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Medicare Advantage Enrollment Tracker · Iowa

Medicare Advantage Enrollment in Iowa

Iowa had 267,845 Medicare Advantage members in September 2026, by the CMS county file, which includes employer group plans. That is down 0.2% from Sep 2025, while the nation grew 2.0%. Iowa ranks 34th by members and holds 0.7% of the national total.

Aetna/CVS leads with 30.6% of members who have a carrier label (contract file, September 2026). UnitedHealthcare led a year earlier. Among individual plans, which leave out employer group coverage, enrollment is up 1.4% 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.

Iowa at a glance

Medicare Advantage members

267,845

Iowa members by month: from 223K in Jan 2023 to 268K in Sep 2026

County file · Sep 2026. Includes employer group plans. Rank: 34.

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

-0.2%

down 0.2 percent vs Sep 2025

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

Share of national total

0.7%

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

Individual plan members

240,688

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

Aetna/CVS

30.6% of members with a carrier label. Contract file · Sep 2026.

Iowa members by month

Medicare Advantage members in Iowa

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 IowaLine chart, January 2023 to September 2026. Iowa: 268K in September 2026. Shaded bands mark months with no data.220K240K260K280K2023202420252026Iowa268K
Medicare Advantage members in IowaLine chart, January 2023 to September 2026. Iowa: 268K in September 2026. Shaded bands mark months with no data.220K240K260K280K20232025Iowa268K
  • Iowa
  • Shaded: no data that month
View the data table
Medicare Advantage members in Iowa: values by month
MonthIowa
Sep 2026268K
Aug 2026268K
Jul 2026268K
Jun 2026267K
May 2026267K
Apr 2026267K
Mar 2026267K
Feb 2026266K
Jan 2026261K
Dec 2025269K
Nov 2025269K
Oct 2025269K
Sep 2025268K
Aug 2025268K
Jul 2025267K
Jun 2025267K
May 2025266K
Apr 2025266K
Mar 2025265K
Feb 2025264K
Jan 2025260K
Dec 2024257K
Nov 2024257K
Oct 2024257K
Sep 2024256K
Aug 2024256K
Jul 2024255K
Jun 2024255K
May 2024254K
Apr 2024253K
Mar 2024253K
Feb 2024252K
Jan 2024251K
Dec 2023–
Nov 2023239K
Oct 2023239K
Sep 2023238K
Aug 2023237K
Jul 2023–
Jun 2023235K
May 2023233K
Apr 2023232K
Mar 2023231K
Feb 2023229K
Jan 2023223K

County file · Sep 2026. Employer group plans included.

Iowa 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.
Iowa and the nation, Jan 2023 = 100Line chart, January 2023 to September 2026. Iowa: 120 in September 2026. National (same jurisdictions each month): 117.8 in September 2026. Shaded bands mark months with no data.1001101201302023202420252026Iowa120National117.8
Iowa and the nation, Jan 2023 = 100Line chart, January 2023 to September 2026. Iowa: 120 in September 2026. National (same jurisdictions each month): 117.8 in September 2026. Shaded bands mark months with no data.10011012013020232025Iowa120National117.8
  • Iowa
  • National (same jurisdictions each month)
  • Shaded: no data that month
View the data table
Iowa and the nation, Jan 2023 = 100: values by month
MonthIowaNational (same jurisdictions each month)
Sep 2026120117.8
Aug 2026119.9117.8
Jul 2026119.8117.5
Jun 2026119.7117.4
May 2026119.7117.2
Apr 2026119.7116.9
Mar 2026119.4116.7
Feb 2026119116.3
Jan 2026116.9114.7
Dec 2025120.4115.9
Nov 2025120.6115.9
Oct 2025120.4115.7
Sep 2025120.2115.5
Aug 2025120.1115.3
Jul 2025119.7115
Jun 2025119.5114.8
May 2025119.1114.4
Apr 2025119114.2
Mar 2025118.8113.8
Feb 2025118.3113.4
Jan 2025116.3111.9
Dec 2024115.1112
Nov 2024115.1112
Oct 2024115111.7
Sep 2024114.8111.5
Aug 2024114.5111.2
Jul 2024114.3110.9
Jun 2024114.1110.7
May 2024113.7110.5
Apr 2024113.3110
Mar 2024113.2109.7
Feb 2024112.7109.3
Jan 2024112.3108.7
Dec 2023––
Nov 2023107.2105.9
Oct 2023106.9105.6
Sep 2023106.5105.2
Aug 2023106104.9
Jul 2023––
Jun 2023105.1104.1
May 2023104.5103.8
Apr 2023103.8103.4
Mar 2023103.3103
Feb 2023102.7102.2
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 Iowa

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.

Aetna/CVS leads with 30.6% of members who have a carrier label (contract file, September 2026). UnitedHealthcare led a year earlier.

Aetna/CVS gained 5.6 points in 12 months; most of that change came in January 2026.

UnitedHealthcare lost 13.9 points in 12 months; most of that change came in January 2026.

UnitedHealthcare and Humana together hold 40.5%, down 10.9 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. Aetna/CVS: 25.0% to 30.6%; UnitedHealthcare: 40.7% to 26.8%; Humana: 10.7% to 13.7%; BCBS Michigan: 12.4% to 12.6%; Medical Associates Clinic, P.C.: 5.1% to 5.2%; Centene/Wellcare: 1.5% to 4.9%.Sep 2025Sep 2026Aetna/CVS 25.0%30.6% Aetna/CVSUnitedHealthcare 40.7%26.8% UnitedHealthcareHumana 10.7%13.7% HumanaBCBS Michigan 12.4%12.6% BCBS MichiganMedical 5.1%5.2% MedicalCentene/Wellcare 1.5%4.9% Centene/Wellcare
Carrier share, Sep 2025 to Sep 2026Slope chart comparing Sep 2025 with Sep 2026. Aetna/CVS: 25.0% to 30.6%; UnitedHealthcare: 40.7% to 26.8%; Humana: 10.7% to 13.7%; BCBS Michigan: 12.4% to 12.6%; Medical Associates Clinic, P.C.: 5.1% to 5.2%; Centene/Wellcare: 1.5% to 4.9%.Sep 2025Sep 2026Aetna 25.0%30.6%UHC 40.7%26.8%Humana 10.7%13.7%Blue Cross 12.4%12.6%Medical 5.1%5.2%Centene 1.5%4.9%
View the data table
Carrier share, Sep 2025 to Sep 2026: Sep 2025 and Sep 2026
NameSep 2025Sep 2026Change
Aetna/CVS25.0%30.6%+5.6 pts
UnitedHealthcare40.7%26.8%−13.9 pts
Humana10.7%13.7%+3.0 pts
BCBS Michigan12.4%12.6%+0.2 pts
Medical Associates Clinic, P.C.5.1%5.2%+0.1 pts
Centene/Wellcare1.5%4.9%+3.4 pts

Contract file · Sep 2026. Employer group plans included.

Carrier share of Medicare Advantage members with a carrier label, Iowa, September 2026
CarrierShare, Sep 2026Share, Sep 2025ChangeMembers
Aetna/CVS30.6%25.0%+5.6 pts81,024
UnitedHealthcare26.8%40.7%−13.9 pts71,005
Humana13.7%10.7%+3.0 pts36,141
BCBS Michigan12.6%12.4%+0.2 pts33,293
Medical Associates Clinic, P.C.5.2%5.1%+0.1 pts13,851
Centene/Wellcare4.9%1.5%+3.4 pts12,974
Trinity Health Corporation3.1%1.4%+1.7 pts8,176
Elevance/Anthem1.6%2.3%−0.8 pts4,114
Mitchell Family Office0.5%0.4%+0.1 pts1,426
All other carriers0.4%––1,007
Molina0.3%––829
Medica0.3%0.2%+0.1 pts801

Insurer not assigned in CMS data: 0.3% of all members in Sep 2026, 1.3% 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 Iowa

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 Iowa by individual Medicare Advantage members, September 2026
CountyMembers12-month changeLeading carrierLeader's share
Polk37,850+3.4%UnitedHealthcare36.0%
Linn22,750+2.0%Aetna/CVS42.3%
Scott15,743+2.2%Aetna/CVS47.3%
Dubuque12,233+3.4%Medical Associates Clinic, P.C.84.2%
Black Hawk10,652−0.5%Aetna/CVS33.2%
Pottawattamie9,408+2.1%UnitedHealthcare41.8%
Woodbury8,984−0.1%Aetna/CVS53.4%
Johnson7,789+5.9%Aetna/CVS37.9%
Dallas5,885+4.1%Aetna/CVS37.1%
Clinton4,603+1.7%Aetna/CVS39.1%

Browse all counties.

Common questions

How many people have Medicare Advantage in Iowa?

Iowa had 267,845 members in September 2026, by the CMS county file (employer group plans included). Individual plans, which leave out employer group coverage, had 240,688 members in September 2026.

Is Medicare Advantage growing in Iowa?

Enrollment is down 0.2% from Sep 2025 to Sep 2026, while the nation grew 2.0%. Among individual plans, which leave out employer group coverage, enrollment is up 1.4% in the 12 months to September 2026.

Which carrier has the most Medicare Advantage members in Iowa?

Aetna/CVS leads with 30.6% of members who have a carrier label (contract file, September 2026). UnitedHealthcare led a year earlier. UnitedHealthcare and Humana together hold 40.5%, down 10.9 points from Sep 2025. Shares leave out members whose contract has no carrier label: 0.3% of members.

Cite and download

Cite this page

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

Download Iowa 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