[spzb]

One thing that's often overlooked is the cost of administering a billing system. If you're going to distinguish between the insured and uninsured you need a system that keeps track of who has insurance. You need paperwork (or digital equivalent). You need accounts payable staff to send invoices and chase up unpaid bills. It can, counter-intuitively, work out cheaper just not to charge anyone.

[charcircuit]

That is not required complexity. You can just send the bill to the customer.

[spzb]

Who is the “you” in this scenario?

[charcircuit]

The company offering the ambulance surface. Similar to how a pool cleaning company will send you a bill if you call them and have them clean your pool.

[spzb]

Generally, people who want their pool cleaned do so when they are conscious and have their pool very close to their home address. People who need ambulances are usually in a very different condition. That makes it a different prospect trying to chase payment.