In emergency services, mutual aid is an agreement among emergency responders to lend assistance across jurisdictional boundaries.  This may occur due to an emergency response that exceeds local resources, such as a disaster or a multiple-alarm fire.  Mutual aid may be ad hoc, requested only when such an emergency occurs.  It may also be a formal standing agreement for cooperative emergency management on a continuing basis, such as ensuring that resources are dispatched from the nearest fire station, regardless of which side of the jurisdictional boundary the incident is on.  Agreements that send closest resources are regularly referred to as “automatic aid agreements”.

Mutual aid may also extend beyond local response. Several states have statewide mutual aid systems.  Examples include Washington and Oregon statewide mobilization programs.   MABAS (Mutual Aid Box Alarm System) is a regional mutual aid system, headquartered in Illinois, with 1500 member fire departments in Illinois, Indiana, Wisconsin, Iowa, Michigan, and Missouri.

MABAS was formed in 1968 in the northwest suburbs of Chicago.  Captain Donald Kuhn of the Elk Grove Village Fire Department proposed the system and managed its implementation.  Structured on Chicago box alarm cards that preassign the engines, trucks, squads, ambulances, and chiefs (and any other specialized equipment) to respond on a given level of alarm, MABAS adopted this simple model and still uses it today.

MABAS grew, and member departments were organized into divisions in the early 1970s.  Chicago-area divisions serve a dense area; departments within the division serve a geographic portion of the metropolitan area without regard to county boundaries.  These divisions usually consist of 12 to 20 departments.  Typically, once outside the immediate Chicago area, divisions are comprised of one or more counties.  The six-county Chicago metropolitan area has 18 of the total divisions.

Learn more about MABAS here.