If your doctor leaves your Medicare Advantage plan’s network, the plan has to tell you — at least 45 calendar days ahead for a primary care or behavioral health provider, and at least 30 for other specialists — and to keep getting covered services you generally have to choose someone else in the network (42 CFR 422.111(e)).
What you usually cannot do is walk away from the plan on the spot. Whether you get a way out depends on two things: what month it is, and whether Medicare treats the change as significant rather than as one doctor moving on.
Your plan can change its network any time. So can your doctor.
Medicare’s own consumer fact sheet says both halves of this out loud. Your Medicare Advantage plan “can add or remove providers from its network at any time during the year.” And separately: “Your provider can choose to leave your plan’s network at any time” (CMS Product No. 11941, May 2026).
That is the structural bargain of a network plan: lower cost-sharing, often extra benefits, because the plan negotiated rates with a defined set of doctors and hospitals. Contracts get renegotiated, and sometimes they fail. In a market like Tampa Bay, where a handful of large systems account for much of the specialty care from St. Petersburg down to Sarasota, one contract dispute can move a lot of people’s cardiologists at once.
None of that makes Medicare Advantage the wrong choice. It makes the network the thing you check first — before you enroll, and again every fall.
What the notice actually gets you
| Who is leaving | What the plan must do | How far ahead |
|---|---|---|
| Primary care or behavioral health provider | Written notice and one attempt to reach you by phone | At least 45 calendar days |
| Any other specialty | Written notice | At least 30 calendar days |
Those are the rules in 42 CFR 422.111(e), which also defines who counts as “you”: for a primary care or behavioral health termination, everyone assigned to that provider and everyone who has been their patient in the past three years; for other specialties, anyone assigned to, currently receiving care from, or seen within the past three months by the provider being terminated.
The notice is not permission to keep seeing the doctor. It is time to plan. Use it.
One thing worth knowing: your plan “must protect you from interruptions in medical care and make sure you have access to medically necessary covered benefits,” and if you want to continue ongoing treatment with your current provider, the plan has to tell you how to request that. There is no automatic grace period that carries you through — you have to ask, in writing, and the plan decides. If you believe a network change will interrupt your care and put your health at risk, Medicare’s instruction is to call 1-800-MEDICARE (1-800-633-4227).
Can you change plans? Look at the calendar first.
Three doors, and only one of them is always open.
January 1 – March 31. Anyone enrolled in a Medicare Advantage plan can make one change: to a different Medicare Advantage plan, or back to Original Medicare, with a coordinating Part D election (42 CFR 422.62(a)(3)). If your doctor exits in February, this is your door.
October 15 – December 7. Medicare Open Enrollment, for coverage starting January 1. Medicare’s fact sheet tells you exactly what to do with it: check whether your providers are in the plans you’re considering before you pick one.
A Special Enrollment Period, if the change was big enough. Federal rules create an SEP for enrollees “affected by a significant change in plan provider network,” letting you move to another Medicare Advantage plan or to Original Medicare. It can be used once per significant change, and it runs from the month you’re notified through two more calendar months. The catch is in the same paragraph: the plan issues that notice when instructed by CMS. One retiring internist will not trigger it. A hospital system or a large multi-specialty group leaving might.
If your doctor left in June and no SEP notice arrived, the honest answer is that the next dependable door is October 15. Our enrollment periods guide lays out how the windows stack up against each other.
The part most people miss: a network change can open a Medigap door
Here is the piece that rarely makes it into the phone call with the plan. Medicare’s official Medigap guide lists four situations that give you a guaranteed issue right — a right to buy certain Medicare Supplement policies where the insurer must sell to you, must cover your pre-existing conditions, and can’t charge you more because of your health. One of the four is: “Your plan’s network has a significant change” (CMS Product No. 02110, 2026).
Two conditions attach to it, and both matter:
- You only have this right if you switch to Original Medicare, not if you move to another Medicare Advantage plan.
- The clock is short. You can apply as early as 60 days before your Medicare Advantage coverage ends, and no later than 63 days after it ends. The Medigap policy can’t start until the Advantage coverage stops.
What you can buy under that right is Medigap Plan A, B, C, D, F, or G sold in your state — with Plans C and F off the table for anyone new to Medicare on or after January 1, 2020, who has the right to buy Plan D or G instead. Our Plan G vs Plan N comparison walks the cost-sharing difference, and the annual Medicare cost estimator shows what a year on Original Medicare plus a supplement and a drug plan actually runs.
This is not a case for Medigap over Medicare Advantage. A supplement carries a monthly premium a network plan may not, and it doesn’t include drug coverage or the extras some Advantage plans offer. The point is narrower: outside a guaranteed issue right or your one-time Medigap Open Enrollment Period, an insurer is allowed to deny you a policy on medical underwriting (Medicare.gov). That asymmetry is why a network notice is worth reading rather than filing — more on it in what happens if you miss your Medigap window.
HMO or PPO changes the answer
Plan type decides how much room you have while you sort this out.
- HMO — you generally must use network providers for non-emergency care. Emergency care, out-of-area urgent care and out-of-area dialysis are covered either way. An HMO with a point-of-service option may allow certain services out of network, usually at a higher cost.
- PPO — you can go to providers outside the network, but you’ll usually pay more.
- PFFS — depends on whether the plan has a network and whether the provider accepts the plan’s terms. Not all will.
For Florida retirees who spend part of the year elsewhere, that distinction does double duty: it governs both what happens when a local doctor exits and what happens when you need care three states away.
What to do first
- Read the notice for the effective date. That date, not the postmark, starts your clock.
- Call the provider’s office. Ask whether the exit is final and which plans they’ll be in next year.
- Call the plan and ask two things — whether you qualify for continued in-network cost-sharing to finish current treatment, and whether this termination carries an SEP notice.
- Check the directory for a replacement, then confirm by phone with the new office. Directories go stale.
- Mark October 15. Even if you land somewhere fine, verify your providers against next year’s networks before you renew.
Networks are a design feature, not a defect — and a supplement’s freedom of provider is paid for with premium. Which trade you want depends on your doctors, your prescriptions, your travel and your budget.
If a notice has landed and you’re not sure which of these doors is open to you, book a time and we’ll read it together. Virginia Barausky is based in Tampa and works with families across Florida. We do not offer every plan available in your area, and this is education rather than a recommendation about your situation — but figuring out which window you’re standing in is a good half-hour’s work.