Physician Participation in Medicare Accountable Care Organizations and Spillovers in Commercial Spending

The Longitudinal Impact Of A Multistate Commercial Accountable Care Program On Cost, Use, And Quality

The prevalence of accountable care organizations (ACOs) has grown significantly across Medicare and commercial payers in the past decade, but there are limited insights regarding the effect of ACOs on costs in the commercial population. We used longitudinal administrative claims data over the course of nineteen calendar quarters from 2016 to 2021 to assess the ongoing incremental impact of Elevance Health's commercial ACO program on cost and use across fifteen US states. We also analyzed the program's impact on spending subcategories (inpatient, outpatient, professional, and pharmacy) and measured differences in quality performance. The program was associated with incremental savings during this period. Incremental savings were greater in the fully insured population relative to the administrative services only population and were due to outpatient and pharmacy savings. ACO providers had superior quality performance measures relative to contracted providers not participating in ACOs. Payers should be aware of the potential for diminishing marginal returns of ACO contracting on containing health care costs.

Did Arkansas' Medicaid Patient-Centered Medical Home Program Have Spillover Effects on Commercially Insured Enrollees?

Patient-centered medical homes are increasingly being implemented by state Medicaid programs to incentivize high-quality, coordinated care and ultimately lower health care spending. This study examined whether the Arkansas Medicaid Patient-Centered Medical Home Program's practice-wide transformation activities had spillover effects on commercial beneficiaries. We used difference-in-differences to compare utilization and expenditures of commercially insured enrollees as their practices received Medicaid patient-centered medical home certification on a rolling basis between 2014 and 2016. We found a 5.7% increase in outpatient visits and 13% higher expenditures among early adopting practices. Even without associated reductions in costly emergency department visits or inpatient hospital admissions, decisionmakers should not lose sight of the potential value of increased engagement in and coordination of professional services for a population with high unmet health needs. Our results also emphasize that states can leverage Medicaid to spur system-wide transformation, and the investments generate spillover effects beyond those covered directly by Medicaid.