Most brokers who sell Medicare Supplement know Plan F is closed. Fewer have done the annual math on every Plan F client in their book to find out whether staying is still the rational decision. In most markets, it is not. The premium gap between Plan F and Plan G has widened consistently since 2020, and in many counties that gap now exceeds $500 per year for a 70-year-old client, against a coverage difference of exactly $257, the 2026 Part B deductible.
Key Takeaways
- Congress closed Medigap Plan F and Plan C to new Medicare beneficiaries effective January 1, 2020, under Section 106 of MACRA. Only clients whose Medicare Part A effective date is on or before December 31, 2019, can still enroll.
- Plan F covers every gap in Original Medicare, including the Part B deductible ($257 in 2026). Plan G covers every gap except the Part B deductible. The annual net-cost difference between them is exactly the Part B deductible amount.
- Because no new healthy enrollees are entering the Plan F risk pool, average Plan F premiums have climbed faster than Plan G premiums since 2020. In most markets, the annual Plan F premium now exceeds the Plan G premium by more than $257, making Plan G the cheaper total-cost option.
- Switching from Plan F to Plan G in most states requires medical underwriting. Only six states plus the District of Columbia have rules that allow switching between Medigap plans without answering health questions after the initial open enrollment window.
- For clients who are still insurable, the break-even math is simple: if the Plan F annual premium minus the Plan G annual premium exceeds $257, the client saves money by switching. Run this calculation annually because the gap widens each year as Plan F adverse selection accelerates.
What Congress actually did in 2015 and why it matters now
The Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) included a provision, Section 106, that banned the sale of Medigap plans covering the Medicare Part B deductible to newly eligible Medicare beneficiaries starting January 1, 2020. The policy rationale: first-dollar coverage removes the cost signal that deductibles create, leading to higher utilization and higher Medicare spending overall. Congress decided to phase out those plans rather than ban existing coverage outright.
The result is a closed risk pool with no exit mechanism. Existing Plan F holders can keep their coverage and renew it indefinitely. They cannot, however, add healthy new members to balance the actuarial ledger. Every year that passes, the Plan F pool becomes a year older, a year sicker, and a year more expensive to insure.
The coverage difference is exactly one line item
Plan G covers everything Plan F covers except the Part B deductible. That is the complete list of differences. Both plans cover the Part A deductible ($1,676 in 2026), Part A coinsurance for hospital stays beyond 60 days, Part B coinsurance (the standard 20 percent of Medicare-approved amounts), Part B excess charges (the 15 percent above Medicare-approved that non-assignment providers can charge), skilled nursing facility coinsurance, hospice care coinsurance, and emergency care during foreign travel up to plan limits.
The only thing Plan F pays that Plan G does not is the Part B deductible, which is $257 in 2026. A client on Plan F who switches to Plan G will pay $257 out of pocket once per year, at their first Part B service, and then pay nothing for the rest of the year on Part B costs the same as they did on Plan F.
The break-even calculation brokers should run annually
The math is not complicated. Pull the current Plan F and Plan G rates for the client's specific age, gender, and county from any carrier that writes both. Subtract the annual Plan G premium from the annual Plan F premium. If the difference exceeds $257, the client saves money by switching to Plan G, assuming they can pass underwriting.
Example: a 72-year-old nonsmoking woman in a suburban Texas county whose Plan F premium is $315 per month and whose Plan G premium from the same carrier is $240 per month. Annual Plan F cost: $3,780. Annual Plan G cost: $2,880 plus the $257 Part B deductible once per year, total $3,137. Annual savings from switching: $643. The Part B deductible paid annually for two years does not fully offset one year of the premium difference.
Illustrative example. Actual premiums vary by carrier, age, county, gender, and tobacco use. Pull current carrier rates before advising any client.
Quotit and similar Medicare quoting platforms surface Plan F alongside Plan G for grandfathered-eligible clients, but none of them run the total-cost comparison automatically. The break-even worksheet is a manual step, and it is the broker conversation that keeps clients from overpaying for coverage they cannot meaningfully use.
The adverse selection dynamic: why the math gets worse each year
Adverse selection describes what happens when a risk pool loses its healthier, lower-cost members while retaining its sicker, higher-cost ones. Plan F has a structural adverse selection problem because the clients who can pass underwriting and switch to Plan G do switch, and those who cannot stay on Plan F regardless of cost.
Actuaries who have modeled the Plan F pool expect premiums to continue rising at a rate above general medical inflation for the foreseeable future. Some carriers have already stopped writing Plan F in certain states because the risk is no longer actuarially manageable at competitive rates. A broker who waits another five years to have this conversation with a 70-year-old client may find that client uninsurable by then, or priced into a carrier with dwindling Plan F enrollment and accelerating premiums.
States where switching does not require underwriting
A minority of states have enacted rules that allow policyholders to switch between Medigap plans without answering health questions after the initial open enrollment window. For clients in these states, the switch from Plan F to Plan G is straightforward as long as the new plan offers equivalent or lesser coverage.
| State | Rule type | Switching timing |
|---|---|---|
| New York | Continuous open enrollment | Any time, any reason, any plan |
| Connecticut | Continuous open enrollment | Any time, any reason, any plan |
| Massachusetts | Continuous open enrollment | Any time, any reason, any plan |
| Maine | Continuous open enrollment | Any time, any reason, any plan |
| Washington | Continuous open enrollment | Any time, any reason, any plan |
| California | Birthday rule | 30-day window starting on birthday each year |
| Oregon | Birthday rule | 30-day window starting on birthday each year |
State rules change. Confirm current law with the state insurance department or a licensed attorney before advising clients on switching rights.
In all other states, switching from Plan F to Plan G is a new application subject to the carrier's underwriting guidelines. Declines are possible. Rated premiums are possible. Brokers should run the health qualification conversation before raising the client's expectations about switching.
When staying on Plan F is the right answer
Not every Plan F client should switch. Three situations favor staying:
First, clients who cannot pass underwriting in states without guaranteed switching rights. If a client has diabetes, a recent cardiac event, active cancer treatment, or other conditions that trigger decline or rating, they are effectively locked into Plan F. The premium premium is the cost of insurability they cannot replace.
Second, clients whose Plan F premium is close enough to Plan G that the total-cost difference is negligible. In some markets and for some ages, the spread is still under $200 annually. The underwriting hassle and risk of change may not be worth it.
Third, clients who are in the middle of significant health events and expect high Part B utilization in the coming year. The $257 Part B deductible exposure on Plan G, while small, is real during an active treatment period.
The broker workflow: annual Plan F review
The Plan F review belongs in the annual renewal workflow for every Medicare client who holds the plan. The steps:
Pull the current Plan F and Plan G rates from the same carrier the client is on. Calculate the annual premium difference. If it exceeds $300 (a conservative buffer above the $257 deductible), flag the client for a switching conversation. Ask the health qualification questions informally before ordering the application. For clients in states with birthday rules, note the next window on the calendar and initiate the conversation 30 to 45 days in advance.
The clients most at risk of overpaying are the ones who enrolled in Plan F in 2019 and have been auto-renewing without a review. They are now several years into a premium trajectory that has likely outpaced inflation, and the spread to Plan G has widened each year they stayed.
Medigap Plan F: broker FAQ
Common questions from brokers advising clients who enrolled in Plan F before 2020.
Can a client who turned 65 after January 1, 2020 still buy Medigap Plan F?
No. Plan F and Plan C are closed to any beneficiary whose Medicare Part A coverage became effective on or after January 1, 2020. The law (MACRA Section 106) uses the Part A effective date, not the birthdate. A client who turned 65 in December 2019 but whose Part A did not start until January 2020 cannot enroll in Plan F. Clients who were eligible for Medicare due to disability before 2020 may also qualify, depending on when their Part A coverage began.
Why are Plan F premiums rising faster than Plan G?
Plan F is a closed risk pool. No new, typically healthier, enrollees are entering. The remaining pool is aging, and as older clients generate more claims, the insurer must raise premiums to cover costs. This dynamic, sometimes called adverse selection or a closed-block problem, compounds each year. Clients who remain healthy migrate to Plan G (or drop Medigap entirely), leaving a sicker, higher-cost population in Plan F. Actuaries expect the trajectory to continue indefinitely because no regulatory mechanism can reopen the pool.
In what states can a client switch from Plan F to Plan G without medical underwriting?
Six states and the District of Columbia have continuous open enrollment or guaranteed-issue rules that allow policyholders to switch between Medigap plans at any time without health questions: Connecticut, Maine, Massachusetts, New York, and Washington have continuous open enrollment. California and Oregon have birthday rules that allow switching during a brief annual window (30 to 60 days after the insured's birthday) to a plan with equal or lesser benefits. Minnesota and Wisconsin use their own standardized plan frameworks with different rules. In all other states, switching from Plan F to Plan G after the initial enrollment window requires answering health questions, and insurers can decline coverage or add riders.
What happens if a client on Plan F develops a health condition and now wants to switch to Plan G?
If the client is in a state without continuous open enrollment or a birthday rule, the switch requires full medical underwriting. Conditions like diabetes, heart disease, COPD, cancer history, or recent hospitalizations can result in denial or rated premiums. In that case, the client is effectively locked into Plan F. The cost of staying on Plan F is the premium difference above Plan G premiums each year, which in many markets now exceeds $500 to $800 annually. For a client in poor health, that annual cost may still be lower than the out-of-pocket risk of moving to a plan with more exposure.
Does Plan F still pay Part B excess charges in 2026?
Yes. Plan F covers Part B excess charges, which are the amounts a provider who does not accept Medicare assignment can charge above the Medicare-approved rate, capped at 15 percent above that amount. Plan G also covers excess charges, so switching from Plan F to Plan G does not eliminate excess charge protection. The only meaningful coverage difference between the two plans is the Part B deductible, which is $257 in 2026. Plan N, by contrast, does not cover excess charges, making it the plan where the excess charge exposure actually changes the coverage analysis.
