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.