BackgroundThere has been increased attention to the need for, and the positive impact of, engaged or participatory science in recent years. Implementation scientists have an opportunity to leverage and contribute to engagement science (ES) through the systematic integration of engagement into implementation science (IS). The purpose of this study was to gather information from researchers and others to develop a prioritized list of research needs and opportunities at the intersection of IS and ES.MethodsWe conducted three Zoom-based focus groups with 20 researchers to generate a list of unmet needs, barriers, and to describe normative themes about use of ES and IS. Then a panel of nine experts in IS and/or engagement ranked the needs and barriers using a survey and met via a Zoom meeting to discuss and generate research opportunities and questions, with reference to the focus group outputs.ResultsRespondents and experts concurred on the importance of engagement in IS. Focus group participants reported 28 needs and barriers under the themes of 1) need for best practice guidance related to engagement processes and outcomes and 2) structural barriers to integrating ES in IS. The expert panel prioritized six structural barriers and four barriers related to generating best practice guidance, with corresponding recommendations on research opportunities. Example research opportunities related to engagement processes included: define “successful” engagement in IS contexts; adapt engagement tools and best practices from other disciplines into IS. Example research opportunities related to outcomes included: assess the impact of engagement on IS outcomes; examine engagement practices that lead to optimal engaged research. Example research opportunities related to structural barriers included: leverage research evidence to create structural changes needed to expand support for engaged IS; examine factors that influence institutional buy-in of engagement in IS.ConclusionsResearch needs exist that relate to engagement processes, outcomes, and structural barriers, even for scientists who value engaged research. Expert panelists recommended sequential and reinforcing research opportunities that implementation and engagement scientists can tackle together to advance both fields and health equity. Future work should assess insights from broader invested parties, particularly patients and community members.