CHICAGO (CBS) — Michael Johnson was not pleased after he found an extra charge on his son’s dental bill.

The charge was a “behavior management” fee for Johnson’s 10-year-old son, who has autism. As CBS 2 Investigator Megan Hickey reported Tuesday, Johnson said he refuses to pay it.

“He has a lot of sensory issues,” Johnson said of his son, Wesley. “They say he’s never liked being on his back.”

Wesley, 10, has special needs and was diagnosed with autism. His therapist accompanied him to what they thought was a pretty routine dentist appointment in November.

“There was nothing that triggered a flag until the bill,” Johnson said. “There was a behavior management fee for $75 which, was the first time we’d seen that.”

Johnson said he had been taking Wesley to the pediatric dentist in Naperville for years.

And when they asked about the charge, Johnson said: “She said it was because he required some extra help. It took a little bit longer, so the appointment went late, and so they put that fee on.”

Johnson’s insurance provider wouldn’t cover the fee, and he said it feels like a form of discrimination.

“To get the extra charge is just frustrating,” Johnson said. “It feels like one more cost of having a child with special needs.

So what’s the deal?

Dr. Ian Marion of the University of Illinois at Chicago School of Dentistry said, “It’s something we know and talk about pretty regularly.”

Marion said it is a billing code that’s available to any dentist who runs their allotted time with a patient. And unfortunately it’s a code that is not reimbursed by most insurance providers.

“Ideally, that fee would be going towards extra staff and doctor time,” Marion said.

But Dr. Marion said that unlike Wesley’s case, the best practice is to explain the charge before the appointment if possible – and definitely before the bill comes.

“We know that people don’t like getting surprise bills, so being able to talk to them about what may happen during an appointment would always be a nice idea,” Marion said.

Dr. Marion said many dentists advocate for more insurance plans covering these fees.

We reached out to the dentist who treated Wesley for comment about the decision but as of Tuesday, there was no response.

Wesley’s dad says they’re going to keep fighting the fee.