People with complex needs—a population that disproportionately experiences serious mental illness (SMI) and housing instability—face considerable barriers to accessing holistic services that can both help resolve short-term crises and address social determinants of health including access to housing. Without these services, this group often does not have their underlying vulnerabilities addressed. In addition, services are fragmented across social sectors that have limited ability to collaborate, often resulting in service gaps at critical points of transition. Different programs’ eligibility requirements create enrollment odysseys that would be challenging for the most fortunate among us to navigate, much less a person in crisis. As a result, many people with complex needs end up cycling between emergency shelters, psychiatric facilities, hospitals, and jails that—often at best only—attend to acute needs while underlying vulnerabilities largely or completely go unaddressed. This cycling continues at great personal and societal cost, in some cases over decades. Resources exist in every community that, if leveraged, could help meet immediate and long-term needs. Such services face chronic underinvestment related to a lack of evidence of their beneficial multi-sector impacts.  

CTIME findings will be an important contribution to a limited existing literature on how to effectively serve populations with complex behavioral health needs who lack access to stable housing. While a growing body of research evaluates applications of CTI in a variety of settings, most still largely focus on applications with smaller samples. Multisite evaluations—particularly those that monitor the fidelity of program implementation—have unique credibility with many research and policy audiences. Compared to single-site studies, multisite evaluations increase confidence that observed impacts can be attributed to the intervention itself and that program elements are robust to local contextual factors. When evaluated in two very different settings (e.g., urban and rural, state with Medicaid expansion and a state without it, etc.), a multisite study will provide policymakers with compelling evidence about where and for whom CTI should be scaled for the best results. The explicit comparison of CTI to existing “business as usual” models could also help make the case for federal funding of services through vehicles such as Medicaid waivers.