Identifying Beneficiaries of Accountable Care Organizations

By
Peter M. Hoang
Elbert S. Huang
August 20, 2026

Jama Network Open

Objective:

To investigate whether the establishment of accountable care organizations (ACOs) leads to a differential reduction in healthcare utilization between low-income and high-income patients.

Approach:

Study Design: Utilized Medicare data from 585 ACOs and over 35 million individuals from 2010 to 2019, employing a triple difference analytical approach.

Key Findings:

Low-income patients experienced 2 to 3 times the incidence of preventable ED visits and admissions compared to high-income patients prior to ACO formation.
Post-ACO formation, the reduction in preventable ED visits and hospital readmissions did not vary based on income status.
ACOs with significant baseline disparities showed improved outcomes for low-income patients over time without compromising care quality for higher-income patients.

Interpretation:

ACOs have not effectively reduced health inequities based on income status, indicating a need for program reforms.

Limitations:

The existing ACO model prioritizes performance metrics over addressing root socioeconomic disparities.
Challenges in implementing social health programs and insufficient data on patients' social health needs hinder ACO effectiveness.

Conclusion:

A research gap exists in understanding ACO heterogeneity and identifying factors that contribute to the effectiveness of certain ACOs for socio-economically disadvantaged beneficiaries.