If you're turning 65 this year, you're about to make one of the most expensive decisions of your retirement — and most people rush it in a single afternoon.
The two main paths are Medicare Advantage (Part C) and Medicare Supplement plans, also called Medigap.
They behave nothing alike when a real medical bill shows up.
Medicare Advantage works like an HMO or PPO you may already know from a job.
A private insurer bundles your hospital, doctor, and drug coverage into one plan, often with a $0 monthly premium and extras like dental, vision, or gym memberships.
The trade-off hides in the details: deductibles, copays, and a yearly out-of-pocket maximum that can run past $8,000 for in-network care.
You generally stay inside the plan's network, and you may need referrals to see a specialist.
You keep original Medicare and buy a supplement that picks up most of what Medicare doesn't — sometimes nearly all of it.
Premiums run higher, often $100 to $250 a month depending on your state and plan letter.
In exchange, you can see almost any provider in the country who accepts Medicare, and there are no networks or referrals.
Many plans leave you with little beyond the standard Part B deductible.
If you're healthy and rarely see a doctor, a $0-premium Advantage plan can look like free money.
But one bad year — a surgery, a cancer diagnosis, a hospital stay — can flip that equation fast.
Advantage enrollees can face daily hospital copays and per-visit charges that add up quickly, while Medigap holders often pay a predictable monthly bill and little else.
There's a catch that trips up a lot of people.
When you first enroll in Medicare at 65, you get a one-time window to buy Medigap without answering health questions.
Miss it, and an insurer can deny you or charge more because of a pre-existing condition.
A few states protect you later, but most don't.
That window is why financial advisers say the cheapest-looking option isn't always the smartest one.
Medigap does not, so you'd buy a separate drug plan.
Either way, check whether your specific medications sit on the formulary — the list of covered drugs — and what they'll cost you at the pharmacy counter.
Then there's the paperwork and the friction.
Advantage plans can require prior authorization for certain tests and procedures, and denials do happen.
If you hate fighting with insurers, that's worth weighing.
Medigap is quieter: you show your card, Medicare pays its share, and the supplement covers the rest.
There's no universal answer, and anyone who tells you otherwise is selling something.
A healthy 65-year-old who travels little might do fine with Advantage and bank the savings.
Someone with chronic conditions, a history of specialists, or a preference for predictable costs may sleep better with Medigap.
The real mistake is choosing once and never looking again.
Advantage plans change their networks and formularies every year, and your health can change too.
Read the Annual Notice of Change that arrives each fall — it's dull, but it's where the surprises hide.
Our take: treat this like a mortgage, not a magazine subscription.
Run your actual doctors, your actual prescriptions, and a worst-case hospital year through both options before you decide.
Final Thoughts
The plan that saves you $1,200 in premiums can cost you far more the first time you get sick.