Every fall, mailboxes across America fill up with glossy promises about Medicare plans that cost "$0 premium" and include dental, vision, and gym memberships.
What the brochures rarely mention is what happens when you actually get sick.
The choice between Medicare Advantage and a Medicare Supplement plan isn't really about premiums.
It's about who absorbs the risk when your health takes a turn.
Original Medicare pays roughly 80% of covered costs, and you're on the hook for the rest with no cap.
A Medigap supplement picks up most of that gap, but you pay a monthly premium for the privilege — often $100 to $250 depending on your state and age.
Medicare Advantage, by contrast, replaces Original Medicare with a private insurer's network, usually for a low or zero premium, but you accept copays, prior authorizations, and a limited provider list.
That last part is where the trouble lives.
A 2023 report from the HHS Office of Inspector General found that some Medicare Advantage plans denied prior authorization requests that met Medicare's own coverage rules.
Denials get reversed on appeal more often than you'd expect, but only if you have the stamina to fight.
The premium math is also more slippery than it looks.
Advantage plans advertise low monthly costs, then charge you per doctor visit, per specialist, per hospital stay, per day.
A supplement's premium feels painful every month until you're the one staring down a $3,000 hospital bill.
Neither option is universally cheaper — it depends on how much care you actually use, which is the one thing nobody can predict.
In most states, you can be turned down for a Medigap plan or charged more based on your health history if you apply after your initial enrollment window.
If you start with Advantage and later want to switch, you may find yourself medically stranded.
A handful of states offer year-round guaranteed enrollment, but most don't.
The insurers selling both products, and the brokers earning commissions that differ depending on which one you pick.
That's not a conspiracy — it's just how the incentives line up.
Ask any broker whether their advice changes based on commission, and watch how carefully they answer.
What actually helps: read your plan's formulary and provider directory before enrolling, not after.
Call your doctors and ask which plans they accept.
Check whether your prescriptions are covered at a tier you can afford.
And if you have ongoing health conditions, price out a supplement even if the premium stings.
Our take: the "$0 premium" pitch is a marketing device, not a financial plan.
For healthy people with low medical needs, Advantage can work fine — but for anyone managing chronic conditions, the flexibility of a supplement is often worth the monthly cost.
Final Thoughts
The real question isn't which plan is cheaper today; it's which one leaves you with options when you need them most.