Evolving threats, such as Complex Coordinated Terrorist Attacks (CCTAs) and other High-Threat Active Violence Incidents, require a comprehensive "Whole of Community" approach to enhance readiness within the emergency management mission. Engaging all community stakeholders, inclusive of the private sector, public safety organizations, and the health and healthcare communities, is essential for risk reduction by preventing and limiting consequences from such critical incidents. The Joint Counterterrorism Awareness Workshop Series (JCTAWS) is a unique interdisciplinary table-top exercise sponsored by the Department of Homeland Security/Federal Emergency Management Agency, Federal Bureau of Investigation, and National Counterterrorism Center, and is designed to test plans and capabilities surrounding a CCTA. JCTAWS focuses on response integration between and across disciplines and jurisdictions. The workshop stimulates participant identification of best practices and gaps so that plans can be refined and resources realigned to improve response coordination for CCTAs.