The foundation for effective dam safety assurance is an appropriate and well-designed regulatory framework that captures the legal, institutional, technical, and financial elements in the reality of a particular jurisdiction. Aging infrastructure, diminishing returns on new projects, changes in climate and weather patterns, and shifting trends of human settlement require ever-increasing attention in the effort to ensure the safety of dams and downstream communities. Establishing and maintaining a regulatory framework that is fit for purpose is, therefore, necessary for assuring the quality of dam design, construction, and operations. The framework also ensures that safety measures are reflective of the risks inherent in managing these structures and the context in which they are developed. Such frameworks need to be developed as part of a holistic strategy for water management that is integrated in basin and regional planning processes. The purpose of this Decision Support Tool is to guide countries and jurisdictions through various considerations in designing and updating their regulatory environment for dam safety assurance. This Decision Support Tool aggregates information derived from a comprehensive review and comparative analysis of regulatory frameworks in 51 countries. It presents a typology of situations that correlate with regulatory framework options along a continuum from minimum to maximum assurance of safety. It then presents hypothetical examples of how the Decision Support Tool can be used by countries and jurisdictions to assess their own situations and which regulatory options may be appropriate to consider for improving dam safety assurance.