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Medicare Advantage Enrollment Tracker · South Dakota

Medicare Advantage Enrollment in South Dakota

South Dakota had 72,849 Medicare Advantage members in September 2026, by the CMS county file, which includes employer group plans. That is down 3.6% from Sep 2025, while the nation grew 2.0%. South Dakota ranks 46th by members and holds 0.2% of the national total.

Medica leads with 58.9% of members who have a carrier label (contract file, September 2026). Among individual plans, which leave out employer group coverage, enrollment is down 2.6% in the 12 months to September 2026.

By Senior Deal Club Standards Desk · Data as of September 2026 · Editorial policy

Data as ofCMS public files, monthly snapshot

  • These totals include employer and union group plans.
    Why this matters

    The CMS contract and county files count group plans that retirees get through a former employer. They are not plans you can pick on your own. Counts here are larger than the individual-plan counts on county pages.

  • Some months are missing from the source.
    Why this matters

    CMS did not publish every month. Lines break at a missing month instead of guessing a value. A dotted line, where shown, only joins the two sides.

South Dakota at a glance

Medicare Advantage members

72,849

South Dakota members by month: from 60.4K in Jan 2023 to 72.8K in Sep 2026

County file · Sep 2026. Includes employer group plans. Rank: 46.

County file · Sep 2026
CMS state, county and plan-type file (SCP). The same plans split by state and county, with employer and union group plans included. CMS hides counts of 10 or fewer.

12-month change

-3.6%

down 3.6 percent vs Sep 2025

County file · Sep 2026. National: +2.0%.

Share of national total

0.2%

County file · Sep 2026. Of jurisdictions that report every month.

Individual plan members

68,204

Individual MA · Sep 2026. Employer group plans left out.

Individual MA · Sep 2026
Individual Medicare Advantage plans (IND), from county data. Employer and union group plans are left out, so counts are smaller than in the other two files.

Largest carrier

Medica

58.9% of members with a carrier label. Contract file · Sep 2026.

South Dakota members by month

Medicare Advantage members in South Dakota

Members, by month.

County file · Sep 2026
CMS state, county and plan-type file (SCP). The same plans split by state and county, with employer and union group plans included. CMS hides counts of 10 or fewer.
Medicare Advantage members in South DakotaLine chart, January 2023 to September 2026. South Dakota: 72.8K in September 2026. Shaded bands mark months with no data.60K65K70K75K80K2023202420252026South Dakota72.8K
Medicare Advantage members in South DakotaLine chart, January 2023 to September 2026. South Dakota: 72.8K in September 2026. Shaded bands mark months with no data.60K65K70K75K80K20232025South72.8K
  • South Dakota
  • Shaded: no data that month
View the data table
Medicare Advantage members in South Dakota: values by month
MonthSouth Dakota
Sep 202672.8K
Aug 202672.8K
Jul 202672.6K
Jun 202672.5K
May 202672.4K
Apr 202672.3K
Mar 202672K
Feb 202671.3K
Jan 202667.8K
Dec 202575.9K
Nov 202575.8K
Oct 202575.7K
Sep 202575.6K
Aug 202575.4K
Jul 202575.1K
Jun 202574.9K
May 202574.7K
Apr 202574.5K
Mar 202574.2K
Feb 202573.8K
Jan 202572.1K
Dec 202471.6K
Nov 202471.5K
Oct 202471.3K
Sep 202471.1K
Aug 202470.8K
Jul 202470.5K
Jun 202470.3K
May 202470.1K
Apr 202469.9K
Mar 202469.6K
Feb 202468.4K
Jan 202467.9K
Dec 2023–
Nov 202365.3K
Oct 202365.1K
Sep 202364.7K
Aug 202364.4K
Jul 2023–
Jun 202363.8K
May 202363.5K
Apr 202363K
Mar 202362.6K
Feb 202362.1K
Jan 202360.4K

County file · Sep 2026. Employer group plans included.

South Dakota and the nation, Jan 2023 = 100

Each line is members divided by members in the start month, times 100.

County file · Sep 2026
CMS state, county and plan-type file (SCP). The same plans split by state and county, with employer and union group plans included. CMS hides counts of 10 or fewer.
South Dakota and the nation, Jan 2023 = 100Line chart, January 2023 to September 2026. South Dakota: 120.5 in September 2026. National (same jurisdictions each month): 117.8 in September 2026. Shaded bands mark months with no data.1001101201302023202420252026South Dakota120.5National117.8
South Dakota and the nation, Jan 2023 = 100Line chart, January 2023 to September 2026. South Dakota: 120.5 in September 2026. National (same jurisdictions each month): 117.8 in September 2026. Shaded bands mark months with no data.10011012013020232025South120.5National117.8
  • South Dakota
  • National (same jurisdictions each month)
  • Shaded: no data that month
View the data table
South Dakota and the nation, Jan 2023 = 100: values by month
MonthSouth DakotaNational (same jurisdictions each month)
Sep 2026120.5117.8
Aug 2026120.5117.8
Jul 2026120.2117.5
Jun 2026120.1117.4
May 2026119.8117.2
Apr 2026119.7116.9
Mar 2026119.1116.7
Feb 2026117.9116.3
Jan 2026112.2114.7
Dec 2025125.5115.9
Nov 2025125.5115.9
Oct 2025125.3115.7
Sep 2025125.1115.5
Aug 2025124.8115.3
Jul 2025124.3115
Jun 2025123.9114.8
May 2025123.6114.4
Apr 2025123.2114.2
Mar 2025122.9113.8
Feb 2025122.2113.4
Jan 2025119.3111.9
Dec 2024118.5112
Nov 2024118.3112
Oct 2024117.9111.7
Sep 2024117.7111.5
Aug 2024117.1111.2
Jul 2024116.7110.9
Jun 2024116.3110.7
May 2024115.9110.5
Apr 2024115.6110
Mar 2024115.2109.7
Feb 2024113.1109.3
Jan 2024112.4108.7
Dec 2023––
Nov 2023108105.9
Oct 2023107.7105.6
Sep 2023107.1105.2
Aug 2023106.6104.9
Jul 2023––
Jun 2023105.5104.1
May 2023105.1103.8
Apr 2023104.3103.4
Mar 2023103.6103
Feb 2023102.8102.2
Jan 2023100100

County file · Sep 2026. National line sums the jurisdictions that report in every month.

Individual plans

Individual plans leave out employer and union group coverage, so counts are smaller than in the county file.

Carrier share in South Dakota

Share of members whose contract has a carrier label, September 2026 against September 2025.

Contract file · Sep 2026
CMS contract file (SCC). All Medicare Advantage contracts, with employer and union group plans included. It still lists Connecticut and Alaska.

Medica leads with 58.9% of members who have a carrier label (contract file, September 2026).

Medica gained 17.7 points in 12 months; most of that change came in January 2026.

BCBS Michigan lost 4.4 points in 12 months; most of that change came in January 2026.

UnitedHealthcare and Humana together hold 11.4%, down 10.0 points from Sep 2025.

The market is more concentrated than a year earlier (direction only; the level depends on how carriers are grouped).

Carrier share, Sep 2025 to Sep 2026

Percent of members with a carrier label. Largest carriers.

Carrier share, Sep 2025 to Sep 2026Slope chart comparing Sep 2025 with Sep 2026. Medica: 41.2% to 58.9%; BCBS Michigan: 19.1% to 14.7%; UnitedHealthcare: 16.9% to 11.2%; Aetna/CVS: 10.6% to 8.2%; Sanford Health: 5.0% to 6.7%; Humana: 4.4% to 0.2%.Sep 2025Sep 2026Medica 41.2%58.9% MedicaBCBS Michigan 19.1%14.7% BCBS MichiganUnitedHealthcare 16.9%11.2% UnitedHealthcareAetna/CVS 10.6%8.2% Aetna/CVSSanford Health 5.0%6.7% Sanford HealthHumana 4.4%0.2% Humana
Carrier share, Sep 2025 to Sep 2026Slope chart comparing Sep 2025 with Sep 2026. Medica: 41.2% to 58.9%; BCBS Michigan: 19.1% to 14.7%; UnitedHealthcare: 16.9% to 11.2%; Aetna/CVS: 10.6% to 8.2%; Sanford Health: 5.0% to 6.7%; Humana: 4.4% to 0.2%.Sep 2025Sep 2026Medica 41.2%58.9%Blue Cross 19.1%14.7%UHC 16.9%11.2%Aetna 10.6%8.2%Sanford 5.0%6.7%Humana 4.4%0.2%
View the data table
Carrier share, Sep 2025 to Sep 2026: Sep 2025 and Sep 2026
NameSep 2025Sep 2026Change
Medica41.2%58.9%+17.7 pts
BCBS Michigan19.1%14.7%−4.4 pts
UnitedHealthcare16.9%11.2%−5.8 pts
Aetna/CVS10.6%8.2%−2.4 pts
Sanford Health5.0%6.7%+1.7 pts
Humana4.4%0.2%−4.2 pts

Contract file · Sep 2026. Employer group plans included.

Carrier share of Medicare Advantage members with a carrier label, South Dakota, September 2026
CarrierShare, Sep 2026Share, Sep 2025ChangeMembers
Medica58.9%41.2%+17.7 pts42,433
BCBS Michigan14.7%19.1%−4.4 pts10,601
UnitedHealthcare11.2%16.9%−5.8 pts8,039
Aetna/CVS8.2%10.6%−2.4 pts5,905
Sanford Health6.7%5.0%+1.7 pts4,804
Humana0.2%4.4%−4.2 pts150
Elevance/Anthem0.1%0.1%0.0 pts92
BCBS Minnesota0.0%0.0%0.0 pts12
HCSC/BCBS0.0%0.0%0.0 pts12
Kaiser0.0%0.0%0.0 pts11
All other carriers0.0%––0
HealthPartners–2.6%––

Insurer not assigned in CMS data: 0.0% of all members in Sep 2026, 0.0% in Sep 2025. Shares leave these members out. Contract IDs are renumbered each January, so this page follows carriers, not contracts. A contract that serves several states carries one carrier label, so a carrier can appear in a state where it is not a local plan. See the carrier view for the whole nation.

Biggest counties in South Dakota

Individual plan members and the 12-month change for each county, from county data.

Individual MA · Sep 2026
Individual Medicare Advantage plans (IND), from county data. Employer and union group plans are left out, so counts are smaller than in the other two files.
Biggest counties in South Dakota by individual Medicare Advantage members, September 2026
CountyMembers12-month changeLeading carrierLeader's share
Minnehaha16,809−0.5%Medica46.2%
Pennington8,441−13.1%Medica65.5%
Lincoln5,379+4.3%Medica53.5%
Codington3,145−10.6%Medica92.5%
Lawrence2,784−8.5%Medica61.5%
Brookings2,619+1.8%BCBS Michigan43.5%
Brown2,453+6.8%Medica92.0%
Yankton2,073+3.0%Medica71.0%
Meade2,000−11.6%Medica67.3%
Davison1,785−0.7%BCBS Michigan43.6%

1 of 66 counties have no individual plan row. Those read "not reported", not zero. Browse all counties.

Common questions

How many people have Medicare Advantage in South Dakota?

South Dakota had 72,849 members in September 2026, by the CMS county file (employer group plans included). Individual plans, which leave out employer group coverage, had 68,204 members in September 2026.

Is Medicare Advantage growing in South Dakota?

Enrollment is down 3.6% from Sep 2025 to Sep 2026, while the nation grew 2.0%. Among individual plans, which leave out employer group coverage, enrollment is down 2.6% in the 12 months to September 2026.

Which carrier has the most Medicare Advantage members in South Dakota?

Medica leads with 58.9% of members who have a carrier label (contract file, September 2026). UnitedHealthcare and Humana together hold 11.4%, down 10.0 points from Sep 2025. Shares leave out members whose contract has no carrier label: 0.0% of members.

Cite and download

Cite this page

Senior Deal Club Standards Desk. Medicare Advantage Enrollment in South Dakota, data as of September 2026. Source: CMS public enrollment files. https://www.seniordealclub.com/medicare-advantage/enrollment/states/south-dakota

Download South Dakota CSV

Data: CMS public enrollment files, in a monthly snapshot processed by TapQuality. Senior Deal Club is not affiliated with Medicare or any government agency.

These pages are educational. They are not plan advice. How the numbers are built · Editorial policy