Who’s in Charge? Event Medicine in the U.S.
When it comes to event medicine, before the first patient is seen, the choreography is already underway. Ambulances from multiple jurisdictions arrive at staging areas, crews check in, and assignments are handed out across a venue that functions more like a temporary city than a single site. Medical tents are staffed, transport units positioned, and communication channels established.
Each jurisdiction has a primary EMS provider responsible for 9-1-1 response. At large events, however, that provider is not always lead the overall medical operation. Event medical services may be managed by contracted providers or supplemented by outside agencies, with responsibilities distributed across multiple organizations, jurisdictions, and licensing structures. The system works—most of the time. But one question is not always clearly answered: Who is actually in charge of event medicine?
The Origins of Mass Gathering Laws
Mass-gathering laws in the United States were enacted to address public health risks posed by large crowds. Historically, those laws focused on preventing illness, ensuring sanitation, and maintaining safe environmental conditions for large groups of people gathered in one place, often for extended periods.
As a result, many jurisdictions established requirements related to potable water supply, restroom capacity, food safety, and waste management. Some also incorporated baseline medical expectations, including physician or nursing presence at large events, usually under the oversight of state or local health departments.
These frameworks remain important because they address environmental and public health risks that accompany large gatherings. Yet they weren’t designed for modern EMS operations. Most don’t address operational authority for prehospital medical care, integration between EMS and contracted providers, coordination across multiple jurisdictions, or documentation of patient encounters and system activity.
EMS in the Gray Space
As event medicine has evolved, the systems supporting it have become more complex and often extend beyond the scope of those original public health frameworks. In practice, EMS coverage at large events is shaped less by statute and more by local decisions, operational relationships, and experience.
Event organizers frequently contract with private practitioners and EMS providers to deliver on-site care. Those providers may bring personnel from multiple jurisdictions, operating under licensure compacts, mutual aid agreements, or temporary authorizations that allow them to practice within the host state.
The local EMS agency typically retains responsibility for patient transport, coordination with receiving facilities, and integration with regional systems such as medical communications centers.
In practice, these gaps are often managed through informal coordination. Pre-event meetings, direct communication between medical directors and EMS leadership, and reliance on experienced personnel help establish working relationships that may not be formally defined in regulation. While effective, these solutions depend heavily on local knowledge and professional familiarity rather than standardized systems.
The result is a layered model of care. Contracted providers focus on treatment on-site while local EMS agencies handle off-site transport and broader system coordination. Additional resources, including out-of-jurisdiction ambulances, fire services, and law enforcement, are integrated as needed. Coordination works because experienced professionals make it work—not because the structure itself is clearly established.
A Patchwork of Requirements
Public health regulations for mass gatherings are common, but EMS-specific requirements are far less consistent. Some jurisdictions require ambulance standby, submission of medical or emergency plans, or coordination with local EMS agencies as part of event permitting processes. In certain areas, these expectations are defined through local ordinances rather than statewide law.
Even so, no widely adopted framework across jurisdictions clearly defines EMS staffing levels, command structure, integration with contracted medical providers, or documentation practices. In practice, EMS involvement is expected but not standardized.
The National Association of EMS Physicians has published guidance on mass-gathering medical care, emphasizing the importance of medical direction, resource planning, and integration with local EMS systems. These principles are widely respected within the profession, but adoption varies. Two similar events in different jurisdictions may operate under very different models, with varying levels of coordination, staffing, and oversight.
How Event Medicine Actually Works
At most large-scale events, medical operations are divided functionally rather than hierarchically. On-site care is typically delivered through medical tents, first-aid stations, and mobile response teams staffed by a mix of EMTs, paramedics, nurses, and advanced practice providers or physicians.
Meanwhile, the local EMS agency stages transport units, manages patient movement to hospitals, and coordinates landing zones when air medical transport is required. Additional support from fire services, law enforcement, and emergency management may also be present.
What varies is how these elements are unified. At some events, a clearly defined Incident Command System (ICS) structure establishes leadership roles, communication pathways, and operational responsibilities. At others, coordination is less formal and relies more on experience, relationships, and real-time communication than on a documented command structure.
Where the Gaps Appear
Most of the time, these systems function without significant issues. Experienced crews adapt to the environment in front of them and keep operations moving. However, the absence of a clearly defined structure can create gaps that are not always obvious during routine operations.
Command relationships may be unclear, particularly when multiple organizations share responsibility for different aspects of patient care. Situational awareness beyond the event footprint may be limited, especially at the state or regional level. Communication between agencies may depend on improvised solutions rather than established interoperability. Documentation of patient encounters may vary widely, with some care captured formally and other interactions never entering broader reporting systems.
Why It Matters
Mass gatherings are inherently dynamic environments. Even under normal conditions, patient presentation rates can vary significantly depending on environmental factors and the characteristics of the attending population.
A hot-weather event with prolonged exposure, dense crowds, and alcohol consumption may generate a much higher volume of patient encounters than a cooler event with a different demographic profile. Age distribution, underlying health conditions, crowd behavior, and event duration influence both call volume and acuity.
When an incident escalates, the ability to respond effectively depends on more than clinical capability—it depends on structure. Clear leadership, established communication pathways, defined operational roles, and the ability to integrate with external resources become critical.
A Shift Toward Visibility
Addressing these challenges doesn’t require an extensive new regulatory system. In many cases, the necessary components already exist within the event itself. What’s often missing is visibility.
A practical approach would focus on improving awareness and coordination rather than imposing new requirements. This could include simple pre-event notification identifying key EMS and medical providers, a basic ICS-aligned structure with defined roles and contact points, a communications plan outlining interoperability, and a brief post-event summary describing activity and resource utilization.
A Practical Path Forward
Tennessee offers an example of a jurisdiction where there is a clear opportunity to build on existing frameworks without expanding regulatory burden. Event medicine can be approached through the lens of system awareness rather than system control. Identifying providers, clarifying roles, and documenting structure improves coordination without imposing new operational requirements.
A practical baseline should include pre-event information sharing with state or regional EMS oversight. This doesn’t require a new regulatory framework, but rather a consistent expectation that certain core elements are communicated in advance. These elements may include an ICS-aligned organizational structure, a communications plan, an event overview, and a medical plan outlining staffing and resource allocation.
In addition, a brief post-event summary capturing patient encounters, transports, participating EMS agencies, and the use of in-state, compact, or out-of-state personnel provides valuable system-level insight. This creates a snapshot of both planned capability and actual system impact, improving situational awareness without placing additional burden on event providers.
In the context of a large-scale incident or rapidly escalating event, that level of awareness allows state and regional systems to integrate more effectively, rather than building coordination in real time.
The Bottom Line
Event medicine in the United States works, often very well. It’s built on experience, adaptability, and the ability of providers to operate effectively in complex environments.
But in a system where large-scale events can rapidly escalate, reliance on informal coordination alone is not enough. A baseline expectation of visibility—knowing who is operating, how they are structured, and what resources are in place—should not depend on local relationships or institutional memory. It should be part of how we do business.
Because when an incident exceeds the footprint of the event itself, the question is no longer how well the event was managed—it’s how well the system can respond. In that moment, visibility is not optional. It is essential.
Resources
Margolis, A. M., Leung, A. K., Friedman, M. S., McMullen, S. P., Guyette, F. X., & Woltman, N. (2021). Position Statement: Mass Gathering Medical Care. Prehospital Emergency Care, 25(4), 593–595. https://doi.org/10.1080/10903127.2021.1903632
