Grey County Paramedic Services is preparing for a new provincial ambulance dispatch system that will change how 911 medical calls are prioritized beginning this fall.
The Medical Priority Dispatch System, or MPDS, will take effect across the London Central Ambulance Communication Centre catchment area on October 14, 2026.
That area stretches from London to Craigleith and includes Grey County.
According to a report presented to Grey County council, the system is intended to better identify the most serious emergencies and direct paramedic resources accordingly.
"The goal of MPDS is to better triage and prioritize incoming calls for service and align resources to ensure availability to provide rapid response to the highest acuity patients," the report said.
MPDS will replace the existing Dispatch Priority Card Index system, which categorizes emergency calls primarily as Code 3 or Code 4.
Under the current system, Code 4 calls are generally dispatched in the order they are received. County staff said the new system will allow dispatchers to differentiate between various levels of urgent and life-threatening calls.
"MPDS allows us to break out the obvious and immediate threats," the report said.
Calls will instead be classified under five priority levels: Purple, Red, Orange, Yellow and Green.
Purple calls will include immediate life-threatening conditions, while Red calls will cover potential life-threatening emergencies. Orange calls will be considered urgent but unlikely to involve an immediate threat to life, while Yellow and Green calls will generally involve non-urgent conditions.
"The MPDS model prioritizes incoming call for service into a broader range of categories, identifying immediate and actual life-threatening emergencies and redirecting resources to the highest priority emergency in the area," the report said.
Grey County says one consequence is that people calling 911 with lower-priority medical needs may wait longer for an ambulance.
"Community members with low priority needs may experience delayed service responses," the report stated, adding that maximum wait times will be developed.
The county says the system is designed to preserve ambulance coverage for more serious emergencies while also improving the assignment of available paramedic units and the scheduling of inter-facility patient transfers.
Grey County has revised its Deployment and Utilization Strategy ahead of the change and has been working with local fire departments to ensure existing tiered-response agreements remain in place.
"The current level of response will remain relatively the same," the report said.
Paramedics and managers will also receive training, while a Grey County paramedic and manager will participate on a provincial Dispatch Review Committee.
More than half of Ontario has already transitioned to MPDS.
County staff say no immediate increase in paramedic staffing, fleet resources or funding will be required to implement the change.
