Objective: To examine the experience of Medicaid Accountable Care Organizations (ACOs) that include pediatric practices, including their motivations and experiences working together.

Methods: This mixed methods study is set within the first two years of the Massachusetts Medicaid ACO Program, which created 17 Medicaid ACOs across the Commonwealth in 2018. It combines qualitative interviews from organizational leaders across three Medicaid ACOs with pediatric representation (N=28; purposive sample; 2018) with a 44-item primary care practice leader survey (N=225 after 64% response rate; statewide stratified random sample of primary care practices; 2019). Interviews gathered information about organizational motivations and experiences with becoming a Medicaid ACO; the survey asked five domains of questions describing the experience of pediatric- and adult-focused primary care practices in joining Medicaid ACOs (e.g., how much practices solved problems jointly with the ACO). We used ordinary least squares regression to describe differences in experiences across pediatric vs. non-pediatric practices.

Results: Leaders of Medicaid ACO with pediatric representation expressed a desire to voice pediatric concerns regarding state Medicaid payment policy and to integrate social services as part of routine medical care. Relative to the experience of adult-focused primary care practice leaders, pediatric-focused practices reported less collaboration within the Medicaid ACO (95% confidence interval 0.81 to 0.05; p = 0.03) and less change toward standardization of policies such as physician compensation (95% confidence interval 0.61 to 0.02; p = 0.04).

Conclusions: Initial Medicaid ACO experiences can differ based on the degree to which organizations joining Medicaid ACO programs serve pediatric populations.

Article summary: Early in Massachusetts' implementation of Medicaid Accountable Care Organizations (ACO), pediatric-focused practices reported less collaboration and standardization within their Medicaid ACOs than adult-focused practices.