An analysis of Medicare accountable care organization expense reports.

Objectives: To understand the investments that Medicare Shared Savings Program accountable care organizations (ACOs) in the ACO Investment Model (AIM) made to participate in the program and the costs that they incurred as a result of their efforts to lower spending and improve quality.

Study Design: We conducted a systematic review and categorization of all available and approved quarterly expenses reported by AIM ACOs.

Methods: We reviewed final approved quarterly expense reports submitted by ACOs detailing how they spent funds in the quarter. All distinct line-item descriptions were classified into a more informative and consistent set of categories. We then applied higher conceptual dimensions (type of care input and type of ACO strategy) to these newly categorized expenses to facilitate additional analysis of spending patterns.

Results: AIM ACOs reported expenses of $264.8 million over the 3 performance years (2016-2018). The majority of the $264.8 million in expenditures was incurred for personnel (55.5%), followed by infrastructure (22.3%), management firm expenses (15.3%), and internal programs and systems (6.9%). The dominant identifiable ACO strategy was care coordination and management, accounting for 52.9% of related ACO expenses.

Conclusions: AIM ACOs invested most heavily in personnel, information technology, and care management, with less than half of the investments explicitly tied to a strategy for improving quality or reducing spending. Efforts to change clinician practice patterns, alter the way patients access the health care system, and institute other practice redesigns were not primary targets for investment.