What Is Master Street Address Guide (MSAG)?
MSAG (Master Street Address Guide) is a comprehensive database of street names, address ranges, and emergency service boundaries. It ensures 9‑1‑1 calls are routed to the correct Public Safety Answering Point (PSAP) and dispatched to appropriate responders.
Who Uses This System?
MSAG is maintained by GIS and Public Safety staff and used internally by 9‑1‑1 dispatchers and emergency personnel to validate caller addresses and identify service areas.
Key Features
Street names and address range listings
Emergency Service Number (ESN) mapping
Integration with GIS systems and NG9‑1‑1 dispatch tools
Maintains accuracy of address validation for emergency routing
Common Uses at the County
Maintaining accurate street and address data for dispatch
Linking incoming calls to PSAP zones based on ESNs
Supporting GIS updates and emergency system compliance
How Do I Access This?
MSAG access is restricted to GIS and Public Safety teams. To request changes or updates (e.g., new streets or address corrections), submit a request through the IT Service Desk or your GIS Coordinator.
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