In a major emergency or a "high call volume" day, your local paramedics might be unavailable. Through a Mutual Aid Agreement, an ambulance from a neighboring jurisdiction will be dispatched to your house.
The Billing Surprise
Even if your local city handles your taxes, the responding city might bill you directly at their own rates. Because you didn't choose that provider and your insurance might not have a contract with that specific neighboring town, you are at high risk for a surprise bill for an out-of-network response.
Reciprocal Billing
Some progressive regions use Reciprocal Billing, where the two cities agree not to bill each other's Residents for out-of-pocket costs. However, this is the exception, not the rule. Most "Mutual Aid" calls result in a standard commercial bill being sent to the patient's home, often from a department the patient has never heard of.