Medicare Supplement

Madison Medigap in 2027: how Wisconsin's own plan rules and rate filings work

MADISON, Wis. — If you buy or shop Medicare Supplement coverage in Madison this fall, the ground rules look a little different than they do almost anywhere else in the country. Wisconsin is one of three states that designs its own Medigap policies instead of using the federal A-through-N letters, and that shapes what you can compare, when premiums move, and how to find the right policy for 2027.

Medicare SupplementMadison, WI

Here is what is actually changing as the calendar turns, and what stays the same.

Wisconsin plays by its own Medigap rulebook

Most of the country compares Medigap policies by letter — Plan G, Plan N, and so on. Wisconsin does not. The state requires insurers to sell a standardized Basic Plan, which policyholders can build on with optional riders (for example, a Part A deductible rider or a Part B copay/coinsurance rider). Alongside the Basic Plan, Wisconsin offers 50% and 25% cost-sharing versions and a high-deductible plan.

That means when a friend in another state talks about "Plan G" or "Plan N," those exact policies are not what you shop for in Madison. Compare Wisconsin policies by their Wisconsin names, feature by feature and rider by rider.

The Part B deductible resets every January

Every Medigap policy is built around Medicare Part B, and the Part B deductible resets on January 1 each year. Whether your Wisconsin plan pays the Part B deductible for you depends on the riders you bought. Two things are worth remembering:

• The deductible amount is set nationally by CMS and updated each year at medicare.gov.
• Newer Medicare enrollees (people who first became eligible for Medicare on or after January 1, 2020) are not allowed to buy Medigap policies that cover the Part B deductible. That federal rule still applies inside Wisconsin's own plan design.

If you were eligible for Medicare before 2020, that restriction does not apply to you.

Rate-adjustment season: how to check what your premium is doing

Medigap premiums are not set by Medicare. Insurers file proposed rates with the Wisconsin Office of the Commissioner of Insurance (OCI), and OCI publishes a Medigap rate guide that shows sample premiums by company, age and ZIP code. If your renewal letter arrives and the number looks different than last year, that filing is where the change comes from.

Two practical steps before you renew:

1. Pull up the current OCI Medigap rate guide and compare your policy's premium against other Wisconsin-standardized policies in Dane County ZIP codes. 2. Run the same ZIP code through the Medicare.gov Medigap policy search to see every insurer licensed to sell to you.

Insurers entering or leaving the state

Medigap carriers move in and out of Wisconsin from year to year, and the current list changes. There is no single "official" carrier lineup we can quote here without risking staleness, so use the two live sources instead:

• Medicare.gov Medigap policy search — enter a Madison ZIP code to see every company currently offering Wisconsin Medigap policies to someone in your situation.
• Wisconsin OCI Medigap rate guide — the state's published comparison of premiums by company.

If you already have a policy and your insurer is exiting the Wisconsin market, they must notify you in writing. In that situation, you generally have guaranteed-issue rights to buy certain replacement coverage without medical underwriting — call your SHIP counselor before you make a move so you do not accidentally give up that protection.

Enrollment periods people mix up

Medigap runs on its own timeline, not the Medicare Advantage and Part D calendar:

• Medigap Open Enrollment is a one-time, six-month window that starts the month you are 65 or older and enrolled in Part B. During it, insurers cannot deny you or charge more based on health.
• Outside that window, you can apply anytime, but insurers in Wisconsin can generally use medical underwriting unless you have a guaranteed-issue right.
• Oct. 15–Dec. 7 and Jan. 1–March 31 are the Medicare Advantage and Part D windows. They do not restrict Medigap shopping.

For context on drug coverage that may run alongside a Medigap policy: in 2026, Part D has a $2,100 out-of-pocket cap, a maximum deductible of $615, and the old "donut hole" phase is gone. IRMAA surcharges for higher-income enrollees begin above $109,000 in income for a single filer.

What to do this fall in Madison

Madison is in Dane County. Medigap availability itself is licensed statewide, but premiums vary by ZIP code, so run the numbers with your actual address.

1. Read your renewal notice carefully and note any premium change effective January 1. 2. Compare your policy against Wisconsin's Basic Plan (with riders), 50% and 25% cost-sharing plans, and the high-deductible plan on Medicare.gov and in the OCI rate guide. 3. If you are thinking of switching, call Wisconsin's SHIP — the Medigap Helpline — before you cancel anything. Underwriting rules and guaranteed-issue rights can make or break a switch.