Medicare Advantage

San Diego Medicare 2027: Key Enrollment Dates

People in San Diego can choose from 85 Medicare Advantage plans for 2027, against 93 this year. 26 of this year’s plans are gone, 18 are new to San Diego County, and 48 that continue have changed their premium, deductible, plan type or name, 20 of them under a new name.

Medicare in San Diego: Your 2027 Enrollment Deadline…

SAN DIEGO — With 65 Medicare Advantage plans available in San Diego County for 2027 from 15 carriers, local seniors have plenty to sort through. But before you compare a single plan, there's something more important to nail down: the calendar.

Medicare runs on strict windows. Miss one, and you may wait months — sometimes a full year — for another chance to make a change. Here's how the 2026–2027 timeline works for the more than 507,000 people age 65 and older living in San Diego County.

The Annual Enrollment Period: October 15 – December 7

This is the big one. During AEP, anyone with Medicare can:

• Switch from Original Medicare to a Medicare Advantage plan, or vice versa.
• Change from one Medicare Advantage plan to another.
• Join, drop, or switch a Part D prescription drug plan.

Whatever you choose during AEP takes effect January 1, 2027. If December 7 passes and you did nothing, you stay in your current coverage for another year — unless you qualify for a Special Enrollment Period (more on that below).

Because San Diego County has 65 Medicare Advantage plans on the shelf for 2027 — with 18 new plans, 26 not returning, and 20 renamed compared with 2026 — giving yourself a few weeks to compare is smart. Don't wait until the first week of December.

The Medicare Advantage Open Enrollment Period: January 1 – March 31

Think of this as a do-over — but only for people already enrolled in a Medicare Advantage plan on January 1.

During this window, you can:

• Switch to a different Medicare Advantage plan.
• Drop your Medicare Advantage plan and return to Original Medicare (and add a stand-alone Part D plan if you'd like).

You only get to use this window once. It's not open to people who stayed with Original Medicare during AEP. And it's not a chance to shop around endlessly — one change, then you're locked in until next AEP.

Turning 65? Your Initial Enrollment Period

If you're new to Medicare, your Initial Enrollment Period is a seven-month window built around your 65th birthday: the three months before your birth month, your birth month, and the three months after.

Sign up during the three months before you turn 65 and coverage starts the first day of your birthday month. Wait until later in the window and coverage can be delayed.

This is the window most people regret missing. If you don't have other qualifying coverage (like an active employer plan) and you skip Part B when first eligible, you could face a 10% Part B premium penalty for every 12 months you delayed — and that penalty lasts as long as you have Medicare. A similar penalty applies to Part D.

What if you miss a window? Special Enrollment Periods

Life happens. SEPs let you make changes outside the standard windows if you experience a qualifying event, such as:

• Moving out of your current plan's service area (including moving into or out of San Diego County).
• Losing employer or union coverage.
• Qualifying for Medicaid or Extra Help with drug costs.
• Your plan leaving Medicare or making a major change to its contract.

Most SEPs give you 60 days to act. If you think one applies to you, call 1-800-MEDICARE before assuming you're stuck.

How the 2027 rules interact with your timing

A few program-level facts worth knowing before you pick your enrollment date:

• The Part D out-of-pocket cap is $2,100 in 2026 and $2,400 in 2027. Once you hit it, you pay nothing for covered drugs the rest of the year.
• The maximum Part D deductible is $615 in 2026 ($700 in 2027).
• The coverage gap (the old "donut hole") is gone — Part D now has three phases.
• The Medicare Prescription Payment Plan lets you spread drug costs across the year in monthly installments. You can opt in when you enroll in a Part D plan.
• IRMAA income surcharges for higher earners begin above $109,000 for single filers in 2026.

Note: California has 10 stand-alone Part D plans for 2027, sold statewide — so if you have Original Medicare in San Diego County, you can join any of them for drug coverage. If you want Original Medicare plus stand-alone drug coverage, confirm your options directly on Medicare.gov before your window closes.

Where to get free, unbiased help in San Diego

You don't have to figure this out alone, and you shouldn't rely on a sales pitch to sort out your deadlines. Free, unbiased help is available:

• Medicare.gov — the official Plan Finder tool lets you compare every plan available at your ZIP code.
• 1-800-MEDICARE (1-800-633-4227) — 24/7, TTY 1-877-486-2048.
• California's SHIP program, known as HICAP (Health Insurance Counseling and Advocacy Program) — trained volunteers offer one-on-one counseling to San Diego County residents at no cost.