Evaluation of the Accountable Care Organization Investment Model

Project Overview

This project evaluated the Accountable Care Organization (ACO) Investment Model (AIM). It assessed whether infrastructure funding provided to AIM ACOs resulted in increased ACO participation in the Medicare Shared Savings Program (MSSP), sustained ACO participation in those programs that were previously MSSPs, and increased willingness by ACOs to accept greater financial risk. The evaluation also measured AIM’s effect on cost and quality and helped determine whether the model led to better care, healthier people, and smarter spending for Medicare and its beneficiaries.

Supporting Abt Associates, Insight led an analysis of healthcare markets that are conducive to ACO success and those that face greater challenges to implementing and achieving cost- and quality-related goals. As part of this market analysis, Insight examined the alignment of AIM ACOs with these markets. The analysis provided a rich source of market-level characteristics to support the selection of a comparison group of non-AIM MSSP ACOs for this study.

Insight also collected qualitative data with ACO leaders through interviews and site visits to determine program implementation, effectiveness, participation, and risk taking and effects on care, health, and costs. Specifically, Insight—

  • Conducted environmental scans on ACO market factors
  • Conducted a quantitative analysis of marketplace characteristics in AIM ACO markets and comparison markets
  • Led interviews with ACO leaders
  • Analyzed and summarized qualitative findings
  • Created reports for the Center for Medicare & Medicaid Innovation


Semiannual reports (2016, 2017, 2018, 2019, 2020); final report (June 2020); analytic files (August 2020)