Medicare Supplement

Which Medigap plan letters can you buy in San Francisco, and how do they fit with Original Medicare?

If you live in San Francisco and you're pairing Medigap with Original Medicare, the first thing worth knowing is that the plans themselves are federally standardized. That means a Plan G from one company covers the same core benefits as a Plan G from another. What changes from company to company is the price, the customer service, and, in California, some extra state rules that can affect when and how you switch.

San Francisco is in San Francisco County, where Medigap policies are sold by private insurers approved to do business in California. Below is a plain-English walk-through of the plan letters you can shop today, how Medigap works alongside Part D drug coverage, and the state resources that can help you compare.

What Medigap does (and doesn't) do

Medigap — also called Medicare Supplement Insurance — is private coverage that pays some of the out-of-pocket costs Original Medicare leaves behind, like coinsurance and copayments. It only works with Original Medicare. If you're enrolled in a Medicare Advantage plan, you can't also use a Medigap policy.

A few things Medigap does not cover:

• Prescription drugs (that's Part D)
• Routine dental, vision, or hearing
• Long-term custodial care

Because Medigap doesn't include drugs, most people who choose this route also enroll in a stand-alone Part D plan.

The plan letters available to new enrollees in California

Medigap plans are labeled by letter, and every plan with the same letter offers the same core benefits no matter which company sells it. If you became eligible for Medicare on or after January 1, 2020, the letters open to you are:

• A
• B
• D
• G
• G-HD (a high-deductible version of Plan G)
• K
• L
• M
• N

Plans C and F remain available only to people who were eligible for Medicare before January 1, 2020. The table on this page lists every standardized letter side by side so you can see what each one covers.

We don't recommend one letter over another — the right fit depends on how often you expect to see doctors, your budget, and how comfortable you are with cost-sharing. The Medicare & You handbook and the Medicare.gov comparison tool walk through the benefits box by box.

How Medigap pairs with Part D

Medigap picks up gaps on the medical side. Part D handles prescriptions. Together with Original Medicare, that's usually the full package.

A few 2026 Part D facts worth keeping in mind as you shop:

• The Part D annual out-of-pocket cap is $2,100 in 2026.
• The maximum Part D deductible is $615.
• The old "donut hole" is gone; Part D now has three phases (deductible, initial coverage, and catastrophic).
• The Medicare Prescription Payment Plan lets you spread your drug costs across the year in monthly installments if you choose.
• IRMAA surcharges for higher-income enrollees start above $109,000 for a single filer in 2026.

You can enroll in or change a Part D plan during the Annual Enrollment Period, October 15 through December 7.

California rules that can shape your choice

California layers a few consumer protections on top of federal Medigap rules. The most talked-about is the state's "birthday rule," which gives current Medigap policyholders an annual window around their birthday to switch to another Medigap plan with equal or lesser benefits — generally without going through medical underwriting. The exact length of that window and the details of who qualifies are set by state law and can change, so confirm the current rules with an official source before you act.

There are also federal guaranteed-issue rights, such as during your 6-month Medigap Open Enrollment Period that starts when you're 65 or older and enrolled in Part B. Outside those windows, insurers in California may use medical underwriting to decide whether to sell you a policy and at what price.

Because pricing methods (community-rated, issue-age, or attained-age) affect how a premium changes over time, ask any company how its policy is priced before you buy. The California Department of Insurance publishes a Medigap rate guide that explains this in detail.

How to shop without getting overwhelmed

A short, orderly approach usually works best:

1. Decide whether you want Original Medicare + Medigap + Part D, or a Medicare Advantage plan. You can't combine Medigap with Advantage. 2. Pick the plan letter that matches how you use care. 3. Compare companies selling that letter in your San Francisco ZIP code — same benefits, different prices and service. 4. Enroll in a separate Part D plan.

Free, unbiased help is available. California's State Health Insurance Assistance Program (SHIP), known locally as HICAP, offers one-on-one counseling at no cost.