DALLAS (CBSDFW.COM) – Most so-called “surprise medical bills” are now illegal.

A new federal law that went into effect January 1, protects patients with insurance from unexpected out-of-network charges in most cases.

Patients still have to pay in-network costs but out-of-network costs are now prohibited for emergency care, elective care at an in-network hospital, and for air ambulances.

Ground ambulances were excluded from the new law.

According to a recent report from the Texas Department of Insurance, more than 85% of ground ambulances rides in Texas are billed as out-of-network.

For years, the CBS 11 I-Team has reported on North Texans who went to an in-network hospital for a treatment, only to blindsided weeks later with out-of-network charges.

“I was thinking my knee surgery would cost me out of pocket $2,500. It turned out to be $33,000,” Susan Howell told the I-Team in 2019. “”It’s eye opening to know somebody can just send you a bill for anything for a procedure and, if they make it out-of-network, they can ask whatever they want.”

Howell’s unexpected charges stem from an out-of-network physician assistant who helped with her surgery.

Howell said she was not told about the out-of-network expense prior to the procedure.

Two years ago, Texas lawmakers touted a new state law would protect patients from “surprise medical bills” but the I-Team found the state law only protected the less than one in five Texans who had state-regulated insurance.

The new federal law protects all insured patients from these unexpected charges.