Your Medigap Plan F renewal notice landed, the number was bigger than last year, and the year before that was bigger too. You are not imagining the pattern, and the structure behind it is working against you in ways that compound with time.
Plan F once attracted a steady stream of 65-year-olds who wanted the most comprehensive Medicare supplement available on the market. That pipeline effectively shut down on January 1, 2020, when the Medicare Access and CHIP Reauthorization Act (MACRA) barred anyone newly eligible from purchasing the plan.
The law did not cancel existing policies, nor did it make Plan F illegal for pre-2020 enrollees who want to keep renewing it. What it did was set a demographic clock ticking inside every Plan F risk pool in the country, one that rewards leaving early.
Plan F enrollment dropped by 400,000 in a single year
Plan F enrollment stood at nearly 4.9 million in 2023, KFF reported in its analysis of National Association of Insurance Commissioners (NAIC) data. By the end of 2024, that figure had dropped to approximately 4.5 million, Mark Farrah Associates found in a separate review of the same dataset filed by 176 carriers.
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The decline reflects a predictable cycle that plays out when an insurance pool loses its supply of younger, healthier entrants. Without new 65-year-olds diluting the risk, average member age rises, per-member claims grow, and carriers file for larger premium increases.
Healthier members who can still pass medical underwriting shop around or switch to Plan G, concentrating sicker and older enrollees further. That remaining group absorbs a larger share of claims costs, and the next renewal reflects it, the KFF analysis of the same NAIC dataset confirmed.
Medical underwriting keeps older Plan F holders locked in
Plan G covers everything Plan F does except the annual Part B deductible, which is $283 in 2026, the Centers for Medicare and Medicaid Services (CMS) confirmed. Spread across 12 months, that gap works out to roughly $23.58, so any Plan F premium more than $24 above a comparable Plan G quote costs the holder more.
The math is straightforward, but getting through the door is not, because Medigap carriers in 46 states, U.S. territories, and Washington, D.C., can medically underwrite applications outside the initial six-month open enrollment window. Older enrollees with chronic conditions or prior surgical procedures may not qualify for Plan G at all, the Center for American Progress noted in a March 2026 report on the broader Medigap enrollment problem.
Only four states offer broader guaranteed-issue protections that let beneficiaries move between Medigap plans without a health screening. Connecticut, Massachusetts, Maine, and New York each require insurers to offer at least one policy on guaranteed-issue terms during an annual window, the report found.
“The Medigap trap exists because traditional Medicare and Medicare Advantage have never competed on a level playing field,” said Neda Ashtari, then-associate director of Health Policy at the Center for American Progress and co-author of the report. “Until we create real parity between the two—in financial protections, plan disclosures, and the rules governing enrollment—we’re not offering beneficiaries a choice. We’re engineering an outcome.”
That structural imbalance weighs heaviest on the people who stayed longest, because each birthday narrows the medical underwriting threshold further. The beneficiaries with the strongest financial reason to switch are precisely the ones an insurer is most likely to decline.
Rising Part B premiums compound the squeeze on Plan F holders
The standard Part B premium climbed to $202.90 per month in 2026 from $185.00 in 2025, a fixed cost that comes off every Social Security check. Medigap premiums stack on top of that, and Plan F holders absorb both increases without the offsetting benefit of a refreshed risk pool.
The standard Part B premium was $144.60 in 2020. Joanne Giardini-Russell, owner of the insurance agency Giardini Medicare in Michigan, pointed to the cumulative weight of those stacked increases.
“Now you go to $202.90, so that’s a pretty healthy clip,” she told NerdWallet in a recent Medicare enrollment guide.
Plan G, by contrast, continues to attract new 65-year-old enrollees whose younger demographics help stabilize the pool’s average claims cost. Plan G enrollment grew to more than 5.7 million members in 2024 from 5.3 million in 2023, the Mark Farrah Associates data showed.
Key data points for Plan F holders to track
Plan F vs. Plan G comparison:
- Plan F enrollment: approximately 4.5 million in 2024, down from 4.9 million in 2023, Mark Farrah Associates and KFF reported.
- Plan G enrollment: approximately 5.7 million in 2024, up from 5.3 million in 2023, the same analysis found.
- Part B deductible for 2026: $283 annually ($23.58 per month), CMS confirmed.
- Standard Part B monthly premium for 2026: $202.90, up from $185.00 in 2025, CMS reported.
- Jurisdictions with annual guaranteed-issue Medigap windows: Connecticut, Massachusetts, Maine, and New York, the Center for American Progress confirmed.
Medigap has no annual federal enrollment season, so the moment that matters most is whenever your carrier’s next rate notice arrives. Underwriting standards tighten with age, making this one of the rare Medicare decisions where acting sooner carries more weight than deciding perfectly.
