Every fall, millions of Americans on Medicare face the same confusing fork in the road.
One path is Medicare Advantage, a bundled plan run by private insurers that often comes with a $0 premium.
The other is Original Medicare paired with a Medigap supplement, which can run $100 to $200 a month or more.
The sticker price makes Advantage look like the obvious winner, but that low premium is hiding something.
The math flips fast once you actually use your coverage.
Medicare Advantage plans lure people in with extras: dental, vision, hearing aids, gym memberships, even grocery allowances.
What they don't advertise as loudly is the out-of-pocket maximum, which can hit $8,850 for in-network care in 2025, and higher if you go out of network.
Copays pile up every time you see a specialist, get a scan, or spend a night in the hospital.
A serious diagnosis can turn those "free" extras into a very expensive year.
Original Medicare with a Medigap Plan G works differently.
You pay a monthly premium, but once you hit the deductible, the supplement covers most of what Medicare doesn't.
You can see any doctor in the country who accepts Medicare.
For snowbirds or anyone who travels, that flexibility is hard to put a price on.
The catch is that Medigap isn't guaranteed forever.
If you don't sign up during your initial enrollment window, insurers in most states can deny you or charge more based on your health history.
Miss that window and you may be locked out of the plan you actually want.
You can switch back to Original Medicare during open enrollment, but in most states you can't easily buy a Medigap policy afterward.
Insurers can reject you for pre-existing conditions.
That's why financial planners often tell healthy 65-year-olds to grab Medigap while they still can.
Here's the part nobody mentions at the sales seminar.
Medicare Advantage plans are paid a set amount per member, so they profit by keeping costs down.
That can mean prior authorizations, narrow networks, and denials for care your doctor recommends.
A 2023 government report found some plans denied requests that should have been approved.
If you're fighting a denial while sick, the savings evaporate.
If you're healthy, rarely see doctors, and want low premiums with some extras, Advantage can work.
If you have chronic conditions, travel, or simply want predictable costs and open access to providers, Medigap often wins despite the higher monthly bill.
The smartest move is to run your own numbers before you decide.
Add up premiums plus worst-case out-of-pocket costs for both paths.
Then ask yourself which risk you can live with.
Our take: the $0 premium is a marketing hook, not a free lunch.
For most people who can afford it, locking in a Medigap plan early buys peace of mind that's worth more than the monthly savings.
Final Thoughts
Just don't wait until you're sick to find out you can't get one.