PROJECT SUMMARY/ABSTRACT Recent changes to National Institutions of Health (NIH) policy mandate the use of a single institutional review board (sIRB) for most federally funded multi-site studies. This policy change, it was argued, could increase research efficiency while enhancing protections for research participants. Although several studies have examined the impact of sIRBs on efficiency, critical questions remain regarding their impact on ethical protections for research participants. A key challenge for maintaining ethical protections of research participants in sIRB review is whether and how sIRBs can collect and incorporate knowledge of the local context. Concerns about local context that may affect the ethical conduct of research include knowledge about investigators, research settings, the resources and capacity to conduct a trial, and issues related to the vulnerabilities or concerns of local patient populations targeted for recruitment. NIH policies on sIRBs instruct participating sites to communicate “relevant information” to the sIRB regarding local context. However, there is no shared agreement as to the goals and content of local context review, or how this review should be tailored to particular study types or settings to best meet the twin goals of promoting efficiency while maintaining protections. As a result, there is considerable variation in how sites consider local context, raising concerns as to whether important issues are being missed, or, alternatively, whether some sites’ current processes introduce unnecessary barriers to the initiation of socially valuable research. The proposed bioethics research project will synthesize normative analysis, policy review, and empirical data from key stakeholders to develop guidance regarding the goals, content, and scope of local context review. In Aim 1, we will develop a conceptual model of the goals of local context review, its content, and the criteria by which to assess its relevance or appropriateness to specific study contexts. This model will inform our Aim 2 work, in which we will use a modified Delphi process to develop expert-informed guidance about what local context review should entail, and how it should be tailored to specific studies. The contribution of this research will be significant because it will lay the essential groundwork for efficient and ethical conduct of sIRB review. In doing so this will help advance the NIH’s broader commitment to enhance the quality and efficiency of clinical research.