A letter arrives in late summer. The hospital system a retiree has used for 20 years, the one that houses her cardiologist and her oncologist and her primary care doctor, will no longer accept her Medicare Advantage plan as of a date printed near the bottom of page two. She had made no changes on her end. Her plan stayed in place on paper. The contract between the two of them ended, and she found out by mail.
This scenario has become common enough that it is worth understanding before the next Annual Enrollment Period. If you are on Original Medicare with a Medigap policy, this article is largely not about you. If you are on a Medicare Advantage plan, or considering one at 65, the mechanic below is the one that will most likely bite.
Why Hospitals Are Walking Away Mid-Contract
Hospital systems and physician groups across the country have terminated or declined to renew Medicare Advantage contracts over the past two years, citing three recurring problems: prior-authorization friction, claim denials, and slow or low reimbursement from MA plans. In plain terms, hospitals say they treat the patient, then spend months arguing with the insurer over whether the care was necessary and how much of it will be paid.
The insurer side of the ledger explains the pressure. Elevance Health (NYSE:ELV | ELV Price Prediction), one of the largest managed care companies in the country, reported that elevated medical costs in government businesses contributed to an increased benefit expense ratio in its most recent quarter. When insurers face rising costs on MA members, they tighten authorization rules and push back harder on hospital bills. Hospitals absorb the delay, then decide the contract is not worth renewing.
The result lands in a patient’s mailbox.
What the Letter Actually Means
A mid-year network termination leaves your Medicare Advantage plan in place. Your plan continues, but the hospital or physician group inside it does not. Once the termination date passes, visits to that provider are treated as out-of-network. On most HMO-style MA plans, out-of-network care is not covered at all except in emergencies. On PPO-style plans, it is covered at a higher cost share, and out-of-network spending typically does not count toward the in-network out-of-pocket maximum.
The advertised in-network cap on your plan stops protecting you the moment your hospital leaves the network.
The Protections That Actually Apply
Federal continuity-of-care rules require Medicare Advantage plans to allow certain patients, typically those in active treatment for serious conditions, pregnancy, or end-stage illness, to continue seeing a departing provider at in-network cost sharing for a transitional period. The plan sets the exact terms, and the patient must request it. It is not automatic.
A Special Enrollment Period may open when a plan experiences a significant network change, which lets the member switch to another MA plan or return to Original Medicare outside the usual October-to-December window. CMS decides case by case whether an SEP applies, so the letter from the plan is the first place to check. If it grants an SEP, use it.
The Switch-Back Trap
Returning to Original Medicare sounds like the clean fix. It is not that simple after the first six months of Part B enrollment. Outside that federal Medigap open enrollment window, a Medigap insurer in most states can medically underwrite, charge more, or deny coverage entirely. A handful of states, including New York, Connecticut, Massachusetts, and Maine, offer broader guaranteed-issue rights. Everywhere else, a 72-year-old with a cardiac history who wants to leave her MA plan may find Medigap effectively closed to her.
This is the cost of the original MA decision that the $0 premium never advertised. Getting in is easy. Getting out clean is not. (For retirees mapping the broader landscape of surprise Medicare costs, the Medicare’s Hidden Bills report walks through the categories worth stress-testing before enrollment.)
What To Do Now
- Read every plan letter the month it arrives. Network termination notices are legally required, but they look like junk mail. The effective date on page two is the only date that matters.
- Re-verify your provider network every Annual Enrollment Period, which runs October 15 to December 7. Do not assume last year’s network carries forward. Call the hospital’s billing office directly and ask which MA contracts they will honor for the coming plan year, not just which they accept today.
- If you are still inside your six-month Medigap open enrollment window, price a Medigap Plan G or Plan N against your current MA plan before that window closes. The underwriting protection you have right now expires once, and never returns in most states.
With the 2026 Social Security COLA at 2.8%, most retirees have little slack in their monthly budget for an out-of-network hospital bill they did not plan for. The letter in the mailbox is the warning. The action window closes fast.
Contact [email protected] for any questions or corrections.
Top Gaining Stocks
Top Losing Stocks