"Medicare Advantage" isn't one product — it's a category. The plan type changes how the client accesses care day to day.
Health Maintenance Organization
In-network care only (except emergencies). Usually requires a primary care provider and referrals to see specialists. Typically the lowest cost structure.
Preferred Provider Organization
Can go out-of-network at a higher cost. Referrals usually not required. More flexibility, often a higher premium or cost-share.
HMO with Point-of-Service
An HMO with a limited allowance to go out-of-network for specific services — a middle ground between HMO and PPO.
Special Needs Plan
Restricted to a specific population — dual-eligible or a qualifying chronic condition. Same HMO/PPO-style network rules underneath, plus tailored benefits. Full breakdown in Module 06.