Research SummaryWe conducted a multisite qualitative evaluation of the Overdose Detection Mapping Application Program (ODMAP) expansion states that received federal funding in 2019 to measurably augment, adopt, and/or use ODMAP in their service areas. Across five states, 11 agencies including law enforcement agencies, county health departments, and local health coalitions were invited to participate in in‐depth interviews to assess their experiences with ODMAP implementation, including facilitators, barriers, and best practices. Guided by implementation science principles and the Practical, Robust Implementation and Sustainability Model framework, we identified 12 key elements impacting progress toward ODMAP expansion, including the importance of leveraging interorganizational partnerships, competing environmental priorities, organizational perspectives on readiness for adoption, usability, and burden, organizational leadership support, and the presence of champions, dedicated implementation teams, and key adopter supports.Policy ImplicationsSince 2016, ODMAP has rapidly expanded in response to the opioid crisis. The system is currently used by a wide range of public safety and public health agencies including multiple state and county jurisdictions funded by the U.S. Centers for Disease Control and Prevention's Overdose Data to Action program. Ongoing, critical, and innovative evaluation of this nascent surveillance system is required.