In August, 2003, the U.S. Fire Administration (USFA) convened a focus group of stakeholders and experts from across the country to best determine the means to develop all-hazard Incident Management Teams (IMT) across the country.
An IMT is made up of the command and general staff memebers in an Incident Command System (ICS) organization. Person to fill these positions for various types of incidents or events are often pre-designated to ensure that they have the necessary training and experience to fulfill the roles and responsibilities of the ICS position. The level of training and experience of the IMT members are factors in determining the "Type" or level of IMT.
Type 4: City, County, or Fire District Level - a designated team of fire, EMS, and law enforcement officers from a larger and generally more populated area, typically within a single jurisdiction (city or county), activated when necessary to manage a major or complex incident during the first 6 - 12 hours, and possibly transition into a Type 3 IMT.
Source: U.S. Fire Administration