Background/ObjectivesTransitions to and from Emergency Departments (EDs) can be detrimental to long‐term care (LTC) residents and burden the healthcare system. While reducing avoidable transfers is imperative, various terms are used interchangeably including inappropriate, preventable, or unnecessary transitions. Our study objectives were to develop a conceptual definition of avoidable LTC‐ED transitions and to verify the level of stakeholder agreement with this definition.MethodsThe EXamining Aged Care Transitions study adopted an exploratory sequential mixed‐method design. The study was conducted in 2015–2016 in 16 LTC facilities, 1 ED, and 1 Emergency Medical Service (EMS) in a major urban center in western Canada. Phase 1 included 80 participants, (healthcare aides, licensed practical nurses, registered nurses, LTC managers, family members of residents, and EMS staff). We conducted semistructured interviews (n = 25) and focus groups (n = 19). In Phase 2, 327 ED staff, EMS staff, LTC staff, and medical directors responded to a survey based on the qualitative findings.ResultsAvoidable transitions were attributed to limited resources in LTC, insufficient preventive care, and resident or family wishes. The definition generated was: A transition of an LTC resident to the ED is considered avoidable if: (a) Diagnostic testing, medical assessment, and treatment can be accessed in a timely manner by other means; (b) the reasons for a transfer are unclear and the transition would increase the disorientation, pain, or discomfort of a resident, outweighing a clear benefit of a transfer; and (c) the transition is against the wishes expressed by the resident over time, including through informal and undocumented conversations. There was a high level of agreement with the definition across the four participant groups.Conclusions and ImplicationsTo effectively reduce LTC resident avoidable transitions, stakeholders must share a common definition. Our conceptual definition may significantly contribute to improved care for LTC residents.