Medicare Advantage, explained.

Medicare Advantage, also called Part C, is a private plan that takes the place of Original Medicare. It has to cover everything Parts A and B cover, and most plans bundle in dental, vision, hearing, and a drug plan, often for a very low or zero monthly premium (you still pay your Part B premium). In exchange for that low premium, you accept a provider network, prior authorization on a lot of services, and a benefit package that can change every January. As of early 2026, about 35 million people, roughly 55% of everyone eligible for Medicare, are on an Advantage plan. It fits some people well and badly burns others, and the deciding factors are usually your health, your doctors, and how much you travel, not the premium. Apex Health Advisors does not sell Medicare Advantage plans. This page is here to explain how it actually works so you can compare options on Medicare.gov or by calling 1-800-MEDICARE.

How Part C actually works

Original Medicare is the government program: Part A for hospital, Part B for doctors and outpatient. Medicare Advantage is the private alternative. You sign over the way you receive your benefits to an insurance company, and that company administers your care under rules Medicare sets. You keep paying your Part B premium every month, and the Advantage plan layers its own premium (often $0), copays, and rules on top.

The part people miss is that this is not extra coverage stacked on Original Medicare. It is a swap. You cannot run an Advantage plan and a Medigap policy at the same time. They are two different ways of doing the same job, and choosing one means giving up the other.

The 2026 numbers worth knowing

A few figures frame the real tradeoff this year. The average Advantage premium is around $14 a month, and plenty of plans are still $0. A Medigap Plan G for a 65-year-old typically runs somewhere in the $180 to $250 range depending on where you live and which insurer. That monthly gap is real, and it is why Advantage looks so attractive on paper.

Then there is the out-of-pocket maximum. In 2026 the in-network cap on Advantage plans cannot exceed $9,250 for covered Part A and B services, and individual plans can set it lower. Original Medicare has no out-of-pocket ceiling at all, which is exactly why most people who keep Original Medicare pair it with a Medigap policy. So the comparison is not free versus expensive. It is a low fixed cost with a high possible ceiling versus a higher fixed cost with a predictable floor.

The three things that trip people up

I have watched the same three problems play out over and over. The network: a large share of Advantage enrollees are in HMO-style plans that pay nothing out of network. If you snowbird in two states, travel a lot, or need a specialist who is not contracted, you can get stuck with the full bill. Prior authorization: nearly all enrollees are in plans that require it for at least some services. Insurers made close to 50 million prior authorization determinations in 2023 and fully or partially denied about 3.2 million of them, roughly 6.4%. A federal rule phasing in over 2026 and 2027 tightens decision timelines (7 days for standard requests, 72 hours for expedited ones) but it does not make denials go away. And yearly change: formularies, networks, copays, and the extra benefits can all shift every January. The plan that covered your oncologist this year may drop him next year.

One Arizona note. Starting in 2026, Arizona is one of six states where CMS is running the WISeR pilot, which brings prior authorization into Original Medicare for a short list of select services (things like certain spine procedures, nerve treatments, and skin substitutes). So if you are an AZ reader assuming Original Medicare is hassle-free on every service, that is changing in a limited way here.

The switching trap, and why it matters most

This is the single most expensive mistake I see, so I will be blunt about it. When you turn 65 and enroll in Part B, you get a 6-month window where you can buy any Medigap policy with no medical underwriting. In most states, insurers cannot deny you or charge you more for your health during that window. That window does not come back.

What that means in practice: a healthy 65-year-old picks a $0 Advantage plan, feels fine for years, then gets a cancer diagnosis at 72 and tries to move to Medigap for the cost predictability. Outside that original window, the Medigap insurer can look at the cancer history and decline the application or price it out of reach. People assume they can flip back to Medigap whenever they want. In most states, they cannot. Choose with that one-way door in mind.

Who tends to be happy on each side

Advantage tends to work for someone who is relatively healthy, has a primary care doctor already in the plan's network, does not travel much, likes the bundled dental/vision/hearing extras, and can absorb a rough year of cost sharing without it hurting. The low premium is a genuine win for that profile.

• Medigap tends to fit someone managing a chronic condition, who travels or splits time between states, who wants to use any provider in the country that takes Medicare, or for whom a predictable monthly cost matters more than saving on the premium.
• And a timely 2026 wrinkle: roughly 1 in 10 Advantage enrollees, about 2.9 million people, were pushed into a plan change this year because their plan exited or trimmed its footprint. When a plan leaves and you are defaulted back to Original Medicare with no Medigap, you are exposed to costs with no ceiling. Plan stability has become a real reason some people lean Medigap right now.

Where to compare plans (and our role)

If you want to look at actual Advantage plans in your ZIP code, the authoritative tool is the Plan Finder at Medicare.gov, or you can call 1-800-MEDICARE (1-800-633-4227), which is open 24/7. That is where you compare premiums, networks, drug formularies, and star ratings side by side for plans available to you.

Apex Health Advisors is not connected with or endorsed by the U.S. government or the federal Medicare program. We do not sell Medicare Advantage plans, and nothing here is a recommendation of any specific plan. We do place Medicare Supplement (Medigap) coverage, so if your reading lands you on the Medigap side of this decision, we are glad to talk it through. Either way, the goal is that you walk into the choice understanding the one-way door before you pick a side. Questions: 623-292-4360.

Apex Health Advisors is not connected with or endorsed by the U.S. government or the federal Medicare program. This page is educational only. We do not sell Medicare Advantage plans. To compare plans, visit Medicare.gov or call 1-800-MEDICARE (1-800-633-4227).