If you're turning 65 this year, your mailbox is probably stuffed with promises.
One pile says you can get dental, vision, and groceries bundled into a Medicare Advantage plan for a $0 premium.
Another says a Medicare Supplement, also called Medigap, will keep your doctor and your budget predictable for life.
They are also very different animals, and picking wrong can cost you real money.
Original Medicare pays about 80% of most covered costs.
A Medigap supplement plugs most of that gap.
You pay a monthly premium, often $100 to $200 depending on your state and plan letter, but your out-of-pocket costs stay low and predictable.
Any doctor who takes Medicare generally takes you.
The government pays a private insurer to run your coverage.
You usually keep the same Part B premium, and many plans advertise a $0 monthly premium on top.
In exchange, you accept a network, prior authorizations, and copays that can add up fast.
Plans often throw in extras like hearing aids, gym memberships, and an over-the-counter allowance.
The catch: you can face thousands in copays if you get seriously sick.
A supplement with a $150 monthly premium runs about $1,800 a year.
A $0 premium Advantage plan sounds free until you land in the hospital.
Advantage plans cap out-of-pocket spending, but those caps commonly run $4,000 to $8,000 per year, and some services like certain hospital stays can cost hundreds per day before you hit the limit.
For healthy people, Advantage often wins on price.
For anyone with ongoing conditions, supplements often win on total cost.
There's another trap that doesn't get enough attention.
With a Medigap plan, you can usually switch plans or move to Advantage later without answering health questions, as long as you act during your one-time Medigap open enrollment window, which starts the month you're 65 and enrolled in Part B.
Miss it, and insurers in most states can charge you more or reject you outright based on your health history.
A few states, including New York and Connecticut, have year-round protections, but most don't.
Advantage plans do let you switch back to Original Medicare during the annual Medicare Open Enrollment window each fall.
The problem is getting a supplement afterward.
If you've developed a condition like diabetes, heart disease, or cancer, you may be priced out or turned down.
That's the risk people don't see coming when they sign up for the cheaper plan at 65.
First, add up your actual medications and doctors, not the ones you hope to have.
Second, check whether your physicians are in the Advantage plan's network.
Third, look at the plan's annual out-of-pocket maximum, not the monthly premium.
Fourth, think about your health ten years from now, not just today.
One more thing: compare total yearly costs, not just the sticker price.
A plan that saves you $1,800 in premiums but costs you $5,000 in a bad year is not a bargain.
My take: the $0 premium pitch is marketing, not math.
If you can afford the monthly cost and want fewer surprises, a supplement is often the safer long-term bet.
Final Thoughts
But if money is tight and you're healthy, an Advantage plan can work, as long as you understand exactly what you're giving up.