Medicare
Advantage or Medigap: the Medicare decision that is hard to undo
Both routes are legitimate and both are chosen by sensible people. What almost nobody explains is that switching later is not symmetrical — one direction is guaranteed, the other may not be.
This is the biggest choice in Medicare, and there is no universally right answer. Both routes are legitimate, both are chosen by reasonable people, and which one fits depends on facts about your life rather than on which one is "better."
What deserves more attention than it usually gets is that the decision is not equally reversible in both directions.
The two structures, briefly
Original Medicare plus a Medigap policy. Medicare pays its share, and the Medigap policy covers much of what is left — deductibles, copays, coinsurance. You typically add a separate Part D plan for prescriptions. You can see any provider in the country who accepts Medicare, which is most of them, and you do not need referrals.
Medicare Advantage (Part C). A private insurer takes over your Part A and Part B coverage and usually bundles drug coverage in. Plans often include extras that Original Medicare does not cover at all. In exchange, you use the plan's provider network, and you pay copays and coinsurance as you use care, up to an annual out-of-pocket maximum.
Where the money actually sits
The honest comparison is not "which is cheaper." It is when you pay.
| Original Medicare + Medigap | Medicare Advantage | |
|---|---|---|
| Monthly cost | Higher — Part B plus a Medigap premium plus Part D | Often lower, sometimes little beyond the Part B premium |
| Cost when you need care | Low and predictable | Copays and coinsurance per service |
| Choice of doctors | Any provider accepting Medicare, nationwide | The plan's network |
| Referrals to specialists | Not required | Often required |
| Annual cap on your spending | Effectively handled by the supplement | A defined out-of-pocket maximum |
Advantage shifts cost from the monthly bill to the moment you use care. Medigap does the opposite: you pay more every month and far less when something happens.
That is why the same question — "which is cheaper?" — has opposite answers depending on the year you are having. In a healthy year, Advantage usually wins. In the year of a hospitalisation, a cancer diagnosis or a joint replacement, the supplement route tends to look very different.
The asymmetry that matters most
This next part I make sure every client hears before signing anything.
Going into Medicare Advantage is easy at any Annual Enrollment Period. Coming back to Original Medicare is also easy — but buying the Medigap policy that makes Original Medicare affordable may not be.
Your guaranteed right to buy any Medigap policy, at any insurer, regardless of your health, lasts six months from the first month you are 65 or older and enrolled in Part B. After that window, federal law stops guaranteeing it. Insurers may require medical underwriting and may decline you outright.
So the practical shape of the decision is this: choosing Medigap first keeps both doors open, because you can move to Advantage later. Choosing Advantage first may quietly close one of them, because your health five years from now decides whether you can go back.
How to actually decide
Three questions get you most of the way there.
- Who are your doctors, and are they in the network? Not "is there a good hospital nearby" — the specific names. If you have a specialist you trust and would not change, that fact alone narrows the choice.
- What do you take, and is it on the formulary? Drug lists are plan-specific and change annually. A plan that covers your medication cheaply this year may not next year.
- Do you travel or spend part of the year elsewhere? Networks are usually regional. Original Medicare is not.
Then compare on total exposure, not on premium. A plan costing $40 less a month is not cheaper if a single hospital stay costs you thousands more.
What I do with clients
I check your actual doctors against the actual networks, run your actual medication list against the formularies, and lay out what each route costs in a normal year and in a bad one. Then you choose — with the numbers in front of you rather than a brochure.
That comparison is free, and it takes about half an hour. See how Medicare coverage fits with the rest of what you have, or just get in touch and we will start with your doctors.
Frequently asked questions
Which is cheaper, Medicare Advantage or Medigap?
It depends on the year you have. Advantage usually costs less per month and more when you use care; Medigap costs more per month and far less when something serious happens. Compare total exposure over a year, not the premium.
Can I switch from Medicare Advantage back to Original Medicare?
You can return to Original Medicare during the Annual Enrollment Period or the Medicare Advantage Open Enrollment Period. The harder part is buying a Medigap policy afterwards — outside your guaranteed-issue window, insurers may require medical underwriting and can decline.
Do I need a separate drug plan with Medigap?
Usually yes. Medigap does not cover prescriptions, so most people add a standalone Part D plan. Many Medicare Advantage plans include drug coverage instead.
Can I keep my own doctors?
With Original Medicare plus Medigap you can see any provider in the country who accepts Medicare. With Medicare Advantage you are limited to the plan's network, which is why checking your specific doctors before enrolling matters.