10/30/2026
If you have a Medicare Supplement, most of this month's Annual Enrollment noise isn't about you. Here's the part that is — and the California window that's yours instead.
What Annual Enrollment doesn't touch: your Supplement. The October 15 – December 7 window is for Medicare Advantage and Part D drug plans. It can't be used to change Medigap coverage, and nothing about your Supplement changes on January 1 just because the ads say "compare your plan."
What it does touch: your standalone Part D drug plan. That one deserves a look every fall — formularies, tiers and pharmacy networks reset each January, and swapping Part D plans doesn't affect your Supplement at all.
Your actual switching window is the California Birthday Rule. Every year, starting on your birthday, you have at least 60 days to switch to another Supplement with equal or lesser benefits — any company selling it in California, no health questions, no medical underwriting. Same plan letter with a different company is the classic move, because a Plan G is a Plan G no matter whose name is on the card; what differs is the premium. Your carrier is required to send a notice before your window opens, and 60 days is the legal minimum — some carriers allow longer.
Two cautions: the Birthday Rule is for people who already hold a Supplement — it isn't a way into your first one. And it only moves sideways or down in benefits, not up; richer coverage generally means health questions.
So this fall: review the Part D piece by December 7, and put your own birthday on the calendar for the Supplement piece.
The full Birthday Rule guide, with the window dates by birth month, is linked below.
I'm Matt Rolph, an independent licensed insurance broker serving Santa Barbara County and Southern California.
📞 805-322-8053
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Matt Medicares Insurance is a non-government entity, not affiliated with or endorsed by Medicare or any government agency. We do not offer every plan available in your area. Please contact Medicare.gov, 1-800-MEDICARE, or your local State Health Insurance Assistance Program (SHIP) for information on all of your options. CA Insurance License 4199527.
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California's Birthday Rule lets Medigap policyholders switch to equal-or-lesser plans without health questions each year. How the 60-day window works.