Ontario is planning to revamp its ambulance system to redirect some patients with less pressing needs to places other than emergency rooms.

The government announced Monday that its new system would start rolling out in March 2018 and would better prioritize calls based on patient need.

It says more than one million patients were transported by land or air ambulance in 2015, and only one per cent of them were the most critically ill and required immediate emergency transportation.

The Liberal government says it plans to update the Ambulance Act to allow paramedics to provide on-scene treatment and refer patients to primary care or community care, instead of hospitals, if appropriate.

The government says increased flexibility would reduce unnecessary trips to emergency departments, lessening overcrowding and easing wait times. It's estimated that fully implementing the system will take two years.