Emergency management has evolved faster than many of the documents that guide it. If you redesigned your EOC on a blank whiteboard, factoring in modern hazards, staffing realities, and the tech you use every day, would the result match your current structure? For a lot of communities, it would not. And that is perfectly fine. EOCs should adapt as the work adapts, which is why choosing the right organizational model matters now more than ever.

In this blog, we’ll break down four common EOC organizational models, how they work, and what their pros and cons look like in practice. We hope this assists communities in picking the model that fits their current size, staffing, and operational reality.

Why Your EOC Structure Matters

An EOC is not the same thing as an incident command post. It is not managing the emergency scene but supporting the people who are. The organizational model you choose sets the tone for how your community coordinates information, allocates resources, and maintains situational awareness. A good structure clears confusion and creates calm. A poor structure does the opposite.

There is no national requirement for which EOC model you must use. FEMA offers guidance (see NIMS Third Edition Guidance), not mandates. As a local emergency manager, your task is to choose the EOC model that best fits your community’s size, staffing, capabilities, and emergency management maturity.

ICS Structure: Familiar, Flexible, and Widely Understood

Most people know the Incident Command System from response operations. Some communities use the same structure in their EOC with small adjustments. An EOC organized under an ICS model generally includes an EOC Director, supported by a Public Information Officer, and sections for Operations, Planning, Logistics, and Finance and Administration.

Pros

• Well understood by responders
• Highly scalable for small or large activations
• Straightforward training and documentation
• Clear lines of authority and responsibility
  

Cons

• Can feel too response-centric for an EOC focused on coordination
• Operations and Logistics sometimes blur because the EOC is not managing tactics
• Smaller communities may struggle to staff all sections

For many New England towns, ICS feels comfortable because it mirrors what fire and police already use. The challenge is making sure it truly fits the EOC mission rather than defaulting to what people already know from tactical response operations.

Incident Support Model (ISM): Designed for Coordination, Not Command

The Incident Support Model was developed to better reflect what modern emergency management does inside an EOC. Instead of replicating ICS, ISM builds around the mission sets of coordination. The EOC Director is supported by a Public Information Officer and sections for Situational Awareness, Planning Support, Resource Support, and Center Support.

Situational Awareness focuses solely on gathering, verifying, and synthesizing information. Planning Support uses that information to build products like action plans or briefings. Resource Support combines elements of operations and logistics into one branch focused on identifying and sourcing resources. Center Support handles internal needs such as staffing, IT, and administration.

Pros

• Purpose-built for EOC coordination and core emergency management missions
• Separates data gathering from planning, which reduces bottlenecks
• Reduces duplication by combining operations and logistics into Resource Support
• Works well for prolonged, complex, or multi-agency incidents

Cons

• Newer concept, less familiar to traditional responders
• Requires training to understand new terminology
• May feel too complex for small communities with limited staff (initially)

ISM can be a great fit for jurisdictions with higher coordination demands or where the EOC needs a consistent rhythm for long-duration events such as winter storms or public health responses. From my experience in a County Emergency Operations Center in Maine, the ISM model fit our operational reality from a staffing standpoint, but also reflected mission-sets were were well-positioned to carry out (situational awareness, public information, planning, resource support, and internal center support).

Department Specific Model: Simple and Intuitive for Smaller Communities

Smaller towns or counties often use a department-centered organizational model. In this structure, the Emergency Manager coordinates across departments such as public works, fire, law enforcement, EMS, public health, education, and others needed for the incident.

Pros

• Simple and intuitive
• Departments speak for their own capabilities and needs
• Minimal training required
• Fits communities where each department already functions independently

Cons

• Coordination can become siloed
• Information sharing may depend on relationships rather than structure
• Harder to scale for large or complex incidents

This approach mirrors how many New England communities naturally operate. The key is making sure cross-departmental coordination does not depend solely on who happens to be in the room.

ESF Model: Good for Larger Cities and Complex Operations

The ESF model aligns the EOC with the 15 federal Emergency Support Functions. It is common in state EOCs or large metropolitan regions, although it is intended for coordinating federal interagency support for a federal response to an incident. ESFs typically include ESF #1: Transportation, ESF #2: Communications, ESF #3: Public Works and Engineering, and so on. States sometimes add ESFs such as cybersecurity or private sector coordination.

Pros

• Clear grouping of functional missions
• Helpful for large communities with diverse partners
• Easy alignment with state and federal frameworks
• Scales well for multi-agency, multi-operational period events

Cons

• It can feel too broad for smaller jurisdictions
• ESFs sometimes overlap or create confusion about ownership
• Staffing every ESF may not be realistic in lower population areas

Tim Rieker’s recent blog points out the shortcomings of ESFs and highlights Community Lifelines as a more outcomes-focused way to think about essential functions. Lifelines such as safety and security, food, water and shelter, health and medical, and transportation offer a clearer picture of what truly matters in communities during disruptions. Some communities use a blended model that aligns operational groupings with the lifelines they prioritize.

Guiding Questions to Choose the Right Model

Before you pick an EOC structure or update your EOP, ask yourself:

• How is our EOC staffed during activations, and what roles can we realistically fill?
• Does our EOC manage tactics or coordinate resources and information?
• What structure do our partners use, and will alignment help or hinder us?
• How complex are the incidents we typically face?
• Do we need a model that supports long-duration operations?
• Does our current structure create confusion during response?

There is no wrong answer. The goal is to select the model that reflects your community’s operational reality while leaving room to grow.

Connect Your EOC Model Back to Your EOP

One of the biggest mistakes communities make is updating the EOP by simply replacing words in a template. Before you start playing mad libs with someone else’s document, step back and confirm that the operational model behind your EOP makes sense. The EOP should reinforce how your EOC functions, not contradict it.

If your EOC is organized by ESFs, your EOP should reflect those same groupings. If you operate departmentally, let that guide your annexes. If you use ISM, your planning documents should mirror those mission sets.

Structure first, content second.

Final Thoughts

Your EOC structure is more than a chart. It is the backbone of how your community coordinates response. Whether you use ICS, ESFs, a department-centered model, or the Incident Support Model, the structure should enhance clarity and reduce stress during an activation.

Choosing the right organizational model sets your team up for success. It helps people know where to plug in, what their role is, and how information flows. At Next Wave Preparedness + PDR Strategies, we help communities build EOC models and EOPs that match their real-world needs.

If you want help evaluating your current structure or exploring hybrid approaches that fit your jurisdiction, we are here to support you.