This Department of Health and Human Services (HHS)-funded report provides an overview of the types of secondary data sources currently being used or that could potentially be used to evaluate interventions or conduct other analyses that address the five-part HHS strategy. The report highlights key research questions in each area and identifies opportunities to use existing data sources and implement data-linking strategies that can support assessments of the HHS strategy. Findings are based on interviews with 16 experts—academic researchers, federal researchers, and federal program officials—complemented by an environmental scan of the literature. This report does not address all the strengths and limitations of these data sources; rather, it is intended to provide sufficient information to serve as a resource to researchers in the field of opioids and opioid use disorder.