What Is Medicare Advantage (Part C)? A Plain-English File
Medicare Advantage (Part C) is a private all-in-one alternative to Original Medicare: the plan bundles Part A hospital, Part B medical, and almost always Part D drugs into a single policy, usually with a $0 monthly premium and a provider network. It is not a supplement — it replaces Original Medicare as your claims processor.
| Feature | Medicare Advantage | Original Medicare + Medigap |
|---|---|---|
| Monthly premium | Often $0 (beyond Part B) | Medigap premium $50–200 + Part B |
| Provider network | HMO/PPO networks, referrals (HMO) | Any provider taking Medicare nationwide |
| Cost sharing | Copays/coinsurance with an OOP max | Near-zero after premiums (Plan G/N) |
| Out-of-pocket ceiling 2025 | $9,350 in-network max (plans may be lower) | Effectively $0 on G; N adds only copays |
| Prior authorization | Extensive — plans manage utilization | Rare — Medicare rules only |
| Drug coverage | Bundled (most plans) | Separate Part D policy |
The structural trade you are making
Advantage trades unlimited provider access and simple cost-sharing for a lower headline premium and an out-of-pocket ceiling. Original Medicare + Medigap has no network and no meaningful cost-sharing but costs $100+ monthly forever. Advantage caps your worst year (the $9,350 federal in-network maximum, often lower) but inserts prior authorization, network boundaries and annual plan changes between you and your care. Neither is objectively better — they are opposite risk shapes.
The mechanics people miss
Three details drive most Advantage regret: network geography (an HMO that covers your home county may strand you traveling), formulary churn (plans can drop drugs annually), and the annual plan-shuffle (carriers change copays and networks each fall for the next year). Medigap never changes benefits — standardization is federal — which is why the comparison is really about predictability versus premium.
FAQ
Do I still pay the Part B premium on Advantage?
Yes — you always pay Medicare Part B ($185/month standard 2025) whether you choose Advantage or Medigap.
Can I have Medicare Advantage and Medigap together?
No — it is one or the other. Medigap supplements Original Medicare only, and federal rules bar selling one to C/D enrollees.
Is $0 premium Advantage really free?
No — you pay the Part B premium, plan copays, and accept network limits. ‘Free’ refers only to the plan’s own premium.
Related reading: MA vs Medigap decision file · HMO vs PPO · When MA wins · Medigap plans