Dana-Farber Is Leaving a Medicare Advantage Network Oct. 1. Cancer Patients Face a Dec. 7 Decision About Their 2027 Care

“Collateral damage” is how one Massachusetts cancer patient described learning that her Medicare Advantage plan would stop covering Dana-Farber Cancer Institute as in-network care. On Oct. 1, 2026, Massachusetts insurer Mass General Brigham Health Plan is removing Dana-Farber from its Medicare Advantage network. For someone in the middle of chemotherapy, that reads like a countdown to losing an oncology team.

It isn’t, quite. But the date that actually decides next year is one most people won’t circle.

What Happens After Oct. 1

MGB says impacted members may continue receiving Dana-Farber care at in-network coverage for 90 days after Oct. 1, or through the end of their treatment plans. Those are two different clocks, and which one applies depends on your treatment. A patient finishing a defined course of therapy may be covered to the end of it. Someone on open-ended maintenance may be looking at the shorter window. This is the first call to make, and the answer is specific to you rather than to the announcement.

What it isn’t is a cliff on Dec. 31 that applies uniformly to everyone. Medicare’s Annual Enrollment Period runs Oct. 15 through Dec. 7, and it’s the window for arranging coverage that takes effect cleanly on Jan. 1. Advantage members do get a second chance. The Medicare Advantage Open Enrollment Period runs Jan. 1 through March 31 and allows one change. But an adjustment made then starts the following month, which means a gap for someone whose continuity period has run out. Dec. 7 is what buys a seamless transition.

Three paths exist, and doing nothing is one of them:

• Move to a different Medicare Advantage plan that has Dana-Farber in network for 2027.
• Return to Original Medicare, then add a stand-alone Part D plan and a Medicare Supplement policy.
• Let the current plan auto-renew, with Dana-Farber outside the network.

Auto-renewal is the trap, because it requires no decision and produces the worst version of one.

More Complicated Than It Looks

Two things make the return-to-Original-Medicare path harder than it sounds, and both get oversimplified. First, Massachusetts doesn’t sell the lettered plans you read about nationally. There’s no Plan G there. The state’s standardized products are Core, Supplement 1A for people newly eligible since 2020, and Supplement 1 for those eligible earlier. Shop for the wrong name and you’ll get nowhere.

Second, and more important: a hospital leaving a network does not automatically give you the right to buy a supplement without medical underwriting. That right can arise if CMS declares the network change significant, or grants an exceptional-circumstances special enrollment period to an individual. I found no confirmation that CMS has made either determination here.

So don’t assume it, and don’t take a sales representative’s word for it. Call 1-800-MEDICARE and ask directly whether a special enrollment period or guaranteed-issue right has been granted in connection with this termination. For a patient in active treatment, underwriting is the difference between a policy and a decline.

What Original Medicare Costs Right Now

For 2026, the standard Part B premium is $202.90 and the annual deductible is $283. Hospital coverage carries a $1,736 inpatient deductible per benefit period, $434 daily coinsurance for days 61 through 90, and $217 a day for skilled nursing days 21 through 100. CMS releases 2027 figures in November. Social Security’s 2027 raise is tracking in the mid-3% range, with the official number due in October.

A Massachusetts supplement sitting on top of Original Medicare is what turns that cost-sharing into something predictable. For a year of infusions, imaging, hospital stays and specialist visits, predictability is the entire point. What it costs depends on which product, your age and where you live, so get quotes rather than estimates. IRMAA surcharges and Part D gaps can add more on top, and we mapped those in a free guide to Medicare’s hidden bills.

Moves to Make Sooner Than Later 

• Ask MGB how long your continuity period actually runs. Ninety days after Oct. 1, or through the end of your treatment plan? Get it in writing, with the date.
• Call 1-800-MEDICARE to learn whether this termination carries a special enrollment period or guaranteed-issue right. That single answer determines whether Original Medicare plus a supplement is realistically available to you.
• If you’re comparing Advantage plans, confirm 2027 network status in writing. Name Dana-Farber and name your oncologist, and ask whether both are in network on Jan. 1, 2027. Get a reference number. A 2026 network is not a promise about 2027.

The plan change was made for reasons that have nothing to do with any individual patient. The response has to be individual anyway, and the window for making it closes in December.