California Medigap Birthday Rule
The California Medigap Birthday Rule
The California Medigap Birthday Rule gives every Medicare Supplement policyholder in California a yearly do-over. For 60 days starting on your birthday, you can switch to a Medigap plan with equal or lesser benefits, from any insurance company that sells it, with no health questions, no medical underwriting, and no higher price because of your health.
The lead example is the switch Californians use most: Plan F to Plan G, a downgrade on paper (Plan G does not pay the Part B deductible) that often cuts the premium by far more than that deductible. The same rule covers switching your current plan to the same letter at a cheaper carrier, or stepping down from Plan G to Plan N. This page is the landing page for the rule; our Resources guide, the California Birthday Rule in 5 Minutes, tells the same story in short form.
Who can use the Birthday Rule
Two groups cannot use it. Medicare Advantage members are not Medigap policyholders, so the rule does not help someone leave Medicare Advantage for Medigap (guaranteed issue rights are the path for some of those moves, covered on the guaranteed issue page in this section). And first-time buyers have nothing to switch from; their no-questions window is the six month Medigap Open Enrollment Period that starts when they are 65 or older and on Part B.
- You live in California.
- You already have a Medigap (Medicare Supplement) policy in force. The rule is for policyholders only.
- You are switching to a plan with equal or lesser benefits than the one you have now.
- You apply inside the window: 60 days or more, starting on your birthday.
Equal or lesser benefits, in plain examples
- Plan F to Plan G: allowed. Plan G is lesser in one place only, the Part B deductible. This is the page most readers want next: see plan f vs plan g california for the switch math and steps.
- Plan G to the same Plan G at another carrier: allowed, and often the point. Identical coverage, lower premium.
- Plan G to Plan N: allowed. Plan N is lesser (copays, no excess charge coverage).
- Plan G to High Deductible Plan G: allowed. Lesser, because of the deductible.
- Plan N to Plan G: NOT allowed under this rule. That is an upgrade to richer benefits, and it needs underwriting or a guaranteed issue window.
- A standard plan and the Innovative version of the same letter (with added extras like vision or hearing) count as equal under California law, in either direction.
What to do inside your window
Miss the window and the same switch usually requires passing a carrier's health questions, with no promise of approval. The window returns next birthday, but rates and health can both move against waiting.
- Watch for your current carrier's letter. By law it must reach you 30 to 60 days before your window opens, and again on any premium or benefit change notice.
- Get quotes for the plan and carrier you want, priced for the effective date inside your window.
- Apply inside the 60 days and note that it is a Birthday Rule application.
- Confirm the new policy is issued and its effective date, then cancel the old policy so coverage is continuous.
Prefer the short version first? Read the California Birthday Rule in 5 Minutes in our Resources section. If your Medicare Advantage plan is ending instead, start with Medigap guaranteed issue in California.
Compare the plans
The switch math, the Birthday Rule steps, and the one-way warning.
Plan GThe most complete coverage for people new to Medicare, no visit copays.
Medigap guaranteed issue in CaliforniaThe other no-health-questions path, when a plan ends or leaves your area.
Back to the full comparison: Medicare Supplement plans in California.
Questions and answers
How long is the California Medigap Birthday Rule window?
At least 60 days, starting on your birthday, under California Insurance Code section 10192.11(h). Sixty days is the legal floor; the letter from your carrier states your exact window, and a few carriers allow longer.
Can I change insurance companies under the Birthday Rule?
Yes. The rule lets you buy the new policy from any issuer that sells it in California, not just your current company. Sideways switches to the same letter at a cheaper carrier are one of its main uses, because the benefits are standardized and only your premium changes.
Does the Birthday Rule work if I have a pre-existing condition?
Yes. Inside the window, an issuer may not deny the policy, delay its start, or price it because of your health status, claims history, or medical conditions, as long as you are covered by another Medigap policy at the time. That protection is the whole point of the rule for people whose health has changed since they first bought coverage.
Can I use the Birthday Rule to leave Medicare Advantage for Medigap?
No. You must already hold a Medigap policy to use it. People leaving a Medicare Advantage plan may have separate guaranteed issue rights instead, for example when the plan itself ends or leaves their area. Those rights, and their deadlines, are covered on the Medigap guaranteed issue page in this section.
Your birthday window is a deadline. Use it on purpose.
Call or text, Mon to Thu 9 AM to 8 PM, Fri 9 AM to 3 PM, Sat 9 AM to 2 PM PT
Talk it through with Eric before your window opens. We will compare your current plan against the equal or lesser options, price the switch, and handle the timing so there is no gap in coverage, at no cost to you.
Written by Eric Ullrich, licensed Medicare insurance agent, CA license #4551902, NPN 22200900. Last reviewed October 27, 2026. Medigap benefits on this page follow the federally standardized plan chart published by Medicare.gov. Sources: California Insurance Code section 10192.11 (Birthday Rule), California Department of Insurance, consumer guide to Medicare Supplement insurance, Medicare.gov, Compare Medigap plan benefits. Verify plan details with the carrier or at Medicare.gov before enrolling.