At 69, She Tried to Leave Medicare Advantage. Her Cancer Had Been Gone Four Years. One Medigap Insurer Required Five
Four years in remission sounds like a clean slate, but one Medigap insurer's underwriting clock told a different story, and leaving Medicare Advantage before getting that answer could have cost her everything Original Medicare does not cover.
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A 69-year-old woman finished cancer treatment four years ago and is in remission. She spent those four years inside a Medicare Advantage plan, battling prior authorization requests and network restrictions. Now she plans to use Annual Enrollment, which runs October 15 through December 7, to switch to Original Medicare and add Medigap Plan G.
In this example, her first Medigap application asks whether she has been diagnosed with or treated for cancer within the past five years.
She is not alone. People leaving Advantage with a serious diagnosis face the same risk unless federal or state protections give them the right to buy Medigap without medical underwriting. A healthier applicant may have a far easier path to approval.
Medicare Takes Her Back, but Medigap Gets to Decide
Original Medicare will re-enroll her without asking a single question about cancer. Medigap is sold by private insurers, and in most states they can ask whatever health questions state law permits. That supplement is what plugs Original Medicare’s open-ended cost sharing.
Annual Enrollment gives her the right to leave Advantage. Her right to buy Medigap without health questions comes from a separate, narrower set of rules. Her federal guarantee was a one-time six-month Medigap Open Enrollment Period that began when she first enrolled in Part B. That window closed years ago. Outside it, insurers in most states can review her medical history and decline coverage.
Federal trial rights generally protect people who joined Advantage when first eligible at 65, or who dropped Medigap to try Advantage for the first time, then leave within 12 months. Four years in, she is well past that trial window.
The five-year lookback is one carrier’s rule. Medicare does not set it. A different insurer might look back only two years, ask only about active treatment, accept certain cancer histories, or charge a higher premium for the added risk where state law permits.
The exact wording of the question also determines when the clock starts. A carrier may count from her last treatment, not her diagnosis. If she still takes a daily cancer-prevention drug or sees her oncologist annually, she should ask how the insurer treats those details. A routine follow-up visit does not necessarily restart the clock.
It is also worth noting that new federal rules effective January 1, 2026 now require Medicare Advantage plans to decide standard prior authorization requests within seven calendar days and urgent requests within 72 hours, and to provide a specific documented reason for any denial. Those timelines apply going forward; they do not change the Medigap underwriting clock.
Leaving Advantage First Leaves Her With No Cap
Original Medicare has no annual out-of-pocket maximum. If she drops Advantage before her Medigap coverage is approved for January, she begins the year with Original Medicare and nothing to cover the gaps. On top of her monthly Part B premium, she would owe these costs herself:
| Cost-Sharing Item | How Often It Applies | 2026 Amount Per Person |
|---|---|---|
| Part B deductible | Once per year | $283 |
| Part B coinsurance | Every covered outpatient service | 20% of the approved amount, with no cap |
| Part A hospital deductible | Each benefit period | $1,736 |
| Hospital days 61 to 90 | Per day, each benefit period | $434 |
| Skilled nursing days 21 to 100 | Per day, each benefit period | $217 |
The 20% Part B coinsurance is the most dangerous exposure. If her cancer returns, chemotherapy administered in a doctor’s office generally leaves her paying 20% of the Medicare-approved amount after the Part B deductible, with no annual ceiling. Advantage’s in-network cap protected her from that exposure. Standard Plan G would cover that coinsurance. Original Medicare alone does neither.
She also loses the drug coverage built into her Advantage plan. A standalone Part D plan must start on the same day her Advantage coverage ends. Premium surcharges, coverage gaps, and other traps like this are the subject of our free Medicare guide.
Get Approved Before You Leave Advantage
- Compare health questions before filing. Get current Medigap applications from at least three carriers. Check each question’s exact wording against your dates: diagnosis, last treatment, last medicine, last follow-up visit. Apply first to the carrier whose lookback your records clear.
- Apply with a future effective date and wait for written approval. Request Medigap coverage starting January 1. Once written approval arrives, complete your Advantage disenrollment and enroll in a separate Part D plan before December 7. If approval never comes, your current plan stays active.
- Call your state insurance department or State Health Insurance Assistance Program (SHIP). Some states give broader Medigap switching or guaranteed-issue rights that override carrier health questions. As of 2026, roughly 16 states offer birthday rules or other annual switching protections that go beyond what federal law requires, and states including Delaware, Maryland, Minnesota, and Rhode Island added or expanded those protections in 2025 and 2026. If your state is among them, the five-year question may not apply.
If every carrier turns her down, the right move is to stay in Advantage and use Annual Enrollment to find a plan whose network includes her oncologist. Its in-network out-of-pocket cap offers far more protection than Original Medicare with no supplement.
Her oncologist’s remission clock had reached four years. The insurer’s underwriting clock required five, and leaving Advantage would have left her exposed to the difference.
Editor’s note: This update adds context on the 2026 CMS prior authorization rules (CMS-0057-F) requiring Medicare Advantage plans to issue decisions within seven calendar days for standard requests, and notes the expanded state-level Medigap guaranteed issue protections enacted by Delaware, Maryland, Minnesota, Rhode Island, and others in 2025 and 2026.
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Gerelyn Terzo is the author of dividend investing handbook "Dividend Investing Strategies: How to Have Your Cake & Eat It Too." A veteran financial journalist, she covers agri-finance for outlets like Global AgInvesting and the broader stock market and personal finance for 24/7 Wall Street. She began at CNBC and later helped launch Fox Business in New York. Gerelyn currently resides in Woodland Park, Colorado and dabbles in nature photography as a hobby.
