Every fall, your mailbox fills up with promises.
The ads make Medicare Advantage sound like the deal of the century, and for some people it genuinely is.
But there's a second option that gets almost no airtime, and the difference between the two can end up costing you thousands.
Original Medicare pays about 80% of covered costs.
A Medicare Supplement plan, often called Medigap, picks up most of the rest.
You can see any doctor nationwide who takes Medicare, no referrals, no networks.
The tradeoff is the monthly premium, which can run well over $100 depending on your age and where you live.
The government pays a private insurer to cover you, and that insurer decides what's covered and how.
Many plans advertise $0 premiums because they're funded by that federal payment, not because care is free.
You still pay copays, coinsurance, and often an annual out-of-pocket maximum that can climb past $8,000 in-network.
Here's the part that rarely makes the commercial.
A hospital or specialist you've seen for years may be in-network this year and out next year.
Prior authorization is common, meaning the plan can review whether it will cover a service before you get it.
A 2023 federal report found that some denials were later overturned on appeal, which tells you something about how often the first answer isn't the final one.
The pitch is strongest for healthy people.
If you're 65, take one cheap generic, and rarely see a doctor, an Advantage plan with a $0 premium and a dental allowance can genuinely save you money.
The average 65-year-old is not the average 80-year-old.
If you develop cancer, need a specialist, or end up in a nursing facility, the plan's rules and networks matter more than the premium ever did.
In most states, Medigap insurers can reject you or charge more based on your health once you're past your initial enrollment window.
That fine print is where the real risk hides.
People who choose Advantage at 65 and want out at 75 may find the door partially closed, depending on their state.
A handful of states, including New York and Connecticut, offer more flexibility, but most don't.
So who benefits from the advertising blitz?
Insurers, who receive a set payment per member and profit when care costs less than that payment.
That doesn't make them villains, but it does mean the incentives aren't perfectly aligned with yours.
The quieter option, Medigap, has less marketing budget because the math is simpler and the margins are thinner.
Check whether your doctors are in-network for any Advantage plan you're considering.
Read the formulary for your specific prescriptions, not just the ad's "dental, vision, hearing" checklist.
And look up your state's rules on switching from Advantage to Medigap later, because that's the decision you can't easily undo.
None of this means Advantage plans are bad.
It means the shiny brochure and the actual coverage are two different documents, and only one of them will show up when you need care. **Our take:** The right answer depends on your health, your budget, and your tolerance for rules, not on which ad you saw last.
Final Thoughts
Spend an hour with the plan's actual evidence of coverage before you enroll, because the premium is the easy part and the network is the part that bites.