Glossy envelopes promise a Medicare Advantage plan with a $0 monthly premium, free dental, a flex card for groceries, even money back on your Part B bill.
It sounds like the deal of a lifetime, and that is exactly the problem.
Here's what those ads leave out: the premium is not the price.
In Medicare Advantage, you generally stay inside the plan's network and play by its rules.
In traditional Medicare paired with a Medigap supplement, you can see almost any provider nationwide who accepts Medicare, and you rarely deal with prior authorization for routine care.
A Medigap Plan G for a 65-year-old often runs $120 to $180 a month, depending on your state, plus the standard Part B premium, which is $185 in 2025.
Advantage plans can be nearly free each month, but cost-sharing shows up later — a hospital stay, a scan, a specialist visit, or a drug that lands in a pricey tier.
The math depends entirely on your health and your bank account.
If you are healthy, take few prescriptions, and want to keep monthly costs low, an Advantage plan can pencil out.
If you have chronic conditions, travel a lot, or want predictable bills, the supplement route often wins, because it caps what you pay after Medicare's share.
The catch that trips people up most is timing.
In most states, you get a one-time window to buy a Medigap policy without answering health questions, starting when you first enroll in Part B.
Miss it, and insurers in most states can charge you more or reject you outright.
Meanwhile, you can often switch into an Advantage plan during the annual enrollment window with no health screening at all.
Insurance companies benefit when healthy seniors pick Advantage plans and sicker ones stay put or get locked out of supplements.
Brokers benefit when they steer you toward plans that pay them the highest commission, which is not always the plan that fits you best.
And the federal government pays Advantage insurers a set amount per member, which gives them a financial incentive to manage your care tightly.
So before you shred another envelope, do three things.
Check whether your doctors and hospitals are actually in the network, not just "in network" on paper.
Add up the worst-case out-of-pocket maximum, not the best-case premium.
And read the drug formulary, because a single medication can swing your annual cost by thousands.
None of this means Advantage plans are a scam, and none of it means supplements are always worth it.
It means the "$0 premium" headline is marketing, not math.
My take: the plan that saves you money is the one that matches your actual doctors, drugs, and health, not the one with the fanciest mailer.
Final Thoughts
Run your own numbers before you trust anyone's pitch, including mine.