cases
The exit doors are not equal. Moving from Advantage to Medigap later generally requires passing medical underwriting outside guaranteed-issue windows — and people often try to leave Advantage precisely because they got sick, when underwriting is hardest. Moving from Medigap to Advantage is always possible. This asymmetry means the healthy 65-year-old choosing Advantage is making a choice that is easy to enter and hard to reverse.
Scoring your own case
Advantage fits: tight budgets today, robust local networks for your specific providers, willingness to manage authorizations, and short travel horizons. Medigap fits: chronic conditions, specialist-heavy care, snowbirds and travelers, and anyone who values benefit stability over premium. The honest tiebreaker for borderline cases is provider verification — if your doctors are in-network and you rarely travel, MA’s $100+/month saving compounds to real money over a decade.
FAQ
Which is cheaper over 20 years?
For consistently healthy people, MA often wins on raw dollars. For anyone with chronic conditions or heavy utilization, Medigap’s near-zero cost-sharing wins — the crossover depends entirely on your claim history.
Can I switch from MA to Medigap in the first year?
Yes — the 12-month trial right lets you leave MA and use guaranteed issue into a Medigap plan. Some states extend this beyond the federal floor.
Does Medigap cover things MA does not?
Coverage is different, not larger: MA plans must at least match Original Medicare and often add dental/vision, while Medigap offers national provider freedom instead.
Related reading: What is MA · When MA wins · Plan G benchmark · Part D mechanics