Understanding California Medicare Enrollment Periods
Navigating Medicare can feel like learning a new language — especially when it comes to enrollment periods. Missing a deadline could mean paying higher premiums or waiting months for coverage to begin. This guide breaks down California’s Medicare enrollment periods so you’ll know exactly when and how to take action.
What Is a Medicare Enrollment Period?
A Medicare enrollment period is a designated window of time when you can apply for, change, or drop your Medicare coverage. Each period serves a different purpose, depending on your situation — whether you’re new to Medicare, switching plans, or updating your prescription coverage.
Understanding these timelines helps you avoid late enrollment penalties and ensures you have the right coverage when you need it.
Initial Enrollment Period (IEP)
The Initial Enrollment Period is your first opportunity to sign up for Medicare. It starts three months before you turn 65, includes your birthday month, and ends three months after that month — giving you seven months total.
If you’re already receiving Social Security benefits, enrollment is automatic for Parts A and B. Otherwise, you’ll need to apply through the Social Security Administration (SSA).
Tip: Enroll early in your IEP to avoid delays in coverage.
General Enrollment Period (GEP)
If you missed your Initial Enrollment Period, the General Enrollment Period runs from January 1 to March 31 each year. Coverage begins July 1.
Keep in mind — you may face a late enrollment penalty for Part B if you didn’t qualify for a Special Enrollment Period.
Special Enrollment Period (SEP)
A Special Enrollment Period lets you sign up or make changes outside the usual windows if certain life events occur. Examples include:
Losing employer or union health coverage
Moving out of your plan’s service area
Qualifying for Medi-Cal (California’s Medicaid program)
SEPs help protect you from gaps in coverage when life changes unexpectedly.
Annual Enrollment Period (AEP)
The Annual Enrollment Period, also known as Open Enrollment, happens every year from October 15 to December 7. During this time, you can:
Switch from Original Medicare to a Medicare Advantage plan (Part C)
Change from one Medicare Advantage plan to another
Add, change, or drop a Part D prescription drug plan
Any changes you make take effect on January 1 of the following year.
Medicare Advantage Open Enrollment Period (MA OEP)
From January 1 to March 31, Medicare Advantage members have a separate window to switch to another Medicare Advantage plan or return to Original Medicare (with or without a Part D plan).
This period is ideal if you realize early in the year that your new plan doesn’t meet your expectations.
California’s Birthday Rule for Medigap
California has a unique Birthday Rule that allows Medicare Supplement (Medigap) policyholders to switch to an equal or lesser plan within 60 days of their birthday without medical underwriting.
This means you can upgrade or adjust your coverage each year, no questions asked — a great benefit not offered in many other states.
Stay On Top of Enrollment with Expert Help
Enrollment periods can feel overwhelming, but you don’t have to track them alone. Vizion Integrated Insurance Agency helps Medicare beneficiaries in California compare plans, understand timelines, and avoid costly mistakes.
Whether you’re enrolling for the first time or adjusting your coverage, our licensed Medicare specialists can walk you through every step.
