Introduction: The increasing incidence of behavioral health conditions (BHCs) and worsening barriers to accessing comprehensive care highlight the need to integrate physical health, behavioral health, and social supports. This dissertation examines the facilitators and barriers to obtaining integrated care and to launching the Massachusetts Medicaid (MassHealth) Flexible Services (FS) Program (i.e., an integrated health-related social needs program), and assesses the effect of FS housing service receipt on healthcare utilization.

Methods: Data sources include semi-structured interview data obtained from MassHealth members and staff who launched the FS Program; FS documents; and administrative, eligibility, claims, and encounter files. Analytic methods include thematic analyses of interview transcripts, descriptive statistics, and overlap propensity score weighted regression modeling.

Results: MassHealth members with BHCs reported that limited social service and provider availability hindered care integration, but interdisciplinary collaborations and telehealth improved care. Staff emphasized that leveraging community-based expertise, data-driven referrals, and program flexibility facilitated the launch of the FS Program. Over the FS Program’s first three years, 93 nutrition and housing programs served nearly 30,000 MassHealth members. Members with BHCs who received FS housing supports had approximately 15% fewer hospitalizations, 17% fewer emergency department visits, and $2,200 lower costs while receiving services versus comparators.

Conclusions: These findings demonstrate that Medicaid programs can implement an integrated social support program, improving healthcare costs and utilization for adults with BHCs experiencing housing instability or homelessness. Programs may be more successful when leveraging interdisciplinary teams, telehealth platforms, risk stratification reports, expanding service availability, and allowing flexibility in program design.