The purpose of this NOFO is to support projects to test prospective multi-sectoral preventive interventions that address social determinants of health in populations that experience health disparities. These research projects will be part of the Multi-Sectoral Preventive Interventions (MSPI) Research Network, which will also include a Coordinating Center (NOFO xxx). Funded under a cooperative agreement, projects participating in the MSPI Research Network will collaborate to share approaches, methods, and data, working closely with NIH Institutes, Offices and Centers. Applicants applying to this NOFO are encouraged to review the Coordinating Center NOFO to fully understand the MSPI Research Network structure and activities. This NOFO solicits bi-phasic research projects proposed in UG3/UH3 Phased Innovation Awards Cooperative Agreement applications. Funding for the UG3 phase (phase I) will be used to demonstrate sufficient preparation, feasibility and capacity to meet foundational milestone targets specific to the work proposed. A UG3 project that meets its milestones will be administratively considered by NIH and prioritized for transition to the UH3 award (phase II). Applicants responding to this NOFO must address specific aims and milestones for both the UG3 and UH3 phases.