Medicare Supplement

Same Medigap Plan G in Sioux Falls: how to compare 27 insurers side by side

In Sioux Falls, a shopper looking at Medicare Supplement Insurance — better known as Medigap — has an unusually crowded field to sort through. Sioux Falls sits in Minnehaha County, where the Medicare.gov Medigap search (ZIP 57103) currently lists 27 insurers offering standardized plans. Every one of those insurers sells the exact same coverage under any given plan letter. What actually changes from company to company is how they price it, whether they ask health questions, and what extras they attach around it.

Medicare SupplementSioux Falls, SD

This guide walks through how to compare the same plan letter — a Plan G with one insurer against a Plan G with another, for example — without getting lost in marketing.

The same letter means the same coverage

This is the single most important idea in Medigap shopping: a Plan G is a Plan G. The federal government standardized these plans, so the benefits inside a Plan N sold by one insurer are identical to the benefits inside a Plan N sold by another. Two policies with the same letter cover the same share of your Part A and Part B cost-sharing, in the same way, at any doctor or hospital that accepts Original Medicare.

That means comparing insurers is not about finding a "better" Plan G. It is about finding an insurer whose price, pricing method, service and stability you are comfortable with for the same coverage.

The table below lists every insurer selling Medigap in South Dakota and the plan letters each one offers. In Minnehaha County, that pool includes household names like AARP - UnitedHealthcare Insurance Company, Humana (Humana Insurance Company), Mutual of Omaha (Mutual of Omaha Insurance Company), State Farm Mutual Automobile Insurance Company, Wellmark BlueCross BlueShield of South Dakota, and regional carriers such as Avera Health Plans, Inc. and South Dakota Farm Bureau Health Plans, alongside many national insurers.

The three pricing methods to ask about

When you call an insurer or agent, ask which of these three methods the company uses in South Dakota. It shapes how your premium behaves over time.

• Attained-age rated. The premium is based on your current age and generally goes up as you get older, in addition to any general rate increases.
• Issue-age rated. The premium is based on your age when you first bought the policy. It does not go up just because you had a birthday, though it can still rise with general increases.
• Community rated (also called "no-age rated"). Everyone who has the policy pays roughly the same premium regardless of age, though general increases can still apply.

None of these methods is automatically "cheaper." An attained-age policy can start lower and rise faster; an issue-age or community-rated policy can start higher and hold steadier. What matters is the price you will pay not just this year but ten years from now.

Rate history: the number companies do not put on the brochure

Two insurers can quote similar first-year premiums for the same Plan G and end up in very different places five years later. That is why rate history matters.

South Dakota's Division of Insurance publishes a Medigap rate comparison guide that shows current premiums by insurer and, in some editions, recent increases. You can also ask any insurer or agent for the company's rate-increase history in South Dakota for the specific plan letter you are considering. A steady pattern of modest increases is a different story than a couple of large jumps.

Household discounts and other structural differences

Some insurers offer a household or spousal discount — a small percentage off the premium if you live with another adult, or if a spouse also enrolls. The size of the discount and the rules for qualifying (married, living together, both enrolled with the same company, etc.) vary by insurer and are worth asking about directly.

Insurers may also differ on:

• Whether they include any small extras (for example, wellness or vision programs) around the standardized medical benefits.
• How they handle billing, autopay and customer service.
• How long they have been selling Medigap in South Dakota.

None of these change the medical coverage of the plan letter, but they can matter to your day-to-day experience.

Underwriting: when insurers can ask about your health

During your six-month Medigap Open Enrollment Period — which starts the month you are 65 or older and enrolled in Part B — insurers in South Dakota must sell you any Medigap plan they offer at their standard rate, regardless of your health. This is called guaranteed issue.

Outside that window, and outside a handful of federal guaranteed-issue situations (for example, if your Medicare Advantage plan leaves your area), insurers in South Dakota can use medical underwriting. That means they can ask health questions and either charge more or decline to sell you the policy. Underwriting rules can vary from insurer to insurer, so if you are switching Medigap plans later, ask each company how they would evaluate your application before you cancel any existing coverage.

Which plan letters you can actually buy today

People newly eligible for Medicare today can choose from Plans A, B, D, G, G-HD, K, L, M and N. Plans C and F remain available only to people who were eligible for Medicare before January 1, 2020. Not every insurer sells every letter — for example, some Sioux Falls-area insurers focus on Plans A, F, G and N, while others carry a broader lineup that includes high-deductible G, K and L. The table on this page shows the letters each insurer offers.

Also keep in mind that Medigap works alongside Original Medicare and does not include Part D drug coverage. If you take prescriptions, you will pair a Medigap plan with a separate Part D plan, which has its own 2026 rules: a $615 maximum deductible, a $2,100 out-of-pocket cap, and an optional Medicare Prescription Payment Plan that lets you smooth drug costs across the year.

How to compare in practice

A simple side-by-side approach works well:

1. Pick one plan letter you want to compare (many South Dakota shoppers focus on G, high-deductible G, or N). 2. Use the Medicare.gov Medigap policy search for ZIP 57103 to pull the list of insurers selling that letter in Minnehaha County. 3. Check the South Dakota Division of Insurance Medigap rate guide for current premiums and any published rate history. 4. Call two or three insurers or an independent agent and ask: pricing method, most recent rate increases, household discount rules, and underwriting rules if you are past your Open Enrollment window. 5. Confirm what you learn with your local SHIINE counselor (South Dakota's State Health Insurance Assistance Program) before you enroll.