Medicaid Waiver-Based Housing Supports in a Safety-Net Setting: Utilization and Spending Outcomes

Abstract Introduction States have expanded Medicaid waiver-based housing support programs, but evidence on outcomes in safety-net settings is limited. Methods We evaluated health care utilization and spending associated with Massachusetts Medicaid’s Flexible Services Program housing supports (FSP-H), provided to Accountable Care Organization (ACO) members with housing-related needs and qualifying health risks (2021-2024). Within a Boston-based safety-net health system, we linked FSP-H data to claims and electronic health records. Using staggered difference-in-differences, we compared monthly probability of inpatient and emergency department (ED) utilization and per-patient spending in FSP-H recipients (n=340) versus a contemporaneous comparison group with documented housing-related needs who were FSP-H-ineligible because they were in non-ACO plans (n=425). We conducted clinical risk-based subgroup analyses. Results Overall, FSP-H receipt was not associated with significant changes in monthly probability of inpatient utilization (-3.3 percentage points, p=0.223), ED utilization (-1.5 percentage points, p=0.569), or monthly spending (−$634, p=0.053). FSP-H was significantly associated with lower monthly inpatient utilization in the substance use disorder and frailty subgroups, and with lower monthly spending in the frailty subgroup. Conclusion Findings offer evidence for state Medicaid plans implementing or adapting housing programs.