Medicare Supplement

Turning 65 in San Diego? Your 6-Month Medigap Window

San Diego is in San Diego County, where people on Original Medicare can round out their coverage with a Medicare Supplement Insurance policy — better known as Medigap. The policies sold here follow the same federal lettered menu used across most of the country, but California adds a few consumer rules of its own that can shape when you buy and how much you pay over time.

Medicare SupplementSan Diego, CA

If you are new to this, the short version is that Medigap does not replace Medicare. It sits alongside Original Medicare (Part A and Part B) and helps pay some of what Medicare leaves behind, like coinsurance and copays. It does not include drug coverage, so most people pair a Medigap policy with a stand-alone Part D plan.

The plan letters you can buy in California

Medigap is standardized by the federal government, so a Plan G from one company covers the same core benefits as a Plan G from another. What changes is the price and the company behind it — not the benefits inside each letter.

In California, people who become eligible for Medicare today can choose from these standardized plans:

• Plan A
• Plan B
• Plan D
• Plan G
• Plan G High Deductible
• Plan K
• Plan L
• Plan M
• Plan N

Plans C and F are still around, but only for people who were eligible for Medicare before January 1, 2020. If that is you, you may still be able to buy them; if you turned 65 more recently, they are off the menu.

Three states — Massachusetts, Minnesota and Wisconsin — standardize their Medigap policies differently. California is not one of them, so the federal letters above are what you will see here.

How Medigap pairs with Original Medicare and Part D

A Medigap policy only works if you have Original Medicare. Here is the usual pairing for a San Diego resident who does not want a Medicare Advantage plan:

• Part A and Part B (Original Medicare) pay first.
• A Medigap policy picks up some of the leftover costs, depending on the letter you choose.
• A stand-alone Part D plan handles prescriptions.

You cannot use a Medigap policy with a Medicare Advantage plan. If you are enrolled in Advantage and want to switch back to Original Medicare plus Medigap, the timing and your rights to be accepted depend on where you live and when you make the move.

The Part D piece for 2026

Because Medigap does not cover drugs, the Part D rules matter. A few 2026 figures worth knowing:

• The Part D out-of-pocket cap is $2,100.
• The Part D maximum deductible is $615.
• The old coverage gap (the "donut hole") is gone as of 2025 — Part D now has three phases.
• The Medicare Prescription Payment Plan lets you spread your drug costs across the year in monthly amounts instead of paying at the pharmacy counter.
• IRMAA surcharges on Part B and Part D premiums begin above $109,000 in income for a single filer.

You can join, switch or drop a Part D plan during the Annual Enrollment Period, October 15 through December 7.

California rules that shape your choice

California has some consumer protections that go beyond the federal floor. Two worth asking about:

• California uses a birthday rule that gives current Medigap enrollees a yearly window, tied to their birthday, to switch to certain other Medigap policies without new medical underwriting. The exact length of the window and which switches are allowed are set by state law and can change, so confirm the current rule before you rely on it.
• California also has rules about how insurers can price Medigap policies (for example, by age at purchase versus by current age). How a policy is priced now affects how the premium can grow later.

For the current details, the California Department of Insurance publishes a Medigap rate guide, and the state's Health Insurance Counseling and Advocacy Program (HICAP, California's SHIP) can walk you through your rights one on one — for free.

When you have the strongest right to buy

Your best shot at getting any Medigap policy you want, at the best rate the company offers, is your Medigap open enrollment period. This is a 6-month window that starts the first month you are both 65 or older and enrolled in Part B. During that window, companies cannot turn you down or charge you more because of your health.

Outside that window, unless you have a guaranteed issue right (for example, if certain other coverage ends), insurers in most states can use medical underwriting to decide whether to sell you a policy and at what price. California's birthday rule is one of the ways the state creates extra chances to switch, but it does not replace that first 6-month window.

How to compare policies in San Diego

There is no single "best" Medigap plan or company — the right fit depends on your health, your budget and how you feel about paying more up front versus more as you go. A few practical steps:

• Use the Medicare.gov Medigap policy search by ZIP code to see which insurers sell each lettered plan in San Diego and pull sample premiums.
• Read the California Department of Insurance's Medigap rate guide for a side-by-side look at how policies are priced.
• Call HICAP (California's SHIP) for unbiased help, or call 1-800-MEDICARE.
• When you are ready to compare specific quotes, ask each insurer how the policy is priced (issue-age, attained-age or community-rated), because that determines how the premium changes over time.

The table on this page shows the standardized letters available to new enrollees in California; use it as your starting point, then take those letters into the Medicare.gov search to see who sells them near you.