Every fall, your mailbox fills with promises.
One envelope says you can get dental, vision, and a gym membership for a $0 monthly premium.
Another warns that without a Medigap policy, you could be one hospital stay away from financial ruin.
Both can't be telling the whole story, because they're selling two very different products.
Here's the part the ads skip: Medicare Advantage and Medicare Supplement aren't really competitors.
They're opposite bets on how you want to pay for care.
Medicare Advantage is run by private insurers that contract with the government.
You typically stay in a network, get extra perks, and pay copays as you go.
The trade-off is that costs can show up when you're sickest.
A 2024 KFF analysis found that enrollees in traditional Medicare with no supplement spent far less on premiums but faced uncapped out-of-pocket exposure.
Advantage plans do cap yearly spending, but those caps can run into the thousands.
Medicare Supplement, often called Medigap, works the other way.
You pay a monthly premium, sometimes $150 to $250 or more depending on your state and age, and the policy picks up most of what original Medicare doesn't.
The catch is that premium never goes away, and it usually rises over time.
The pitchmen on both sides have incentives.
Advantage plans are heavily marketed because insurers earn more when they enroll you, and the government pays them a set amount per member.
That's why you see ads with celebrities and freebie offers.
Medigap agents earn commissions too, often a percentage of that higher monthly premium.
If you're generally healthy, take few prescriptions, and want a low monthly cost, Advantage can look appealing, especially with the extra benefits.
If you have chronic conditions, travel a lot, or want predictable costs and full provider access, Medigap tends to win on peace of mind, if you can afford the premium.
In most states, you have a one-time guaranteed right to buy a Medigap policy when you first enroll in Medicare at 65.
After that window, insurers in most states can deny you or charge more based on health history.
Switching later isn't a simple menu choice, and that asymmetry is exactly why the sales scripts lean so hard.
Read the plan's actual out-of-pocket maximum, not the brochure.
Check whether your doctors and hospitals are in network.
Add up your prescriptions under each plan's formulary.
Then decide which risk you'd rather carry: a steady premium or a bill that arrives when you're already dealing with something worse.
The honest answer is that neither option is universally better, and anyone who tells you otherwise is probably getting paid to say it.
Final Thoughts
The real question isn't which plan is cheapest today, but which one you can still afford and use on your worst day.