Medicare Advantage

Core Takeaways

• It replaces Original Medicare rather than supplementing it, and you remain in it until you actively leave.
• Every plan must cap in-network out-of-pocket spending; CMS set the 2026 ceiling at $9,250 in-network and $13,900 combined.
• Networks and service areas are the price of the extra benefits. Care outside them costs more or is not covered.
• Returning to Original Medicare is straightforward; buying a Medigap supplement afterwards is not, because most states allow underwriting at that point.

What is Medicare Advantage?

In plain English: Original Medicare is one national fee-for-service programme. Medicare Advantage is a set of private plans that are paid by the government to deliver the same core benefits, and given room to add extras and to manage care through a network. The government sets the floor; the insurer designs everything above it.

The plans are usually structured as an HMO or a PPO. An HMO generally requires you to stay in network and often to route specialist referrals through a primary care physician. A PPO lets you go outside the network at higher cost. The distinction matters more in Medicare than in employer coverage, because the population using it sees specialists more often.

Medicare Advantage vs Original Medicare

	Medicare Advantage	Original Medicare
Administered by	Private insurer under federal contract	Federal government
Core benefits	Must cover at least Part A and Part B	Part A hospital, Part B outpatient
Drug coverage	Usually included	Requires a separate Part D plan
Dental, vision, hearing	Commonly included	Not covered
Provider access	Network and service area	Nationwide, any provider accepting Medicare
Referrals	Often required	Not required
Annual out-of-pocket cap	Required by law	None, unless a Medigap policy or employer plan applies
Extra paperwork	Less, because the plan administers claims	More, with separate Part D and supplement

The last two rows are the real trade. Advantage plans cap your annual exposure, which Original Medicare alone does not. Original Medicare gives you nationwide access with no network, which Advantage plans do not.

What the Enrolment Decision Turns On

Where you live, and where you might live. Plans are sold by county. A plan that fits your current address may not be available after a move, and moving out of a service area is one of the events that opens a special enrolment period.

Which providers you need. Check the specific doctors and hospitals, not the network’s marketing name. Networks change between plan years, and a provider who is in network at enrolment may not be at renewal.

Which drugs you take. Formularies are plan-specific and tiered. A drug covered at a low tier in one plan can sit at a specialty tier in another, and the difference over a year can exceed the premium difference many times over.

How much care you expect to use. The annual out-of-pocket cap is the strongest argument for the structure, and it is worth most to someone with predictable, ongoing medical need. Someone who is healthy and travels extensively may value the absence of a network more.

The Asymmetry Worth Knowing Before You Switch

Joining a Medicare Advantage plan for the first time is a straightforward transaction. Leaving one later is not.

Once the initial enrolment period has passed, most states permit Medigap insurers to underwrite applications. Underwriting means health questions, and health questions mean that a condition developed since enrolment can lead to a higher premium or a refusal. A person who moves to Medicare Advantage at 65 while healthy, and develops a chronic condition at 72, may find that returning to Original Medicare with a supplement is no longer available on standard terms.

That does not make Medicare Advantage the wrong choice. It does mean the decision should be made as though it were less reversible than it is, because for many people it becomes so.