A new report from IQVIA has collected information on the largest accountable care organizations (ACOs) in the country based on the number of participating facilities, along with portions of organizational and professional rosters as well as the largest organizations in four of the ACO models offered by CMS.

“ACOs have significant control over decisions related to formulary, treatments, health IT adoption, sales-rep access, drug sampling policies, new product uptake and more,” the report said. “With so much at stake, service providers must understand how to position themselves in the eyes of these new and powerful stakeholders. A knowledge of their geographic coverage area, number of participants and ownership model is key to future engagement tactics and collaboration.”

Here’s the list of the 10 largest ACOs by total participating facilities:

1. Physician Organization of Michigan in Ann Arbor, Michigan: 303 total facilities
2. Advocate Physician Partners Accountable Care in Rolling Meadows, Illinois: 264
3. Healthcare Provider ACO in Garden City, New York: 199
4. Catholic Medical Patners—Accountable Care IPA in Buffalo, New York: 191
5. HCP ACO California in Chatsworth, California: 169
6. Asian American ACO in New York, New York: 168
7. Physicians Accountable Care Solutions in Suffield, Connecticut: 162
8. Caribbean Accountable Care in San Juan, Puerto Rico: 148
9. ApolloMed ACO in Glendale, California: 141
10. Delaware Valley ACO in Radnor, Pennsylvania: 134

The full report lists the 30 largest ACOs and can be found here.

IQVIA also identified the largest ACOs in several CMS models—the defunct Pioneer ACO and Advance Payment models as well as the ongoing Next Generation ACO and ACO Investment models. For the defunct models, the largest participants were relatively small ACOs—for example, the largest ACO in the Pioneer model, according to IQVIA, was the five-facility Beth Israel Deaconess ACO.

In the ACO Investment model, the largest participant was the 35-facility Illinois Rural Community Care Organization, based in Princeton, Illinois, which includes 22 hospitals and 11 medical groups. This model is open to ACOs in the Medicare Shared Savings Program, CMS’s largest ACO program, which was not included in IQVIA’s model-specific lists.

The Next Generation ACO model seemed to more of the larger ACOs. Its largest participant—the 96-facility UT Southwestern Accountable Care Network based out of Dallas—was ranked 23^rd nationally by number of participating facilities. The top five Next Gen ACO participants were all among the largest 100 ACOs in the country.