Despite a growing national interest in health care-based strategies focused on patients' social determinants of health (SDH), little has been compiled about the impacts of SDH interventions undertaken in clinical settings. To understand better what is known in this area and incentives and barriers to related research, we conducted 30 semi-structured interviews with leaders and researchers in for-and non-profit organizations developing interventions to bridge health and social service delivery. Key informants described evaluation activities primarily concentrated on program design and implementation, and less commonly on impact evaluations and dissemination research. A diversity of outcome variables being used in intervention research limits the ability to draw conclusions about comparative effectiveness. Major barriers to advancing effective research on these topics relate to confusion around ownership of the SDH space within the health care sector.