Medicare Advantage

What San Francisco Can Change During MA Open Enrollment

For 2027, San Francisco is looking at 46 Medicare Advantage plans: 7 new, 12 gone since 2026, and 35 still here but changed on premium, deductible, plan type or name, 13 of them under a new name. Below, how the lineup shifted in San Francisco County and what to compare, with no plan ranked or recommended.

San Francisco — If you woke up in January regretting the Medicare Advantage plan you picked in the fall, you are not stuck. The Medicare Advantage Open Enrollment Period runs January 1 through March 31, and it gives people already in a Medicare Advantage plan a second chance to make one change before the window closes.

This piece is about the calendar: which window applies to you, what you can and cannot do inside it, and what happens if you let a deadline slip past. San Francisco residents get the same federal timelines as the rest of the country, but the local landscape matters too — San Francisco is in San Francisco County, where plan choices are set at the county level.

Two windows, two very different jobs

It helps to keep the two main enrollment periods straight, because they do different things.

The Annual Enrollment Period (AEP) runs October 15 through December 7. It is the broad window — anyone with Medicare can join, switch, or drop a Medicare Advantage plan or a Part D drug plan during AEP. Whatever you choose takes effect January 1.

The Medicare Advantage Open Enrollment Period (MA OEP) runs January 1 through March 31. It is narrower. It is only for people who are already in a Medicare Advantage plan as of January 1. If you are in Original Medicare on January 1, this window is not for you.

Think of AEP as the planning season and MA OEP as the correction season.

What you can change between January 1 and March 31

If you are enrolled in a Medicare Advantage plan on January 1, during MA OEP you may:

• Switch from your current Medicare Advantage plan to a different Medicare Advantage plan (with or without drug coverage).
• Drop your Medicare Advantage plan and go back to Original Medicare (Parts A and B).
• If you return to Original Medicare, join a stand-alone Part D prescription drug plan.

You get one change during this window. Your new coverage starts the first day of the month after the plan gets your enrollment request, so making the switch in early January means coverage can begin as soon as February 1.

What you cannot do in this window

MA OEP is not a free-for-all. During January 1 – March 31 you cannot:

• Switch from Original Medicare to a Medicare Advantage plan (if you weren't already in one on January 1).
• Join a stand-alone Part D plan if you are staying in Original Medicare and were already in Original Medicare on January 1.
• Switch from one stand-alone Part D plan to another.

Those moves generally belong to AEP in the fall, or to a Special Enrollment Period if you qualify for one.

Missed the window? Here's what usually comes next

If March 31 comes and goes and you still are not happy with your coverage, your options narrow. In most cases you will need to wait until the next AEP (October 15 – December 7) to make a change, with coverage starting the following January 1.

The main exception is a Special Enrollment Period (SEP). SEPs are triggered by specific life events — moving out of your plan's service area, losing other creditable coverage, qualifying for Extra Help or Medicaid, or entering or leaving a nursing facility, among others. If one applies, you may be able to change plans outside the regular windows. A local counselor can help you confirm whether you qualify.

A few 2027 numbers worth knowing before you switch

If prescription drug costs are what is pushing you to make a change, keep these program-level figures in mind as you compare options:

• The Part D out-of-pocket cap is $2,100 for 2026.
• The maximum Part D deductible is $615 in 2026 ($700 in 2027).
• The old coverage gap (the "donut hole") has been eliminated since 2025, leaving three phases of drug coverage.
• The Medicare Prescription Payment Plan lets you spread your drug costs across the year in monthly payments instead of paying at the pharmacy counter.
• IRMAA income-related surcharges for Part B and Part D generally begin above $109,000 in income for a single filer in 2026.

These are federal figures — they apply the same way in San Francisco as everywhere else.

How to actually make the change

The cleanest way to compare plans available in San Francisco County is the Plan Finder at medicare.gov, which lets you enter your prescriptions and preferred pharmacies. You can also call 1-800-MEDICARE (1-800-633-4227), 24 hours a day, 7 days a week.

For free, unbiased, one-on-one help, California's SHIP program is called HICAP (Health Insurance Counseling and Advocacy Program). San Francisco residents can reach HICAP counselors through the California Department of Aging at 1-800-434-0222.