Mass General Brigham Health Plan took Dana-Farber Cancer Institute out of its Medicare Advantage network on Oct. 1, and members in treatment there can keep going in network for 90 days after that date or through the end of their treatment plans. Medicare’s fall enrollment window closes Dec. 7, and any plan change made by then starts Jan. 1, 2027.
Counting 90 days from Oct. 1 lands at the end of December, which is only a few weeks after the enrollment deadline. For a patient on a defined course of treatment, the plan’s wording points to the end of that course. For a patient on open-ended maintenance therapy, the 90-day count is the safer assumption.
The people caught in this are Mass General Brigham Health Plan Medicare Advantage members who are seeing a Dana-Farber oncologist now, and members who are due for scans, infusions or radiation in the coming weeks. Each needs two answers before Dec. 7: when the continuity period ends for that member’s own treatment, and which 2027 plans, if any, keep Dana-Farber in network.
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Two clocks, and only one of them applies
The 90-day figure comes from Mass General Brigham Health Plan, as quoted by 24/7 Wall St.: 90 days after Oct. 1, “or through the end of their treatment plans.” Those are separate clocks, and which one governs depends on how the treatment is written up.
A patient finishing six rounds of chemotherapy has a clear end date. A patient on a daily pill, a monthly injection or surveillance scans has no natural end date, so the 90 days is the limit to plan around. The date should come from the plan in writing, not from a phone call.
Treatment that runs past the continuity period
Continuity of care is a bridge, not a destination. A member whose treatment is still going when the bridge ends has three paths, as the 24/7 Wall St. report lays them out: switch to a different Medicare Advantage plan that includes Dana-Farber for 2027, return to Original Medicare, or stay put and let the plan renew with Dana-Farber out of network.
The report calls the last choice “the trap.” Plans renew automatically unless a member acts, and a Medicare Advantage member who does nothing by Dec. 7 carries the network exit into 2027.
Can a cancer patient leave for a Medigap policy without medical questions?
That is the least certain part. Medicare.gov lists the situations in which a person who leaves Medicare Advantage has a guaranteed right to buy a Medigap policy, with an application window that runs from 60 days before the Advantage coverage ends to 63 days after. Outside those situations, the page says, there is no federal guarantee that an insurer will sell the policy.
The 24/7 Wall St. report says a network change does not automatically create that right. It would take a federal determination that the change is significant, or an exceptional-circumstances enrollment period, and the report found no confirmation that either exists here. In Iowa, by contrast, where insurers canceled plans outright, the state’s Insurance Division tells members they can move to Original Medicare and buy Medigap without medical underwriting. A network exit is a different event, and Massachusetts members should not assume the same rule.
What a Massachusetts supplement looks like
Massachusetts does not sell the Plan G that dominates the rest of the country. Its standardized supplements are called Core, Supplement 1A for people who became eligible for Medicare in 2020 or later, and Supplement 1 for those eligible earlier, according to the report. A patient comparing Original Medicare with a supplement needs those names, not the national letters, when calling insurers.
Original Medicare plus a supplement and a standalone Part D drug plan is a different structure from an Advantage plan, with its own monthly premiums. The cost of that trade is worth pricing out before Dec. 7, not after.
Questions to put to the plan and to Medicare
The report advises asking Mass General Brigham Health Plan how long continuity of care lasts for the specific treatment, and getting the end date in writing. It also advises calling 1-800-MEDICARE to ask whether any special enrollment period or guaranteed-issue right has been granted for this termination.
For anyone comparing other Advantage plans, the confirmation has to cover both Dana-Farber and the individual oncologist, for Jan. 1, 2027, with a reference number for the call. In the report’s words, “a 2026 network is not a promise about 2027.” Medicare’s free Plan Finder shows which 2027 plans list a given doctor.
Still in treatment when the 90 days run out?
Dec. 7 is the date to decide, and the end of December is when the plan’s bridge may close.
A Dana-Farber patient who lets the plan renew unchanged can end up paying out-of-network rates in the middle of a cancer course, with the continuity period already spent. A switch made in a rush, without checking the oncologist’s network status for 2027, can repeat the same problem under a new plan name.
The Medicare Money Bundle holds all 8 Medicare guides in one download, with large print. It includes Open Enrollment in an Afternoon: Plan Finder in one sitting, and a keep-or-switch answer, and Medigap vs. Medicare Advantage: Medigap rights, state rules, and both paths priced.
This article was produced with AI assistance and edited for accuracy against the sources linked above.
David M. Keller is a finance writer based in Columbus, Ohio, covering personal finance and consumer-focused economic topics. He earned his degree in journalism from Ohio University and began his career reporting on local business and economic trends for a regional media outlet. Since then, he has contributed to a variety of online publications, focusing on clear, practical coverage of topics such as cost of living, debt, and everyday financial decision-making.
