Revisions to the Common Rule and NIH policy require the use of a single Institutional Review Board (sIRB) for the review of most federally funded, multisite research, with the intent of streamlining the review process. However, since initial implementation in 2018, many IRBs and institutions continue to struggle with the logistics of implementing this requirement. In this paper, we report the findings of a workshop held in 2022 to examine why sIRB review remains problematic and propose possible solutions. Workshop participants identified several issues as major barriers, including new responsibilities for study teams, persistent duplicative review processes, the lack of harmonization of policies and practices across institutions, the absence of additional guidance from federal agencies, and the need for greater flexibility in policy requirements. Addressing these problems will require providing additional resources and training to research teams, the commitment of institutional leaders to harmonize practice, and policymakers to critically evaluate the requirement and provide flexibility in applicability.