Quick answer: Medigap Plan G covers everything Plan F covers except the Medicare Part B annual deductible ($283 in 2026). If your Plan G premium would be lower than your Plan F premium by more than that deductible over a year, Plan G may cost you less in total. In California, the Birthday Rule lets existing Medigap policyholders move from Plan F to Plan G — with any insurer that offers it — with no health questions, during an annual window that begins on your birthday.
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If you have had Plan F for years, you have probably noticed two things: the premium keeps climbing, and people keep mentioning Plan G. This guide explains the actual difference between the two plans, how to do the arithmetic for your own situation, and the California-specific rule that makes the switch easier here than in most states.
Plan F and Plan G: the one difference
Medicare Supplement (Medigap) plans are standardized. Plan G from one insurance company covers the same gaps as Plan G from another; what differs is the premium and the company’s service. The same is true of Plan F.
Side by side, Plans F and G cover the same list of costs — the Part A hospital deductible, Part A coinsurance, Part B coinsurance and copays, the first three pints of blood, skilled nursing facility coinsurance, hospice coinsurance, Part B excess charges, and foreign travel emergency care — with a single exception:
| Cost | Plan F | Plan G |
|---|---|---|
| Part A deductible and hospital coinsurance | Covered | Covered |
| Part B coinsurance and copays (20% share) | Covered | Covered |
| Part B excess charges | Covered | Covered |
| Skilled nursing facility coinsurance | Covered | Covered |
| Foreign travel emergency (up to plan limits) | Covered | Covered |
| Medicare Part B annual deductible ($283 in 2026) | Covered | You pay it |
Source: Medicare.gov, Compare Medigap Plan benefits. Figures reflect 2026 and can change each year.
That is the whole difference. With Plan G, you pay the Part B deductible yourself once each calendar year — the first $283 of doctor and outpatient services that Medicare approves — and after that your coverage works the way Plan F does. Both plans cover Part B excess charges, which matters in California because the state does not prohibit doctors who don’t accept Medicare assignment from charging up to 15% above the Medicare-approved amount. (Plan N, by contrast, does not cover excess charges.)
Why Plan F is in a different position than it used to be
Federal law changed who can buy Plan F. People who first became eligible for Medicare on or after January 1, 2020 cannot buy Plan F or Plan C — the two plans that pay the Part B deductible. If you were eligible for Medicare before that date, you can still buy or keep Plan F.
The practical effect is that Plan F is now a closed group: no one new to Medicare joins it, so the people in it get older on average each year. Many analysts expect that to put upward pressure on Plan F premiums over time compared with Plan G, which continues to enroll people turning 65. That is a reasonable expectation, not a guarantee — premium changes depend on each insurer’s experience and are reviewed by the California Department of Insurance — but it is the main reason the “F to G” question comes up so often.
How to do the math for your own policy
You do not need a spreadsheet. Three numbers:
- Your current Plan F monthly premium.
- The Plan G premium you are quoted — from your current insurer or any other company offering Plan G in California.
- The Part B deductible: $283 in 2026, which works out to about $23.58 per month.
If the Plan G premium is lower than your Plan F premium by more than $23.58 a month, Plan G may cost less for the year even after you pay the deductible yourself. If the gap is smaller than that, Plan F may still be the better value for you this year. Either way, your doctors, your hospital access and your Part B benefits are identical under both plans, because the plans are standardized and Original Medicare is what pays the claims.
Two things people often overlook:
- The deductible only matters if you use Part B services. Most people on Medicare do, every year, so assume you will pay it.
- The gap tends to grow. The difference between F and G premiums at age 68 is often smaller than the difference at age 78. Looking only at this year’s quotes can understate what the switch may be worth over time.
The California Birthday Rule: how the switch actually works here
In most states, moving from one Medigap plan to another means answering health questions, and an insurer can decline you or charge more. California is different.
Under California Insurance Code section 10192.11, if you already have a Medigap policy, you get an annual window — beginning on your birthday — to switch to any Medigap plan with benefits equal to or lesser than your current plan, from any insurer that sells it, with no medical underwriting. The statute sets the window at 60 days or more, commencing with your birthday (the 60-day length has been law since January 1, 2020, when SB 407 replaced the earlier 30-day window). Sixty days is a floor, so some insurers open earlier or stay open longer; the notice your insurer must send you 30 to 60 days before the window opens states your exact dates.
Plan G has lesser benefits than Plan F (it drops the Part B deductible), so moving from F to G is exactly the kind of switch the Birthday Rule was written for. You can stay with your current company or shop every insurer offering Plan G in California, and none of them can ask about your health during the window.
A few details worth knowing:
- Timing. The window opens on your birthday. If you want the switch to take effect on a specific date, start comparing quotes a month or two before your birthday so the paperwork is ready.
- It is one-directional. The rule lets you move to equal or lesser benefits. If you later wanted to go back from G to F, that would be moving to richer coverage, which generally requires medical underwriting in California (outside of specific guaranteed-issue situations). Treat the switch as a long-term decision.
- Outside the window. You can apply to switch at any time of year, but outside your birthday window the insurer can require health questions. Some companies may allow a Plan F to Plan G change within the same company without underwriting — ask your insurer directly, and get the answer in writing.
- High-deductible Plan G. This version has a much lower premium in exchange for a larger annual deductible before the plan pays. It is also a “lesser benefit” plan for Birthday Rule purposes. It suits some people with low expected medical use; it is not a fit for everyone.
Our guide to the California Birthday Rule for Medigap walks through the window and the notice you will receive, and When can I change my Medigap plan in California? covers the other situations that allow a switch.
When keeping Plan F can make sense
Plan G is not automatically the right move. Keeping Plan F may be reasonable if:
- The premium gap between your Plan F and the Plan G quotes is smaller than the Part B deductible, so the switch would not save anything this year.
- You strongly prefer to have no out-of-pocket exposure at all for Part B services, and you are comfortable paying for that.
- You plan to re-check the quotes at your next birthday window rather than switching now. The Birthday Rule comes around every year.
What is not a good reason to switch is pressure. No one needs to decide in a phone call. If anyone tells you Plan F is “going away” for current policyholders, that is not accurate — people who were eligible before 2020 can keep it.
Frequently asked questions
- Can I switch from Plan F to Plan G without answering health questions in California?
- Yes, during your Birthday Rule window, the annual period of 60 days or more that begins on your birthday, you can move from Plan F to Plan G with any California insurer offering it, with no medical underwriting, because Plan G has lesser benefits than Plan F. Outside that window, the insurer may require health questions unless it offers a same-company exception.
- Is Plan G as good as Plan F?
- Both plans cover the same gaps in Original Medicare with one exception: Plan G does not pay the Part B annual deductible ($283 in 2026). Your choice of doctors and hospitals is the same under both, because Original Medicare pays the claims.
- Will my Plan F premium keep going up?
- No one can promise what any premium will do. Plan F is closed to people who became eligible for Medicare on or after January 1, 2020, and many analysts expect that to put upward pressure on its premiums over time relative to Plan G. Premium changes are filed by each insurer and reviewed by the California Department of Insurance.
- If I switch to Plan G, can I go back to Plan F later?
- If you were eligible for Medicare before 2020 you remain eligible to buy Plan F, but moving from G back to F is a move to richer coverage, which generally requires medical underwriting in California. Treat the switch as a long-term decision.
- Does switching from Plan F to Plan G change my Part D drug plan?
- No. Medigap plans do not include prescription drug coverage. Your Part D plan is separate and is reviewed during the Annual Enrollment Period (October 15 to December 7) each year.
Sources & official references
- Medicare.gov — Compare Medigap Plan benefits — which plans pay the Part B deductible; who can buy Plans C and F
- Medicare.gov — Medicare costs — 2026 Part B deductible
- Medicare.gov — Can I change my Medigap policy?
- California Insurance Code § 10192.11 — annual open enrollment period for Medigap policyholders beginning on the birthday; equal or lesser benefits; no underwriting
- California Department of Insurance — Guide to Medicare Supplement
- California HICAP — free Medicare counseling, 1-800-434-0222 (California’s State Health Insurance Assistance Program (SHIP))
Last reviewed: October 2026. Medicare figures reflect 2026 and can change annually; confirm current amounts at Medicare.gov. This article is educational and is not a recommendation to buy, keep or cancel any policy.
We do not offer every plan available in your area. Currently we represent 12 organizations which offer 442 products in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options.
For free counseling, California’s State Health Insurance Assistance Program (SHIP), known as the Health Insurance Counseling and Advocacy Program (HICAP), is available at 1-800-434-0222.
Matt Medicares Insurance is an independent insurance brokerage and is not affiliated with or endorsed by Medicare, the Centers for Medicare & Medicaid Services, or any government agency.
