This working paper is a manuscript that was accepted for publication on May 31, 2023 in the American Journal of Health Economics (https://doi.org/10.1086/726268).

Dual Medicare-Medicaid enrollees face unique health care challenges compared with those enrolled in only one program, including greater medical needs and possibly less-than-ideal care due to administrative and financial misalignments across programs. The CMS Financial Alignment Initiative demonstrations are recent innovations aimed at improving health and health care for dual enrollees. One Care, the demonstration in Massachusetts, consolidates Medicare and Medicaid benefits into one insurance benefit package with several key features: care coordination and team-based care, new and innovative services, and plan performance incentives.

We study the effects of One Care on inpatient, outpatient, institutional, and home and community-based service (HCBS) utilization by exploiting the program’s distinctive age-based eligibility requirement using a regression discontinuity design. Results are consistent with general health and health care improvements. We find evidence of lower levels of emergency department use, greater likelihood of HCBS assessments, and greater intensity of home-based service use among those eligible for One Care. However, we find no evidence that One Care influenced inpatient service use. Our results suggest that the demonstration’s focus on promoting HCBS services may be more important to the demonstration’s success than either team-based care or performance incentives.