Healthcare Insights
Top 25 ACOs by patient population
The healthcare landscape is changing, with a growing focus on accountable care organizations (ACOs) that prioritize quality care and cost-effectiveness. Organizations selling into the ACO market can maximize the impact of their efforts by prioritizing those that serve the most patients.
Keep reading for a data-driven analysis of the ACOs in the U.S. that serve the largest patient populations.
What are accountable care organizations (ACOs)?
Accountable care organizations are formal groups of physicians, hospitals, or other care providers that voluntarily work together to deliver coordinated care to a defined population of patients. ACOs are a key part of the move toward value-based care.
ACOs aim to ensure that patients—especially those living with chronic conditions—receive the appropriate care they need when they need it, while preventing unnecessary duplication of services, medical errors, and expenses.
Looking for a list of the largest ACOs in the U.S. ranked by patient population?
Using ConnectedCareView, we’ve compiled a list of the top 25 ACOs in the U.S. ranked by their total patient population, according to the most recent 12-month interval in our database.
| Rank | Definitive ID | ACO name | State | Patient population | Explore dataset |
|---|---|---|---|---|---|
| 1 | 810909 | TMA PracticeEdge (Texas Medical Association - Blue Cross and Blue Shield of Texas ACO) | TX | 5,000,000 | Explore |
| 2 | 842940 | Aetna - Childrens Hospital of Philadelphia (CHOP) ACO | PA | 1,400,000 | Explore |
| 3 | 552289 | Aetna - Carilion Clinic ACO | VA | 1,000,000 | Explore |
| 4 | 552388 | Capital Bluecross - Heritage Medical Group ACO | PA | 700,000 | Explore |
| 5 | 579844 | Anthem Blue Cross of California - Healthcare Partners ACO | CA | 675,000 | Explore |
| 6 | 579912 | Aetna - Riverside Health System ACO | VA | 500,000 | Explore |
| 7 | 585269 | Horizon Blue Cross Blue Shield of New Jersey - Partners in Care ACO | NJ | 500,000 | Explore |
| 8 | 823406 | Aetna - Virtual Medical Group ACO | NJ | 400,000 | Explore |
| 9 | 969400 | BCBS Illinois - Advocate Physician Partners Accountable Care | IL | 375,000 | Explore |
| 10 | 552285 | Advocatecare ACO | IL | 375,000 | Explore |
| 11 | 553402 | Cigna - Banner Health Network ACO | AZ | 350,000 | Explore |
| 12 | 969315 | BCBS Arizona - Banner Health Network ACO | AZ | 350,000 | Explore |
| 13 | 577487 | UnitedHealthcare - Seton Health Alliance ACO | TX | 320,000 | Explore |
| 14 | 969460 | HealthPartners - Northwest Metro Alliance | MN | 300,000 | Explore |
| 15 | 578002 | Partners for Kids ACO | NY | 300,000 | Explore |
| 16 | 585460 | Blue Shield of California - EPIC ACO | CA | 273,000 | Explore |
| 17 | 835846 | University Hospitals - Anthem Blue Cross and Blue Shield ACO | OH | 270,000 | Explore |
| 18 | 947978 | Cigna - DeKalb Physicians Health Organization | GA | 250,000 | Explore |
| 19 | 1002286 | Caravan Collaborative Pathways (AKA Caravan Health ACO 22 LLC) | TX | 246,471 | Explore |
| 20 | 552351 | Cigna - Westmed Medical Group ACO | NY | 237,000 | Explore |
| 21 | 553396 | OptumCare - North American Medical Management California ACO | CA | 229,000 | Explore |
| 22 | 1044880 | Caravan Health ACO 43 LLC | MO | 218,605 | Explore |
| 23 | 777076 | Health Choice Utah | UT | 200,000 | Explore |
| 24 | 856423 | Humana - John Muir Health ACO | CA | 200,000 | Explore |
| 25 | 574791 | Rainbow Care Connection | OH | 200,000 | Explore |
Fig. 1 Data from the Definitive Healthcare ConnectedCareView product. ACO data is sourced from the Centers for Medicare & Medicaid Services and proprietary research. Data accessed June 2025.
Which ACO has the largest patient population?
TMA PracticeEdge, a commercial ACO based in Austin, TX, has the highest patient population at 5 million as of June 2025. Aetna-Children’s Hospital of Philadelphia (CHOP) is in second place with a patient population of 1.4 million. Coming in third place is Aetna – Carilion Clinic, a commercial ACO based out of Roanoke, VA, with a population of approximately 1 million patients.
The top 25 ACOs by patient population on the list represent nearly 15 million patients with an average population of 694,763 patients each. Of the top 25, 21 are commercial ACOs, two are Medicaid ACOs, and two are Medicare Shared Savings ACOs.
How many ACOs are there in the U.S.?
Definitive Healthcare tracks more than 1,800 active ACOs across the U.S. Our list of accountable care organizations by state highlights the states with the most and fewest ACOs.
You can also review analyses of ACOs by state, including rankings of the top ACOs in Texas and the top ACOs in Florida.
What are the different types of ACOs?
ACOs cover patients who are covered by different types of healthcare payors. The main types of ACOs are:
- Commercial ACOs: Usually provider groups establish an accountable care payment model with a non-government payor.
- Medicaid ACOs: Aligns providers and payors incentives with a focus on value for a Medicaid population.
- Medicare Shared Savings Program: Requires measurement and improvement in quality and an annual certification process.
Learn more
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