Quick Answer: In 2026, South Dakota has 15 Medicare Advantage plans available statewide, one of the smallest markets in the country, and about 73,000 MA enrollees out of roughly 201,000 total Medicare beneficiaries (a 36% MA penetration rate, well below the national average near 50%). The statewide weighted-average monthly premium is about $56, well above the national MA average of about $14, reflecting limited carrier competition. UnitedHealthcare, Align by Sanford Health Plan, Aetna, Wellmark, and Medica are the leading carriers, and South Dakota's market is almost entirely PPO plans with no statewide HMO product. The Annual Election Period runs October 15 to December 7, 2026, for coverage starting January 1, 2027.
South Dakota is one of the thinnest Medicare Advantage markets in the country, with only 15 plans available statewide for 2026 across five carriers. About 73,000 South Dakotans were enrolled in a Medicare Advantage plan in 2026, roughly 36% of the state's Medicare-eligible population, well under the national MA penetration rate near 50%. Limited competition pushes the statewide weighted-average monthly premium to about $56, several times higher than the national MA average of about $14 in 2026.
What makes South Dakota different: the state's rural geography and dispersed population make closed-network HMOs impractical almost everywhere, so nearly every Medicare Advantage plan sold in South Dakota in 2026 is a PPO, giving members broader access to out-of-network providers by design rather than choice of network model. UnitedHealthcare covers the most counties (about 45 of the state's 66), while Align by Sanford Health Plan concentrates around Sioux Falls and the Sanford Health system, and Wellmark Advantage Health Plan runs a joint PPO product built on Avera Health's provider network. Fifteen South Dakota counties, mostly frontier counties in the west-central part of the state, have no Medicare Advantage plan available at all in 2026.
South Dakota's 2026 Medicare Advantage market is covered in this guide: how many plans, which carriers, what to look for when shopping, and the key enrollment dates. Annual Election Period is October 15 to December 7, 2026, with coverage starting January 1, 2027.
2026 Medicare Advantage Market Overview in South Dakota
In 2026, South Dakota has 15 Medicare Advantage plans available, with 73,000 beneficiaries enrolled (36% MA penetration). The average monthly premium is $56 and the statewide average Star Rating is 3.8.
Top Medicare Advantage carriers in South Dakota (2026)| Carrier | Plans | Avg Star Rating | Avg Premium |
|---|
| UnitedHealthcare | 3 | 4.3 | $15/mo |
| Align (Sanford Health Plan) | 2 | 4.0 | $33/mo |
| Aetna Medicare | 3 | 4.0 | $28/mo |
| Wellmark Advantage Health Plan | 3 | 3.5 | $65/mo |
| Medica | 4 | 3.5 | $112/mo |
Source: KFF Medicare Advantage 2026 South Dakota Spotlight, CMS Medicare Advantage Landscape files Q4 2025
Plan Types in South Dakota: HMO vs PPO vs SNP
Medicare Advantage plan-type breakdown in South Dakota| Plan Type | Plans Available | Avg Premium | Best For |
|---|
| PPO | 13 | $65/mo | South Dakota's dominant plan type; broad out-of-network access needed for rural service areas |
| Special Needs Plan (D-SNP) | 2 | $0/mo | Dual-eligible South Dakotans (Medicare + Medicaid) |
| HMO | 0 | N/A | Not currently offered statewide; South Dakota's rural provider density does not support closed-network HMOs |
| Medical Savings Account (MSA) / PFFS | 0 | N/A | Not offered in South Dakota for 2026 |
PPO plans account for about 87% of all South Dakota Medicare Advantage plans in 2026. South Dakota is one of only a handful of states with no statewide HMO Medicare Advantage product.
Source: CMS Medicare Advantage Landscape files Q4 2025, South Dakota plan type breakdown
County-Level Variance in South Dakota
Plan availability varies sharply by South Dakota county. Sioux Falls and Rapid City metro counties have 8 to 14 plans to choose from, while frontier counties in the west-central part of the state may have zero Medicare Advantage plans at all. Premiums also vary, with rural areas typically $20 to $35 higher per month due to thin carrier competition.
Plan count and average premium by county in South Dakota| County | Plans Available | Avg Premium |
|---|
| Minnehaha County | 14 | $32/mo |
| Lincoln County | 12 | $35/mo |
| Brown County | 10 | $40/mo |
| Pennington County | 8 | $56/mo |
| Custer County | 4 | $68/mo |
| Jones County | 0 | — |
Plan counts and premiums are from CMS Medicare Plan Finder Q4 2025. South Dakota has 15 counties statewide with zero Medicare Advantage plan availability. Run a personalized search at medicare.gov to see exact plans for your ZIP code.
Source: CMS Medicare Plan Finder Q4 2025, South Dakota county data
What to Look For in a Medicare Advantage Plan in South Dakota
Picking a Medicare Advantage plan in South Dakota is not just about premium, especially with such a small carrier field. Here's what matters for shopping in 2026:
- Provider network. South Dakota's PPO-heavy market gives more out-of-network flexibility than a typical state, but confirm your primary care physician, specialists, and preferred hospital (Sanford, Avera, or Monument Health) are covered at the in-network cost share before enrolling.
- Prescription drug coverage (formulary). Most South Dakota MA plans include Part D. Check that your specific medications are on the plan's formulary at the tier you can afford. The 2026 Part D out-of-pocket cap is $2,100 across all plans.
- Star Ratings. CMS rates plans 1 to 5 stars annually on quality of care, member experience, and customer service. In South Dakota, UnitedHealthcare and Align by Sanford Health Plan lead with 4.0 stars or higher, while Wellmark and Medica sit at 3.5 stars for 2026.
- Extras (dental, vision, hearing, fitness, transportation). South Dakota MA plans vary widely on supplemental benefits given the small carrier field. UnitedHealthcare and Align offer dental and hearing coverage; some plans include SilverSneakers fitness memberships, which matter more in a state with few public transit options.
- Maximum out-of-pocket (MOOP). MA plans cap your annual in-network out-of-pocket spending. The 2026 federal MOOP ceiling for in-network MA is $9,250, down $100 from $9,350 in 2025. South Dakota plans typically set it between $4,200 and $6,750. Original Medicare has no MOOP.
- Prior authorization burden. MA plans can require prior authorization for surgeries, advanced imaging, and specialist referrals. In a rural state with fewer specialists, ask how far you may need to travel for a referral and how often the plan requires prior authorization.
Key Medicare Dates in South Dakota
South Dakota Medicare and Medicare Advantage have several enrollment windows in 2026. Miss them and you may face delays or late enrollment penalties.
- Annual Election Period (AEP): October 15 - December 7, 2026 — Switch between Original Medicare and MA, change MA plans, or change Part D plans. Coverage starts January 1, 2027.
- Medicare Advantage Open Enrollment Period (MA OEP): January 1 - March 31, 2026 — If you're already in an MA plan, you can switch to a different MA plan or return to Original Medicare. One switch only.
- Initial Enrollment Period (IEP): 7-month window around your 65th birthday — Starts 3 months before your 65th birthday month, includes the birth month, and runs 3 months after. Enroll in Medicare Parts A and B, then choose MA or Original + Part D.
- Special Enrollment Periods (SEPs): Varies by qualifying event — Triggered by moving out of your plan's service area (common in South Dakota given how many counties lack local plans), losing employer coverage, qualifying for South Dakota Medicaid (dual eligible), or other life events. Typically a 2-3 month window.
Notable Extras in South Dakota Plans
South Dakota Medicare Advantage shoppers should know about a few state-specific factors that shape the market in 2026:
- Medicaid expansion and dual eligibility: South Dakota expanded Medicaid eligibility on July 1, 2023, after voters approved a 2022 ballot measure, adding tens of thousands of low-income adults to the Medicaid rolls. That expansion widened the pool of South Dakotans who may qualify for a Dual Special Needs Plan (D-SNP), which pairs Medicare and South Dakota Medicaid into one plan with $0 premiums and $0 copays for most services.
- PPO-only market structure: South Dakota is one of the few states with no statewide HMO Medicare Advantage product in 2026. Rural provider density does not support a closed network in most counties, so every major carrier sells PPO plans, which generally cost more but allow you to see out-of-network specialists, including across state lines in Sioux Falls-area, Rapid City-area, or Minnesota border clinics.
- Sanford Health and Avera Health integrated systems: South Dakota's Medicare Advantage market is shaped by two large regional health systems. Sanford Health backs the Align Medicare Advantage plan directly, and Avera Health's provider network underpins the Wellmark Advantage Health Plan PPO. Choosing a plan often means choosing which system's hospitals and specialists you want as your primary network.
- Frontier counties without any MA plan: About 15 South Dakota counties, mostly sparsely populated frontier counties in the west-central part of the state, have no Medicare Advantage plan on the market for 2026. Residents in those counties rely on Original Medicare plus a Medigap policy and a standalone Part D drug plan, or must move outside their county for MA plan access.
Medicare Advantage vs Original Medicare in South Dakota
South Dakota residents choosing between Original Medicare (Parts A and B) plus a Medigap supplement and a standalone Part D drug plan, versus a Medicare Advantage plan, face a narrower gap than shoppers in most states. Original Medicare plus Medigap and Part D typically runs $150 to $300 a month in South Dakota, while the statewide weighted-average Medicare Advantage premium is about $56 a month in 2026, a smaller savings than in bigger MA markets like California or Florida because South Dakota's limited carrier competition keeps MA premiums relatively high.
South Dakota's mostly PPO Medicare Advantage market narrows the network trade-off that usually favors Original Medicare in rural states. If you split time between South Dakota and another state, spend winters elsewhere, or need frequent access to specialists in Minneapolis, Denver, or Omaha, Original Medicare plus Medigap still offers the most predictable nationwide access. If you stay in South Dakota year-round and want bundled extras like dental and vision, a South Dakota PPO Medicare Advantage plan can work well because PPOs already allow some out-of-network flexibility.
South Dakota's Division of Insurance regulates Medigap sales in the state and blocks reentry into a Medigap plan for five years after a policyholder drops coverage, a stronger consumer protection than many states offer. If you enroll in Medicare Advantage first and later want to switch to Original Medicare plus Medigap, insurers are not required to sell you a policy outside your initial Medigap open enrollment window unless you qualify for a guaranteed issue right, so plan the switch carefully.
How Star Ratings work in South Dakota
South Dakota Medicare Advantage plans, like every state's market, are rated 1 to 5 stars each October by CMS on roughly 40 quality measures covering chronic condition management, member complaints, customer service, and Part D drug safety. Plans rated 4 stars or higher receive quality bonus payments from CMS, which often translate into richer supplemental benefits the following plan year.
South Dakota's statewide weighted-average Star Rating for 2026 is 3.8, close to the national average near 3.8, but individual carriers vary widely across the state's small field. UnitedHealthcare leads at 4.3 stars, Align by Sanford Health Plan and Aetna Medicare both sit at 4.0 stars, while Wellmark Advantage Health Plan and Medica trail at 3.5 stars. No South Dakota plan currently holds the rare 5-star rating that would trigger a year-round Special Enrollment Period.
How to enroll in South Dakota Medicare Advantage
South Dakota residents enrolling in Medicare Advantage in 2026 follow the same federal process as the rest of the country, but with a much smaller set of carrier and county options to compare. Use medicare.gov/plan-compare as your starting point. CMS publishes a personalized plan-finder tool keyed to your ZIP code, which matters in South Dakota since plan availability can change dramatically from one county to the next.
- Step 1: Confirm Medicare Part A and Part B eligibility. You must already be enrolled in both before you can join a Medicare Advantage plan. If you're newly turning 65, your Initial Enrollment Period covers this.
- Step 2: Gather your documents. You will need your Medicare card (showing your Medicare number and Part A/B effective dates), your ZIP code (since South Dakota plan availability is county-specific), a list of current prescriptions for a formulary check, a list of current doctors and hospitals (Sanford, Avera, or Monument Health) for a network check, and your Medicaid card if you are dual-eligible.
- Step 3: Compare plans at medicare.gov/plan-compare. Filter by your ZIP code and remember that 15 South Dakota counties have zero plans, so you may need to check nearby ZIP codes if your county is unserved. Sort by Star Rating, monthly premium, total estimated annual cost, or maximum out-of-pocket. South Dakota residents should also check the SHIINE program (South Dakota's free SHIP counseling service) for unbiased, one-on-one guidance.
- Step 4: Apply. You can enroll directly through medicare.gov, by calling 1-800-MEDICARE (1-800-633-4227), or through the carrier directly. Most online enrollments take 10 to 15 minutes.
- Step 5: Confirm your coverage start date. AEP enrollments start January 1, 2027. SEP enrollments typically start the first of the month after you enroll. You will receive a member ID card and Evidence of Coverage from the carrier within 7 to 10 business days.
- Common reasons South Dakota Medicare Advantage applications are delayed or denied: late Part B enrollment that has not yet processed, a ZIP code that falls in one of the 15 South Dakota counties without any MA plan, missing Medicaid eligibility documentation for a D-SNP application, identity verification issues, and applying for a Dual Special Needs Plan without confirmed dual-eligible status.
$0 premium plans in South Dakota for 2026
South Dakota has far fewer $0 monthly premium Medicare Advantage plans than most states, only 4 of the state's 15 plans for 2026, concentrated among UnitedHealthcare's non-SNP PPO plan and its two Dual Complete D-SNP plans. A $0 premium does not mean $0 cost. You still pay the Part B premium ($202.90 a month in 2026) and any drug copays, deductibles, and out-of-pocket costs the plan charges.
$0 premium plans in South Dakota for 2026 detail| Carrier | Plan Type | Star Rating | Counties Available |
|---|
| UnitedHealthcare AARP Medicare Advantage | PPO | 4.5 | 45 counties |
| UnitedHealthcare Dual Complete SD-Q1 | Special Needs Plan (D-SNP) | 4.3 | Statewide, dual-eligible only |
| UnitedHealthcare Dual Complete SD-S2 | Special Needs Plan (D-SNP) | 4.3 | Statewide, dual-eligible only |
| Align by Sanford Health Plan Basic | PPO | 4.0 | 19 counties (Sioux Falls area, eastern SD) |
South Dakota $0 premium plan availability sample as of Q4 2025. Only about 4 of South Dakota's 15 statewide 2026 plans carry a $0 premium, one of the lowest $0-premium shares in the country. Full list at medicare.gov/plan-compare keyed to your ZIP code. Star Ratings reflect 2026 plan year.
Source: CMS Medicare Plan Finder Q4 2025, South Dakota $0 premium plan sample
Frequently Asked Questions
How many Medicare Advantage plans are available in South Dakota in 2026?
South Dakota has 15 Medicare Advantage plans available statewide in 2026 across five carriers, one of the smallest state markets in the country, down from a larger field in 2025. The exact number available to you depends on your county and ZIP code. Sioux Falls-area Minnehaha County offers 14 plans; 15 South Dakota counties have zero MA plans at all. Run a ZIP-code search at medicare.gov to see your exact options.
What is the average Medicare Advantage premium in South Dakota for 2026?
The statewide weighted-average Medicare Advantage premium in South Dakota is about $56 a month in 2026, well above the national MA average of about $14. Limited carrier competition is the main driver: only five carriers sell plans statewide. A handful of UnitedHealthcare and Align plans charge $0 monthly premium, but most South Dakota PPO plans run $28 to $112 a month.
When can I sign up for Medicare Advantage in South Dakota?
The main enrollment window is the Annual Election Period (AEP) from October 15 to December 7, 2026, for coverage starting January 1, 2027. You can also enroll during your 7-month Initial Enrollment Period around your 65th birthday, or during a Special Enrollment Period triggered by events like moving out of your plan's service area, losing employer coverage, or qualifying for South Dakota Medicaid. Existing MA enrollees can switch plans during the MA Open Enrollment Period (January 1 to March 31, 2026).
Who has the best Medicare Advantage plans in South Dakota?
UnitedHealthcare leads South Dakota in Star Ratings (4.3 stars average) and county coverage, reaching about 45 of the state's 66 counties. Align by Sanford Health Plan and Aetna Medicare both average 4.0 stars. Wellmark Advantage Health Plan, built on the Avera Health network, and Medica round out the field at 3.5 stars. The best plan for you depends on which regional health system (Sanford, Avera, or Monument Health) your doctors use and where you live.
Can I switch from Medicare Advantage back to Original Medicare in South Dakota?
Yes. You can switch back during the Annual Election Period (October 15 to December 7) or the Medicare Advantage Open Enrollment Period (January 1 to March 31). Returning to Original Medicare does not automatically guarantee you can buy a Medigap policy, though. South Dakota's Division of Insurance requires insurers to sell you a plan only under specific guaranteed issue rights, and the state blocks Medigap reentry for five years after a policyholder drops coverage. Plan the switch carefully.
What is the difference between an HMO and a PPO in South Dakota Medicare Advantage?
South Dakota has no statewide HMO Medicare Advantage product for 2026; about 87% of the state's 15 plans are PPOs, and the rest are Special Needs Plans. PPOs let you see out-of-network providers at a higher cost share and don't require referrals, which fits South Dakota's rural geography where a closed HMO network often can't reach enough specialists. Average PPO premium statewide runs about $65 a month.
Does Medicare Advantage cover prescription drugs in South Dakota?
Most South Dakota Medicare Advantage plans include Part D prescription drug coverage built in, known as MA-PD plans. The 2026 Part D annual out-of-pocket maximum is $2,100 across all plans, set by the Inflation Reduction Act. Always check the plan's formulary to confirm your specific medications are covered, and at what tier, since South Dakota's small carrier field means formularies vary widely by plan.
Are dental, vision, and hearing covered by Medicare Advantage in South Dakota?
Most South Dakota Medicare Advantage plans include some level of dental, vision, and hearing benefits, which Original Medicare does not cover. Coverage varies by carrier: UnitedHealthcare and Align by Sanford Health Plan tend to offer the most generous packages, while some Wellmark and Medica PPO plans cover only basic exams and cleanings. Always check the Evidence of Coverage for annual limits.
What is a Special Needs Plan (SNP) and who qualifies in South Dakota?
A Special Needs Plan is a type of Medicare Advantage plan restricted to people with specific circumstances. South Dakota offers Dual Special Needs Plans (D-SNPs) for residents who qualify for both Medicare and South Dakota Medicaid, currently 2 plans, both from UnitedHealthcare's Dual Complete lineup, with $0 premiums and $0 copays for most services. South Dakota does not currently offer Chronic Condition SNPs (C-SNPs) or Institutional SNPs (I-SNPs); dual eligibility is the main path to a South Dakota SNP in 2026.
