NIMS is the nation’s first standardized management approach that unifies federal, state and local government resources for incident response. SEMS is used throughout California to manage and coordinate any emergency response involving more than one agency or jurisdiction. NIMS and SEMS establish the Incident Command System (ICS) as a standardized organizational structure to establish a unified command and line of authority, with a common language and set of procedures for the management of all major incidents.
Use of SEMS during a disaster response is an eligibility requirement for local governments, agencies and special districts to receive STATE reimbursement following a disaster. A federal directive requires state and local governments and special districts to adopt NIMS in all preparedness, planning and response efforts.
National Incident Management System (fema.gov)