When is the Medicare Annual Enrollment Period for 2026?

The Medicare Annual Enrollment Period (AEP) runs October 15 through December 7 each year. During this window you can join, switch, or drop a Medicare Advantage or Part D plan, with changes taking effect January 1. It's the main time to review your coverage since plans change annually.

What happens if I miss my Medicare enrollment window?

Missing your enrollment window without other creditable coverage can trigger lifelong late-enrollment penalties. The Part B penalty adds 10% to your premium for each full 12-month period you delayed, permanently. Part D has its own penalty. These are avoidable with proper timing, which is why it helps to talk to an agent before you're eligible.

Can I change my Medicare Advantage plan after enrolling?

Yes. During the Medicare Advantage Open Enrollment Period (January 1 to March 31), if you're already in an Advantage plan you can make one change - switch to another Advantage plan or go back to Original Medicare and add a Part D plan. You can also make changes during the Annual Enrollment Period each fall.

What is a Special Enrollment Period for Medicare?

A Special Enrollment Period lets you enroll or change plans outside the standard windows due to a qualifying life event - such as losing employer coverage, moving to a new area, or losing other creditable coverage. These prevent penalties for people whose circumstances change. We help confirm whether you qualify and enroll you correctly.

California Medicare Guide

How Medicare Works New to Medicare / Turning 65 Parts A, B, C, D Advantage Plans Medigap Plans Advantage vs MedigapEnrollment PeriodsBirthday Rule (CA)Costs & Giveback

Medicare Enrollment Periods (2026)

Q: What is the Medicare Initial Enrollment Period?

Your Initial Enrollment Period (IEP) is a 7-month window around your 65th birthday: the 3 months before your birthday month, your birthday month, and the 3 months after. This is when you first enroll in Medicare Parts A and B and choose between Medigap plus Part D or a Medicare Advantage plan.

Key Takeaways

Initial Enrollment Period (IEP): the 7 months around your 65th birthday — your first chance to enroll.
Annual Enrollment Period (AEP): Oct 15 – Dec 7 each year — change Advantage/Part D plans for Jan 1.
Medicare Advantage Open Enrollment (OEP): Jan 1 – Mar 31 — one change if you're already in an Advantage plan.
Special Enrollment Periods (SEP): triggered by life events like losing employer coverage or moving.
Missing your enrollment window can cause lifelong late penalties on Part B and Part D.

California Medicare Advantage Open Enrollment 2027 - Watch on YouTube

Medicare has specific enrollment windows — and missing them can mean lifelong penalties. Knowing which period applies to you is essential. Here are the four you need to understand.

Initial Enrollment Period (IEP)

Your first window at 65

A 7-month window: the 3 months before your 65th birthday month, your birthday month, and the 3 months after. This is when you first sign up for Parts A and B and choose your path. Enrolling early (before your birthday month) means coverage starts sooner.

Annual Enrollment Period (AEP)

Oct 15 – Dec 7 every year

The big annual window. You can join, switch, or drop a Medicare Advantage plan or Part D drug plan. Changes take effect January 1. This is the time to review — plans change every year.

Medicare Advantage Open Enrollment (OEP)

Jan 1 – Mar 31

If you're already in a Medicare Advantage plan, you get one change during this window — switch to another Advantage plan or return to Original Medicare (and add a Part D plan). It's a second chance if your AEP choice isn't working out.

Special Enrollment Periods (SEP)

Losing employer coverage

Retiring or losing job-based coverage triggers a window to enroll without penalty.

Moving

A permanent move to a new area with different plan options opens a Special Enrollment Period.

Other qualifying events

Losing other creditable coverage, plan changes, and certain life events can also qualify.

Don't trigger lifelong penalties

If you don't sign up for Part B or Part D when first eligible — and don't have other creditable coverage — you can face permanent late-enrollment penalties added to your premiums for life. The Part B penalty is 10% for each 12-month period you delayed. These are avoidable with the right timing. If you're turning 65, still working, or losing coverage, talk to us first — we make sure you enroll at the right time, free.