Free tool · public CMS data
California Medicare Advantage market share
In September 2026, 3,710,031 California Medicare beneficiaries were enrolled in a Medicare Advantage plan across 127 parent carriers and 58 counties, led by Kaiser Foundation Health Plan, Inc. with 41.1% of counted enrollment.
Data month
September 2026
Advantage enrollees
3,710,031
+2.1% vs September 2025
Parent carriers
127
Advantage penetration
50.7%
CMS Medicare Monthly Enrollment, 2024
Carriers in California
CMS Monthly Enrollment by Contract/Plan/State/County (CPSC) · September 2026
| # | Parent organisation | Enrollees | Share | Counties | vs September 2025 |
|---|---|---|---|---|---|
| 1 | Kaiser Foundation Health Plan, Inc. | 1,525,598 | 41.1% | 58 | +3.9% |
| 2 | SCAN Group | 432,687 | 11.7% | 52 | +43.2% |
| 3 | UnitedHealth Group, Inc. | 379,612 | 10.2% | 58 | -21.0% |
| 4 | Elevance Health, Inc. | 282,622 | 7.6% | 58 | -10.7% |
| 5 | Alignment Healthcare USA, LLC | 236,314 | 6.4% | 58 | +23.2% |
| 6 | Humana Inc. | 145,886 | 3.9% | 58 | +7.4% |
| 7 | California Physicians' Service | 116,737 | 3.1% | 58 | -9.6% |
| 8 | CVS Health Corporation | 99,246 | 2.7% | 58 | -27.3% |
| 9 | Centene Corporation | 82,085 | 2.2% | 51 | -27.0% |
| 10 | Molina Healthcare, Inc. | 63,208 | 1.7% | 38 | -40.8% |
| 11 | Astiva Health Holdings Incorporated | 53,162 | 1.4% | 26 | +42.0% |
| 12 | Clever Care Health Plan, Inc. | 52,613 | 1.4% | 11 | +81.0% |
| 13 | Imperial Health Plan of California | 52,590 | 1.4% | 56 | +124.0% |
| 14 | INLAND EMPIRE HEALTH PLAN | 38,297 | 1.0% | 10 | +0.8% |
| 15 | Local Initiative Health Authority for LA County | 30,502 | 0.8% | 22 | +5.1% |
| 16 | Sharp Healthcare | 19,745 | 0.5% | 15 | +14.6% |
| 17 | Orange County Health Authority | 19,098 | 0.5% | 7 | +6.0% |
| 18 | SANTA CLARA COUNTY HEALTH AUTHORITY | 11,830 | 0.3% | 33 | +4.0% |
| 19 | The Regents of the University of California | 11,812 | 0.3% | 16 | +66.3% |
| 20 | Community Health Group | 10,709 | 0.3% | 16 | +16.4% |
| 21 | Champion Health Plans-USA, LLC. | 9,433 | 0.3% | 21 | +4616.5% |
| 22 | Health Plan of San Mateo | 8,464 | 0.2% | 25 | +1.0% |
| 23 | Montage Health | 8,335 | 0.2% | 14 | +4.4% |
| 24 | Chinese Hospital Association | 5,729 | 0.2% | 7 | -1.8% |
| 25 | Providence St Joseph Health | 3,976 | 0.1% | 10 | -53.2% |
| 26 | Kern Health Systems (KHS) | 1,343 | 0.0% | 4 | — |
| 27 | SAN FRANCISCO HEALTH AUTHORITY | 1,225 | 0.0% | 5 | — |
| 28 | SANTA CRUZ MONTEREY MERCED SAN BENITO MARIPOSA MAN | 1,091 | 0.0% | 7 | — |
| 29 | Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 1,076 | 0.0% | 58 | -3.2% |
| 30 | SANTA BARBARA SAN LUIS OBISPO REGIONAL HEALTH AUTH | 771 | 0.0% | 4 | — |
| 31 | Ventura County Medi-Cal Managed Care Commission | 723 | 0.0% | 5 | — |
| 32 | Curana Health Holdings, LLC | 672 | 0.0% | 11 | +56.3% |
| 33 | AIDS Healthcare Foundation | 587 | 0.0% | 4 | -0.5% |
| 34 | Contra Costa Health Services | 578 | 0.0% | 12 | — |
| 35 | IMPERIAL COUNTY LOCAL HEALTH AUTHORITY | 486 | 0.0% | 1 | — |
| 36 | Health Care Service Corporation | 372 | 0.0% | 58 | +7.5% |
| 37 | SAN JOAQUIN COUNTY HEALTH COMMISSION | 346 | 0.0% | 7 | — |
| 38 | Alameda Alliance for Health | 293 | 0.0% | 4 | — |
| 39 | Highmark Health | 116 | 0.0% | 58 | +10.5% |
| 40 | Cambia Health Solutions, Inc. | 41 | 0.0% | 58 | -14.6% |
| 41 | Elite Health Systems, Inc. | 21 | 0.0% | 3 | — |
| 42 | AllCare Health, Inc. | 0 | 0.0% | 2 | — |
| 43 | Allina Health and Aetna Insurance Holding Company | 0 | 0.0% | 58 | — |
| 44 | AlohaCare | 0 | 0.0% | 4 | — |
| 45 | Athena Healthcare Holdings, LLC | 0 | 0.0% | 6 | — |
| 46 | ATRIO Health Plans | 0 | 0.0% | 16 | — |
| 47 | Aultman Health Foundation | 0 | 0.0% | 58 | — |
| 48 | Aware Integrated, Inc. | 0 | 0.0% | 58 | — |
| 49 | Banner Health | 0 | 0.0% | 3 | — |
| 50 | BayCare Health System, Inc. | 0 | 0.0% | 4 | — |
| 51 | Baylor Scott & White Health | 0 | 0.0% | 1 | — |
| 52 | Baystate Health, Inc. | 0 | 0.0% | 58 | — |
| 53 | Blue Cross & Blue Shield of Rhode Island | 0 | 0.0% | 58 | — |
| 54 | Blue Cross and Blue Shield of Massachusetts, Inc. | 0 | 0.0% | 58 | — |
| 55 | Blue Cross Blue Shield of Arizona | 0 | 0.0% | 13 | — |
| 56 | Blue Cross Blue Shield of Kansas | 0 | 0.0% | 58 | — |
| 57 | Blue Cross Blue Shield of Nebraska | 0 | 0.0% | 58 | — |
| 58 | BlueCross BlueShield of Alabama | 0 | 0.0% | 58 | — |
| 59 | BlueCross BlueShield of South Carolina (BCBSSC) | 0 | 0.0% | 58 | — |
| 60 | BlueCross BlueShield of Tennessee | 0 | 0.0% | 58 | — |
| 61 | BMC Health System, Inc. | 0 | 0.0% | 1 | — |
| 62 | CAPITAL BLUE CROSS | 0 | 0.0% | 58 | — |
| 63 | CareFirst, Inc. | 0 | 0.0% | 58 | — |
| 64 | CareOregon, Inc. | 0 | 0.0% | 5 | — |
| 65 | CareSource | 0 | 0.0% | 19 | — |
| 66 | Clover Health Holdings, Inc. | 0 | 0.0% | 3 | — |
| 67 | Community Health Plan of Washington | 0 | 0.0% | 6 | — |
| 68 | Corewell Health | 0 | 0.0% | 58 | — |
| 69 | CuraCor Solutions Corp. | 0 | 0.0% | 58 | — |
| 70 | Devoted Health, Inc. | 0 | 0.0% | 15 | — |
| 71 | DLP Marquette Health Plan, LLC | 0 | 0.0% | 1 | — |
| 72 | DOCTORS HEALTHCARE PLANS, INC. | 0 | 0.0% | 3 | — |
| 73 | El Paso County Hospital District | 0 | 0.0% | 1 | — |
| 74 | Elderplan, Inc. | 0 | 0.0% | 2 | — |
| 75 | EmblemHealth, Inc. | 0 | 0.0% | 58 | — |
| 76 | Eternal Health of Delaware, Inc. | 0 | 0.0% | 1 | — |
| 77 | Fallon Community Health Plan, Inc. | 0 | 0.0% | 58 | — |
| 78 | Fenyx Health Holdings, Inc. | 0 | 0.0% | 58 | — |
| 79 | First Sacramento Capital Funding LLC | 0 | 0.0% | 1 | — |
| 80 | Gemstone Holdings, Inc. | 0 | 0.0% | 6 | — |
| 81 | General Catalyst Group Management Holdings LP | 0 | 0.0% | 58 | — |
| 82 | Gold Kidney Health Plan | 0 | 0.0% | 6 | — |
| 83 | Guidewell Mutual Holding Corporation | 0 | 0.0% | 58 | — |
| 84 | Hawaii Medical Service Association | 0 | 0.0% | 58 | — |
| 85 | Healthfirst, Inc. | 0 | 0.0% | 58 | — |
| 86 | HealthPartners, Inc. | 0 | 0.0% | 58 | — |
| 87 | Henry Ford Health System | 0 | 0.0% | 58 | — |
| 88 | Horizon Mutual Holdings, Inc | 0 | 0.0% | 58 | — |
| 89 | Independence Health Group, Inc. | 0 | 0.0% | 58 | — |
| 90 | Independent Health Association, Inc. | 0 | 0.0% | 58 | — |
| 91 | Intermountain Health Care, Inc. | 0 | 0.0% | 17 | — |
| 92 | Johns Hopkins Healthcare LLC | 0 | 0.0% | 3 | — |
| 93 | LifeBridge Health, Inc. | 0 | 0.0% | 1 | — |
| 94 | Lifetime Healthcare, Inc. | 0 | 0.0% | 58 | — |
| 95 | Longevity Health Founders, LLC | 0 | 0.0% | 5 | — |
| 96 | Louisiana Health Service & Indemnity Company | 0 | 0.0% | 58 | — |
| 97 | Lumeris Group Holdings Corporation | 0 | 0.0% | 4 | — |
| 98 | Marquis Companies I, Inc. | 0 | 0.0% | 1 | — |
| 99 | Martin's Point Health Care, Inc. | 0 | 0.0% | 58 | — |
| 100 | Mass General Brigham Incorporated | 0 | 0.0% | 6 | — |
| 101 | Medica Holding Company | 0 | 0.0% | 58 | — |
| 102 | MEDICAL MUTUAL OF OHIO | 0 | 0.0% | 58 | — |
| 103 | Memorial Hermann Health System | 0 | 0.0% | 4 | — |
| 104 | Mercy Care | 0 | 0.0% | 3 | — |
| 105 | MHH Healthcare, L.P. | 0 | 0.0% | 2 | — |
| 106 | MVP Health Care, Inc. | 0 | 0.0% | 58 | — |
| 107 | Network Health, Inc. | 0 | 0.0% | 58 | — |
| 108 | PacificSource | 0 | 0.0% | 17 | — |
| 109 | Perennial Consortium, LLC | 0 | 0.0% | 2 | — |
| 110 | Point32Health, Inc. | 0 | 0.0% | 6 | — |
| 111 | Presbyterian Healthcare Services | 0 | 0.0% | 6 | — |
| 112 | Rifkin Managed Care Holding, LLC | 0 | 0.0% | 1 | — |
| 113 | Sanford Health | 0 | 0.0% | 6 | — |
| 114 | Sentara Health Care (SHC) | 0 | 0.0% | 1 | — |
| 115 | St Francis Health System & St John Health System | 0 | 0.0% | 1 | — |
| 116 | The Health Plan of West Virginia, Inc. | 0 | 0.0% | 58 | — |
| 117 | Thomas Jefferson University | 0 | 0.0% | 3 | — |
| 118 | Trinity Health Corporation | 0 | 0.0% | 19 | — |
| 119 | Ultimate Healthcare Holdings, LLC | 0 | 0.0% | 1 | — |
| 120 | UNICO Services, Inc. | 0 | 0.0% | 1 | — |
| 121 | Universal Health Services, Inc. | 0 | 0.0% | 42 | — |
| 122 | University of Wisconsin Hospitals and Clincs Autho | 0 | 0.0% | 1 | — |
| 123 | UPMC Health System | 0 | 0.0% | 58 | — |
| 124 | USAble Mutual Insurance Company | 0 | 0.0% | 58 | — |
| 125 | Verda Healthcare, Inc. | 0 | 0.0% | 2 | — |
| 126 | Visiting Nurse Service of New York | 0 | 0.0% | 3 | — |
| 127 | Zing Health Consolidator, Inc | 0 | 0.0% | 1 | — |
County view
Leading carrier and Advantage enrollment in each California county. Penetration is from CMS Medicare Monthly Enrollment, 2024.
| County | Advantage enrollees | Leading carrier | Leader share | Carriers | Penetration |
|---|---|---|---|---|---|
| Los Angeles | 977,434 | Kaiser Foundation Health Plan, Inc. | 35.0% | 100 | 55.8% |
| Orange | 339,530 | Kaiser Foundation Health Plan, Inc. | 25.7% | 77 | 55.2% |
| San Diego | 332,158 | Kaiser Foundation Health Plan, Inc. | 34.1% | 85 | 52.9% |
| Riverside | 286,516 | Kaiser Foundation Health Plan, Inc. | 31.6% | 87 | 62.6% |
| San Bernardino | 236,216 | Kaiser Foundation Health Plan, Inc. | 35.1% | 75 | 66.0% |
| Sacramento | 184,911 | Kaiser Foundation Health Plan, Inc. | 59.2% | 78 | 59.3% |
| Santa Clara | 158,725 | Kaiser Foundation Health Plan, Inc. | 55.1% | 83 | 49.8% |
| Alameda | 146,086 | Kaiser Foundation Health Plan, Inc. | 74.1% | 76 | 51.5% |
| Contra Costa | 119,350 | Kaiser Foundation Health Plan, Inc. | 76.9% | 68 | 52.8% |
| San Francisco | 81,300 | Kaiser Foundation Health Plan, Inc. | 45.1% | 67 | 49.4% |
| Fresno | 77,598 | Kaiser Foundation Health Plan, Inc. | 29.6% | 61 | 46.8% |
| San Mateo | 73,249 | Kaiser Foundation Health Plan, Inc. | 58.6% | 67 | 50.5% |
| Ventura | 72,698 | Kaiser Foundation Health Plan, Inc. | 41.4% | 75 | 41.6% |
| San Joaquin | 70,837 | Kaiser Foundation Health Plan, Inc. | 49.0% | 68 | 52.6% |
| Sonoma | 65,598 | Kaiser Foundation Health Plan, Inc. | 78.9% | 65 | 53.9% |
| Kern | 63,997 | Kaiser Foundation Health Plan, Inc. | 32.6% | 69 | 46.9% |
| Placer | 58,229 | Kaiser Foundation Health Plan, Inc. | 61.4% | 58 | 56.1% |
| Stanislaus | 56,076 | Alignment Healthcare USA, LLC | 32.7% | 65 | 56.1% |
| Solano | 51,775 | Kaiser Foundation Health Plan, Inc. | 85.3% | 59 | 55.1% |
| Marin | 29,229 | Kaiser Foundation Health Plan, Inc. | 81.2% | 65 | 46.1% |
| Tulare | 26,275 | Humana Inc. | 33.4% | 63 | 35.2% |
| El Dorado | 21,690 | Kaiser Foundation Health Plan, Inc. | 63.4% | 58 | 44.1% |
| Yolo | 19,050 | Kaiser Foundation Health Plan, Inc. | 43.2% | 54 | 51.8% |
| San Luis Obispo | 17,542 | Alignment Healthcare USA, LLC | 32.3% | 66 | 24.3% |
| Santa Barbara | 17,329 | UnitedHealth Group, Inc. | 44.7% | 64 | 20.3% |
| Santa Cruz | 15,027 | Kaiser Foundation Health Plan, Inc. | 39.1% | 64 | 25.8% |
| Napa | 14,661 | Kaiser Foundation Health Plan, Inc. | 83.5% | 55 | 46.8% |
| Imperial | 13,911 | Champion Health Plans-USA, LLC. | 28.8% | 65 | 36.3% |
| Madera | 13,575 | Kaiser Foundation Health Plan, Inc. | 45.8% | 55 | 47.6% |
| Monterey | 12,032 | Montage Health | 68.8% | 59 | 15.4% |
| Merced | 11,777 | Imperial Health Plan of California | 39.0% | 58 | 28.1% |
| Kings | 7,428 | Elevance Health, Inc. | 26.4% | 57 | 35.4% |
| Nevada | 5,599 | UnitedHealth Group, Inc. | 66.5% | 56 | 22.9% |
| Butte | 5,345 | Elevance Health, Inc. | 35.0% | 57 | 16.8% |
| Shasta | 3,481 | Elevance Health, Inc. | 36.3% | 59 | 13.9% |
| Amador | 3,462 | Kaiser Foundation Health Plan, Inc. | 46.6% | 52 | 32.9% |
| Yuba | 2,767 | Kaiser Foundation Health Plan, Inc. | 49.0% | 54 | 25.2% |
| Mendocino | 2,490 | UnitedHealth Group, Inc. | 73.2% | 59 | 16.0% |
| Humboldt | 2,164 | Imperial Health Plan of California | 39.6% | 58 | 10.2% |
| Calaveras | 1,825 | Humana Inc. | 41.9% | 53 | 18.4% |
| Lake | 1,725 | UnitedHealth Group, Inc. | 73.9% | 57 | 21.3% |
| San Benito | 1,542 | Imperial Health Plan of California | 64.1% | 56 | 20.9% |
| Tuolumne | 1,514 | Elevance Health, Inc. | 28.5% | 55 | 14.0% |
| Sutter | 1,390 | Elevance Health, Inc. | 48.1% | 53 | 18.0% |
| Tehama | 1,332 | Elevance Health, Inc. | 50.3% | 53 | 18.4% |
| Mariposa | 627 | Humana Inc. | 35.7% | 52 | 16.2% |
| Plumas | 523 | Humana Inc. | 45.5% | 52 | 11.7% |
| Lassen | 467 | Humana Inc. | 73.9% | 51 | 8.9% |
| Siskiyou | 461 | UnitedHealth Group, Inc. | 36.2% | 58 | 8.1% |
| Inyo | 457 | UnitedHealth Group, Inc. | 42.7% | 53 | 13.9% |
| Glenn | 346 | UnitedHealth Group, Inc. | 47.1% | 51 | 10.9% |
| Del Norte | 226 | Imperial Health Plan of California | 39.4% | 50 | 5.4% |
| Colusa | 195 | UnitedHealth Group, Inc. | 69.7% | 51 | 13.3% |
| Mono | 96 | Humana Inc. | 47.9% | 53 | 9.1% |
| Sierra | 61 | Humana Inc. | 73.8% | 49 | 13.1% |
| Modoc | 59 | Imperial Health Plan of California | 55.9% | 52 | 5.2% |
| Trinity | 54 | California Physicians' Service | 40.7% | 50 | 6.9% |
| Alpine | 14 | Humana Inc. | 100.0% | 49 | 14.4% |
What is missing
CMS suppresses any plan-county cell with fewer than 11 enrollees. Those enrollees are missing from these counts, so every figure is a floor, not an exact total.
What is counted
Counts cover Medicare Advantage contracts only (Local CCP, Regional CCP, PFFS and MSA). Standalone Part D drug plans, cost plans, HCPP and PACE contracts are excluded.
Source: CMS Monthly Enrollment by Contract/Plan/State/County (CPSC).