The letter usually arrives without warning: effective next month, your physician group — or your hospital system — will no longer participate in your Medicare Advantage plan. You chose the plan partly because those providers were in it, and now, in the middle of the plan year, they are not. The question everyone asks first is whether this lets you switch plans. Sometimes it does. More often it does not, and the more useful question becomes what protections apply while you stay put. Here is how mid-year network changes work in 2026 and what options are realistically available.
Networks Can Change Any Month
Medicare Advantage networks are built on contracts between plans and providers, and those contracts can end at any point during the year — sometimes because the plan drops a provider, sometimes because a health system chooses to leave over payment disputes. Neither situation requires waiting for January.
Plans are required to make a good-faith effort to notify affected enrollees in advance when a provider they use leaves the network, generally at least 30 days ahead for the people known to be receiving care from that provider. In practice, notice quality varies, and some people learn at the front desk of an appointment they have already scheduled.
First step: verify it. Call the provider's billing office and ask directly whether they are still contracted with your specific plan — not just the insurer, since a system may participate in some of an insurer's plans and not others. Then call the plan and ask the same question, and request the answer in writing. Provider directories are not always current, which is exactly why the directory accuracy rules described below exist.
Continuity of Care: The Protection Most People Miss
CMS requires Medicare Advantage plans to offer continuity-of-care protections when a provider leaves the network mid-treatment. If you are in an active course of treatment — chemotherapy, post-surgical recovery, dialysis, management of a serious chronic condition — you may be able to keep seeing that provider at in-network cost sharing for a transition period, commonly up to about 90 days.
Two things to know:
- It is not automatic. You generally have to call the plan and request it, and the plan sets the specific terms
- Routine care usually does not qualify. Stable conditions, medication management, and general check-ups are typically expected to transition to another network provider
When you call, be specific: name the condition, the treatment in progress, the provider, and the expected duration. Ask for the approval in writing and for the exact end date of the transition period. If the plan denies the request, that denial can be appealed — see our guide to appealing a Medicare decision.
What It Costs If You Keep Going Out of Network
If continuity of care does not apply, the plan type determines your exposure:
- HMO plans generally do not cover out-of-network care at all, except for emergency care, urgently needed care, and out-of-area dialysis. Seeing the provider anyway typically means paying the full cost yourself
- PPO plans cover out-of-network care at higher cost sharing, and out-of-network spending counts toward a separate, higher combined out-of-pocket limit rather than the in-network maximum of no more than $9,250 in 2026
Our guides to Medicare Advantage networks and how HMO and PPO plans compare explain the cost structures in more detail.
When a Network Change May Open a Special Enrollment Period
A provider leaving the network does not automatically create a Special Enrollment Period. CMS may grant one when it determines the network change is significant — judged by the scope of the change and its effect on enrollees who are assigned to, currently receiving care from, or who received care within the past three months from the terminated provider or facility.
When CMS grants this SEP, it generally begins the month enrollees are notified and continues for two additional calendar months. The loss of a single primary care physician rarely meets the standard; the departure of a region's main hospital system or its only cancer center is a different situation.
How to find out whether it applies to you: read the termination letter carefully — if an SEP is available, the notice generally says so — and call 1-800-MEDICARE. Plan representatives do not always know, and the determination is CMS's to make.
A separate SEP available during 2026 applies to people who chose a Medicare Advantage plan based on provider directory information shown in the Medicare Plan Finder and then discovered the provider was not actually in network. CMS created it because provider directory data was added to Plan Finder recently and some entries proved inaccurate. In general terms, it applies to Medicare Advantage enrollments with 2026 effective dates, must be used within about three months of coverage starting, and is available only by calling 1-800-MEDICARE — not through a plan or agent. Beginning in 2026, plans must also submit directory data to CMS, attest to its accuracy at least annually, and update it when information changes.
CMS has additionally proposed broadening the network-change SEP for the 2027 contract year — including counting enrollees who were scheduled to receive care from a terminated provider, and clarifying that the SEP applies when a hospital or health system chooses to leave a network. Those changes are proposals, not current rules.
If No Special Enrollment Period Applies
Two regular windows remain:
- Medicare Advantage Open Enrollment Period (January 1 – March 31): if you are enrolled in a Medicare Advantage plan on January 1, you may make one change — to a different Advantage plan, or back to Original Medicare with the option to add a Part D plan
- Annual Enrollment Period (October 15 – December 7): open to everyone, with changes effective January 1. Our AEP guide covers what can be changed
One caution if you are considering a return to Original Medicare: buying a Medigap policy outside your initial open enrollment window may require medical underwriting in most states, and a carrier may decline coverage or charge more based on health history. Our guides to switching back to Original Medicare and guaranteed issue rights explain when underwriting may be waived.
A Practical Checklist
- Confirm the change in writing with both the provider's billing office and the plan
- Request continuity of care immediately if you are in active treatment, and get the approved end date in writing
- Ask 1-800-MEDICARE whether a Special Enrollment Period applies to your situation
- Identify replacement providers and verify by phone that they are accepting new patients under your specific plan
- Check whether referrals or prior authorizations need to be reissued — approvals tied to a departing provider often do not transfer
- Keep the termination letter. It is the documentation that supports an SEP request or an appeal
How to Get Help and Learn More
- Medicare.gov — Compare plans and check provider information at medicare.gov/plan-compare.
- 1-800-MEDICARE (1-800-633-4227) — The place to confirm whether an SEP applies. TTY users can call 1-877-486-2048.
- State Health Insurance Assistance Program (SHIP) — Free, unbiased counseling on network changes and your options. Find your local office at shiphelp.org.
Summary and Next Steps
- Medicare Advantage networks can change mid-year, and plans must make a good-faith effort to notify affected enrollees
- Continuity of care may let you keep an out-going provider at in-network cost sharing during active treatment, commonly up to about 90 days — but you must request it
- A provider departure does not automatically create a Special Enrollment Period; CMS grants one case by case when a network change is significant, running the month of notice plus two months
- A temporary 2026 SEP may apply if you enrolled based on inaccurate Plan Finder directory information — available only through 1-800-MEDICARE
- Otherwise, the MA Open Enrollment Period (January 1 – March 31) allows one change, and AEP (October 15 – December 7) is open to everyone
- Returning to Original Medicare may involve Medigap medical underwriting depending on your state and situation
Start with two phone calls — the provider's billing office and the plan — and ask for everything in writing. Those documents determine which of the options above are actually available to you.
