When an ambulance responds to a 911 call, crew members will likely ask about symptoms and take the patient's blood pressure. One topic that probably won't come up in the conversation is money.

And that might lead to an unpleasant surprise later on. The fees charged by local fire departments and nonprofit hospitals typically run more than $1,000.

Allina, one of the largest ambulance service providers in the state, charges up to $1,900 for a typical ambulance ride. But its crews generally don't mention the fees unless asked. They probably don't even know what they are.

Allina Health Ambulance Operations Manager Dave Matteson navigated through traffic during an emergency call in Columbia Heights. Jeffrey Thompson | MPR News

"We don't get our EMTs and paramedics involved with the billing," said Brian LaCroix, who's in charge of Allina's ambulance service. "In fact, we don't want them to be. At the point when someone is needing an intervention, we are trying to focus on the care of that patient rather than their financial situation."

Allina is hardly unique. It's standard practice in the industry to talk medicine first and follow up later about the bill.

Kim Nuxoll was pregnant with her second child in 2006. She and her husband were at home in St. Paul when she realized the baby was coming — and soon. They called 911 in hope she could give birth in the hospital as planned, but her son arrived even faster than the ambulance.

"I did all the work," Nuxoll said. "I had the child before anyone even showed up. I had him bundled and warm and already nursing by that point. So the time for medical intervention had already passed."

Both she and the baby seemed fine, but they still needed to be checked out by a doctor. So when the paramedics offered to give them a lift, Nuxoll took them up on it — even though her husband was there and the car was already running.

Allina Health Ambulance Operations Manager Dave Matteson, left, assisted EMT Joseph Fortier and paramedic Kristine Reiff during a call. Jeffrey Thompson | MPR News

"Three months later is when we received information from our health insurance that said that [the St. Paul Fire Department] had claimed $1,153 for the ambulance ride for each of us," she said.

That's one bill for the mother and one for the newborn. They added up to more than the bill for the 11-hour hospital stay. The city even charged twice for mileage. Nuxoll says if she'd known it would cost so much, she probably would have just ridden with her husband.

The insurance company paid its 80 percent share without question. But Nuxoll contested her portion, with the help of a lawyer, and the fire department eventually waived it.

Most ambulance services in the state are run either by nonprofit hospitals or local governments. Only a handful are operated as for-profit businesses. As is the case with firefighters, in much of outstate Minnesota, many EMTs are volunteers.

St. Paul took in more than $11 million in ambulance fees last year. But the city estimates that amount covered only about half the cost of providing emergency medical service.

EMT Ruth Peka loaded gear into an emergency vehicle at the Allina Health Emergency Medical Services base in Mounds View. Jeffrey Thompson | MPR News

A new ambulance can cost $200,000 or more. And Kevin Miller, president of the Minnesota Ambulance Association, said that doesn't even count the expensive equipment on board, like machines for monitoring asthma patients.

"The monitor itself is $30,000," Miller said. "I tell the paramedics all the time, 'Don't drop that. That's going to be a big deal if you drop that.'"

The fees are the sole source of revenue for many ambulance services, although government-operated ones sometimes receive funds from local property taxes. And the fees typically come into play only when the ambulance actually goes to the hospital. There's usually no charge if the patient is treated on the scene.

Ambulance services across the state each have their own set of charges according to the level of care -- basic or advanced life support -- they provide in each case. A sampling, from left: St. Paul Fire Department, Hennepin County Medical Center, Allina Health EMS, Sauk Centre Ambulance Service and Sleepy Eye Ambulance Service. MPR News graphic

The association did a survey of its members a few years ago and found fees ranging from $450 to almost $1,900 for basic life support — the lowest level of emergency medical service. But those fees are often subject to steep discounts, Miller said, depending on the patient's insurance.

"And so it's not as though every dollar billed out is a dollar in revenue for ambulance services," he said. "In fact, right now, across the state of Minnesota, it is anywhere between 42 and 65 cents on the dollar overall."

Miller acknowledged that the bills for ambulance service can cause sticker shock. What patients are really paying for, he said, is the cost of having ambulances at the ready, 24 hours a day.

Map: Who's in charge of your ambulance service?

Where you live (or need help) largely determines which ambulance service arrives when you call 911. The Twin Cities metro area is carved up into territories served by more than two dozen ambulance services, run by fire departments, hospital systems and independent companies. Source: Allina Health