Are organizations required to use National Incident Management System (NIMS) as an incident command structure?

The Joint Commission does not specifically require the use of the National Incident Management System (NIMS) for its incident command structure. Some organizations may choose to use NIMS as an incident command structure. If the organization is required to use NIMS by their state or local controlling authority, then per standard LD.04.01.01, the requirements of that controlling authority with regard to NIMS implementation must be followed.  

The Joint Commission's requirements for incident command at EM.12.01.01, EP 5 includes an incident command structure that describes the overall incident command operations, specific roles and responsibilities, and provides a structure that is flexible and scalable based on the needs of the organization during an emergency or disaster incident. Incident command staff are to be trained to be competent to effectively accomplish their assigned duties, command roles and responsibilities (EM.15.01.01, EP 4).