There is a need for model uniform core criteria for mass casualty triage because disasters frequently cross jurisdictional lines and involve responders from multiple agencies who may be using different triage tools. These criteria (Tables 1-4) reflect the available science, but it is acknowledged that there are significant research gaps. When no science was available, decisions were formed by expert consensus derived from the available triage systems. The intent is to ensure that providers at a mass-casualty incident use triage methodologies that incorporate these core principles in an effort to promote interoperability and standardization. At a minimum, each triage system must incorporate the criteria that are listed below. Mass casualty triage systems in use can be modified using these criteria to ensure interoperability. The criteria include general considerations, global sorting, lifesaving interventions, and assignment of triage categories. The criteria apply only to providers who are organizing multiple victims in a discrete geographic location or locations, regardless of the size of the incident. They are classified by whether they were derived through available direct scientific evidence, indirect scientific evidence, expert consensus, and/or are used in multiple existing triage systems. These criteria address only primary triage and do not consider secondary triage. For the purposes of this document the term triage refers to mass-casualty triage and provider refers to any person who assigns primary triage categories to victims of a mass-casualty incident.