Research Objective
The ACO Investment Model (AIM) was designed to encourage providers in rural or underserved areas to participate in the Medicare Shared Savings Program (SSP) by providing up‐front financial support for care transformation. In the second performance year, there were 41 ACOs that continued participation in AIM, with 423,434 beneficiaries assigned them. Our research objective was to determine whether the significant reductions in total Medicare spending we found in the first performance year were sustained in the second year, and whether specific ACO or market characteristics were associated with spending in both performance years.
Study Design
We utilized a difference‐in‐differences evaluation design to estimate differences in total spending between Medicare fee‐for‐service (FFS) beneficiaries attributed to AIM ACOs and comparison beneficiaries, before versus after the start of AIM. The comparison group included beneficiaries residing in each AIM ACO’s market who were eligible but not attributed to an ACO. Regression and weighting were used to adjust for demographic characteristics and health status. We stratified first and second performance year results based on ACO and market characteristics, including whether an ACO used a management company; partnered with a hospital; had fewer than 6,500 enrolled beneficiaries; was in the top quartile of rurality among AIM markets; had a discontinuous market; or had total Medicare spending at baseline that was above the median among all AIM markets.
Population Studied
Medicare FFS beneficiaries attributed to ACOs in AIM, which targeted ACO formation in rural/underserved areas in 2016 and 2017.
Principal Findings
Across all 41 AIM ACOs, we estimated a significant reduction in total spending of $36.94 per beneficiary per month (PBPM) in the second performance year—a reduction of 3.5% and similar to findings from the first performance year. There were no significant differences in AIM impacts based on any of our six stratifications, but results across the two performance years suggest that greater reductions were achieved by ACOs working with a management company.
Conclusions
ACOs participating in AIM sustained reductions in total Medicare spending across the first two performance years and across diverse ACO and market characteristics.
Implications for Policy or Practice
Results from the second performance year strengthen the evidence that ACOs can help reduce Medicare spending in rural or underserved areas. Among AIM markets, variations in market‐level baseline spending, market dispersion, and high rurality were not barriers to achieving spending reductions. ACOs locating in rural or underserved areas may benefit through partnership with a management company.
Primary Funding Source
Centers for Medicare and Medicaid Services.
TTM. Multi-faceted ACP interventions that address all three ACP components, are matched to the client's stage of change, are timed earlier in the illness trajectory, and revisit ACP when changes in client condition (ie, relapse) occur are needed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.