Medicare Advantage does not replace Original Medicare. CMS requires every Medicare Advantage plan to cover at least what Parts A and B cover, delivered through a private insurer CMS has contracted and approved. The plan becomes the mechanism for Medicare benefit delivery, not a substitute for it.
- Medicare Advantage plans are sold by private insurers approved by Medicare and must renew their contracts with CMS annually.
- Most plans bundle Part D prescription drug coverage, so a separate Part D policy is unnecessary.
- Enrollees still pay the standard Medicare Part B premium ($202.90/month in 2026, per CMS) in addition to any plan premium.
- Plans set their own copays and coinsurance within CMS guardrails, so cost-sharing varies across plans.
- Networks vary by plan type: HMO plans require in-network providers only, while PPO plans allow out-of-network care at higher cost.



