In Maryland, there have been no military/civilian training exercises of the Medical Mutual Aid Agreement for >20 years. The aims of this paper are to describe the National Disaster Medical System (NDMS), to coordinate military and civilian medical mutual aid in response to arrival of overseas mass casualties, and to evaluate the mass-casualty reception and bed “urge” capacity of Maryland NDMS Hospitals.

Three tabletop exercises and a functional exercise were performed using a simulated, overseas, military mass-casualty event. The first tabletop exercise was with military and civilian NMDS partners.The second tested the revised NDMS activation plan. The third exercised the Authorities of State Emergency Medical System and Walter Reed Army Medical Center Directors of Emergency Medicine over Maryland NDMS hospitals, and their Medical Mutual Aid Agreement.The functional exercise used Homeland Security Exercise Evaluation Program tools to evaluate reception, triage, staging, and transportation of 160 notional patients (including 20 live, moulaged “patients”) and one canine.

The first tabletop exercise identified deficiencies in operational protocols for military/civilian mass-casualty reception, triage, treatment, and problems with sharing a Unified Command. The second found improvements in the revised NDMS activation plan.The third informed expectations for NDMS hospitals. In the functional exercise, all notional patients were received, triaged, dispatched, and accounted in military and five civilian hospitals within two hours. The canine revealed deficiencies in companion/military animal reception, holding, treatment, and evacuation. Three working groups were suggested: (1) to ensure 100% compliance with triage tags, patient accountability, and return of equipment used in mass casualty events and exercises; (2) to investigate making information tech-nology and imaging networks available for Emergency Operation Centers and Incident Command; and (3) to establish NDMS training, education, and evaluation to further integrate and support civil-military operations.

The exercises facilitated military/state inter-agency coopera-tion, resulting in revisions to the Maryland Emergency Operations Plan across all key state emergency response agencies. The recommendations from these exercises likely apply to the vast majority of NDMS activities in the US.