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Medicare Advantage Enrollment Tracker · Missouri

Medicare Advantage Enrollment in Missouri

Missouri had 751,675 Medicare Advantage members in September 2026, by the CMS county file, which includes employer group plans. That is up 2.5% from Sep 2025, close to the national 2.0%. Missouri ranks 16th by members and holds 2.1% of the national total.

UnitedHealthcare leads with 44.8% of members who have a carrier label (contract file, September 2026). Among individual plans, which leave out employer group coverage, enrollment is up 3.0% 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.

Missouri at a glance

Medicare Advantage members

751,675

Missouri members by month: from 645K in Jan 2023 to 752K in Sep 2026

County file · Sep 2026. Includes employer group plans. Rank: 16.

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

+2.5%

up 2.5 percent vs Sep 2025

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

Share of national total

2.1%

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

Individual plan members

643,735

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

UnitedHealthcare

44.8% of members with a carrier label. Contract file · Sep 2026.

Missouri members by month

Medicare Advantage members in Missouri

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 MissouriLine chart, January 2023 to September 2026. Missouri: 752K in September 2026. Shaded bands mark months with no data.600K650K700K750K800K2023202420252026Missouri752K
Medicare Advantage members in MissouriLine chart, January 2023 to September 2026. Missouri: 752K in September 2026. Shaded bands mark months with no data.600K650K700K750K800K20232025Missouri752K
  • Missouri
  • Shaded: no data that month
View the data table
Medicare Advantage members in Missouri: values by month
MonthMissouri
Sep 2026752K
Aug 2026751K
Jul 2026750K
Jun 2026749K
May 2026748K
Apr 2026747K
Mar 2026746K
Feb 2026744K
Jan 2026737K
Dec 2025735K
Nov 2025735K
Oct 2025735K
Sep 2025734K
Aug 2025733K
Jul 2025731K
Jun 2025730K
May 2025729K
Apr 2025727K
Mar 2025726K
Feb 2025724K
Jan 2025715K
Dec 2024713K
Nov 2024713K
Oct 2024712K
Sep 2024711K
Aug 2024709K
Jul 2024708K
Jun 2024707K
May 2024706K
Apr 2024703K
Mar 2024701K
Feb 2024700K
Jan 2024694K
Dec 2023–
Nov 2023675K
Oct 2023673K
Sep 2023671K
Aug 2023669K
Jul 2023–
Jun 2023665K
May 2023663K
Apr 2023660K
Mar 2023659K
Feb 2023656K
Jan 2023645K

County file · Sep 2026. Employer group plans included.

Missouri 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.
Missouri and the nation, Jan 2023 = 100Line chart, January 2023 to September 2026. Missouri: 116.5 in September 2026. National (same jurisdictions each month): 117.8 in September 2026. Shaded bands mark months with no data.1001051101151202023202420252026National117.8Missouri116.5
Missouri and the nation, Jan 2023 = 100Line chart, January 2023 to September 2026. Missouri: 116.5 in September 2026. National (same jurisdictions each month): 117.8 in September 2026. Shaded bands mark months with no data.10010511011512020232025National117.8Missouri116.5
  • Missouri
  • National (same jurisdictions each month)
  • Shaded: no data that month
View the data table
Missouri and the nation, Jan 2023 = 100: values by month
MonthMissouriNational (same jurisdictions each month)
Sep 2026116.5117.8
Aug 2026116.4117.8
Jul 2026116.2117.5
Jun 2026116.1117.4
May 2026115.9117.2
Apr 2026115.7116.9
Mar 2026115.6116.7
Feb 2026115.3116.3
Jan 2026114.2114.7
Dec 2025113.9115.9
Nov 2025113.9115.9
Oct 2025113.9115.7
Sep 2025113.7115.5
Aug 2025113.6115.3
Jul 2025113.3115
Jun 2025113.1114.8
May 2025113114.4
Apr 2025112.7114.2
Mar 2025112.6113.8
Feb 2025112.2113.4
Jan 2025110.8111.9
Dec 2024110.5112
Nov 2024110.5112
Oct 2024110.3111.7
Sep 2024110.2111.5
Aug 2024109.9111.2
Jul 2024109.7110.9
Jun 2024109.5110.7
May 2024109.4110.5
Apr 2024108.9110
Mar 2024108.7109.7
Feb 2024108.4109.3
Jan 2024107.6108.7
Dec 2023––
Nov 2023104.6105.9
Oct 2023104.3105.6
Sep 2023104105.2
Aug 2023103.7104.9
Jul 2023––
Jun 2023103104.1
May 2023102.7103.8
Apr 2023102.4103.4
Mar 2023102.1103
Feb 2023101.7102.2
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 Missouri

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.

UnitedHealthcare leads with 44.8% of members who have a carrier label (contract file, September 2026).

UnitedHealthcare lost 5.0 points in 12 months; most of that change came in January 2026.

Humana gained 9.4 points in 12 months; most of that change came in January 2026.

UnitedHealthcare and Humana together hold 67.1%, up 4.4 points from Sep 2025.

The market is less 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. UnitedHealthcare: 49.8% to 44.8%; Humana: 13.0% to 22.3%; Aetna/CVS: 19.2% to 16.2%; Lumeris Group Holdings Corporation: 5.8% to 6.1%; Elevance/Anthem: 8.4% to 3.6%; Devoted Health: 0.6% to 3.6%.Sep 2025Sep 2026UnitedHealthcare 49.8%44.8% UnitedHealthcareHumana 13.0%22.3% HumanaAetna/CVS 19.2%16.2% Aetna/CVSLumeris 5.8%6.1% LumerisElevance/Anthem 8.4%3.6% Elevance/AnthemDevoted Health 0.6%3.6% Devoted Health
Carrier share, Sep 2025 to Sep 2026Slope chart comparing Sep 2025 with Sep 2026. UnitedHealthcare: 49.8% to 44.8%; Humana: 13.0% to 22.3%; Aetna/CVS: 19.2% to 16.2%; Lumeris Group Holdings Corporation: 5.8% to 6.1%; Elevance/Anthem: 8.4% to 3.6%; Devoted Health: 0.6% to 3.6%.Sep 2025Sep 2026UHC 49.8%44.8%Humana 13.0%22.3%Aetna 19.2%16.2%Lumeris 5.8%6.1%Elevance 8.4%3.6%Devoted 0.6%3.6%
View the data table
Carrier share, Sep 2025 to Sep 2026: Sep 2025 and Sep 2026
NameSep 2025Sep 2026Change
UnitedHealthcare49.8%44.8%−5.0 pts
Humana13.0%22.3%+9.4 pts
Aetna/CVS19.2%16.2%−3.0 pts
Lumeris Group Holdings Corporation5.8%6.1%+0.2 pts
Elevance/Anthem8.4%3.6%−4.8 pts
Devoted Health0.6%3.6%+3.0 pts

Contract file · Sep 2026. Employer group plans included.

Carrier share of Medicare Advantage members with a carrier label, Missouri, September 2026
CarrierShare, Sep 2026Share, Sep 2025ChangeMembers
UnitedHealthcare44.8%49.8%−5.0 pts335,010
Humana22.3%13.0%+9.4 pts166,984
Aetna/CVS16.2%19.2%−3.0 pts121,230
Lumeris Group Holdings Corporation6.1%5.8%+0.2 pts45,333
Elevance/Anthem3.6%8.4%−4.8 pts26,846
Devoted Health3.6%0.6%+3.0 pts26,779
BCBS Michigan1.2%1.3%−0.1 pts9,056
Centene/Wellcare0.9%0.9%+0.1 pts7,065
CoxHealth0.6%0.5%+0.1 pts4,348
HCSC/BCBS0.4%0.3%+0.2 pts3,162
All other carriers0.3%––2,256

Insurer not assigned in CMS data: 0.1% of all members in Sep 2026, 0.3% 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 Missouri

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 Missouri by individual Medicare Advantage members, September 2026
CountyMembers12-month changeLeading carrierLeader's share
St. Louis114,648+2.6%UnitedHealthcare39.7%
Jackson68,253+2.9%Humana39.8%
St. Charles44,718+4.0%UnitedHealthcare42.7%
Greene37,904+2.5%Humana25.5%
St. Louis City29,399+0.7%UnitedHealthcare38.9%
Jefferson29,383+2.9%UnitedHealthcare34.6%
Clay19,461+4.6%Humana62.8%
Franklin17,480+4.0%UnitedHealthcare53.6%
Jasper12,758+3.3%Humana31.7%
Christian11,406+4.3%Humana26.7%

Browse all counties.

Common questions

How many people have Medicare Advantage in Missouri?

Missouri had 751,675 members in September 2026, by the CMS county file (employer group plans included). Individual plans, which leave out employer group coverage, had 643,735 members in September 2026.

Is Medicare Advantage growing in Missouri?

Enrollment is up 2.5% from Sep 2025 to Sep 2026, close to the national 2.0%. Among individual plans, which leave out employer group coverage, enrollment is up 3.0% in the 12 months to September 2026.

Which carrier has the most Medicare Advantage members in Missouri?

UnitedHealthcare leads with 44.8% of members who have a carrier label (contract file, September 2026). UnitedHealthcare and Humana together hold 67.1%, up 4.4 points from Sep 2025. Shares leave out members whose contract has no carrier label: 0.1% of members.

Cite and download

Cite this page

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

Download Missouri 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