Healthcare Insights

Top 25 ACOs by patient population

The United States spends more on healthcare than any other high-income country but has the worst health outcomes overall. In 2021, the U.S. spent 18.3% of its GDP on healthcare consumption, nearly twice as much as peer nations. Yet Americans still live shorter, less healthy lives.

There is no easy solution to this problem, but it’s one that healthcare providers are working to address through value-based care. Under value-based care models, reimbursement is linked to health outcomes. These models also place more emphasis on managing patient populations across the continuum of care using accountable care organizations (ACOs).

What are accountable care organizations (ACOs)?

Accountable care organizations (ACOs) 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? We’ve compiled a list of the top 25 ACOs in the U.S. according to their total patient population.

Top 25 ACOs by patient population size

RankACO nameACO typeStatePatient populationExplore dataset
1TMA PracticeEdge (Texas Medical Association - Blue Cross and Blue Shield of Texas ACO)Commercial ACOTX5,000,000Explore
2Aetna - Childrens Hospital of Philadelphia (CHOP) ACOCommercial ACOPA1,400,000Explore
3Aetna - Carilion Clinic ACOCommercial ACOVA1,000,000Explore
4Tampa Bay Health AllianceFL750,000Explore
5Capital Bluecross - Heritage Medical Group ACOCommercial ACOPA700,000Explore
6Anthem Blue Cross of California - Healthcare Partners ACOCommercial ACOCA675,000Explore
7Aetna - Riverside Health System ACOCommercial ACOVA500,000Explore
8Horizon Blue Cross Blue Shield of New Jersey - Partners in Care ACOCommercial ACONJ500,000Explore
9Aetna - Virtual Medical Group ACOCommercial ACONJ400,000Explore
10Advocatecare ACOCommercial ACOIL375,000Explore
11BCBS Illinois - Advocate Physician Partners Accountable CareCommercial ACOIL375,000Explore
12BCBS Arizona - Banner Health Network ACOCommercial ACOAZ350,000Explore
13Cigna - Banner Health Network ACOCommercial ACOAZ350,000Explore
14UnitedHealthcare - Seton Health Alliance ACOCommercial ACOTX320,000Explore
15Partners for Kids ACOMedicaid ACOOH300,000Explore
16HealthPartners - Northwest Metro AllianceCommercial ACOMN300,000Explore
17Blue Shield of California - EPIC ACOCommercial ACOCA273,000Explore
18University Hospitals - Anthem Blue Cross and Blue Shield ACOCommercial ACOOH270,000Explore
19Cigna - DeKalb Physicians Health OrganizationCommercial ACOGA250,000Explore
20Cigna - Westmed Medical Group ACOCommercial ACONY237,000Explore
21OptumCare - North American Medical Management California ACOCommercial ACOCA229,000Explore
22Rainbow Care ConnectionCommercial ACOOH200,000Explore
23Humana - John Muir Health ACOCommercial ACOCA200,000Explore
24Health Choice UtahMedicaid ACOUT200,000Explore
25University Hospitals Coordinated Care (AKA Aetna - University Hospitals ACO)Commercial ACOOH181,500Explore

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 August 2023.

Which ACO has the largest patient population?

TMA PracticeEdge, a commercial ACO based in Austin, TX, has the highest patient population at 5 million. Aetna-Children’s Hospital of Philadelphia (CHOP) has a patient population of 1.4 million and Aetna – Carilion Clinic, a commercial ACO based out of Roanoke, VA, has a population of 1 million patients.

The top 25 ACOs by patient population on the list represent more than 15 million patients with an average population of 613,420 patient each. Of the top 25, 22 are commercial ACOs and two are Medicaid ACOs.

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 establishing an accountable care payment model with a non-government payer
  • 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

Healthcare Insights are developed with healthcare commercial intelligence from the Definitive Healthcare platform. Want even more insights? Start a free trial today and get access to the latest healthcare commercial intelligence on hospitals, physician groups, ACOs, and other providers.