Editor's note: This story was updated on April 6 to include data from the Texas Department of Insurance

The lawmaker who passed a law to save Texans from surprise medical bills after emergency room visits is concerned that freestanding centers are still exposing patients to financial risk.

Citing a Dallas Morning News investigation that showed standalone ERs are not clearly informing patients if the facilities are in-network or not, state Rep. Tom Oliverson, R-Cypress, has written to the state agency in charge of enforcing the law, which became effective more than six months ago.

“Upon reviewing some websites and seeing pictures of actual posted signage at some freestanding ERs, I too have concerns about the clarity of the information being provided to patients,” wrote Oliverson, whose bill garnered widespread support when introduced last year.

He is an anesthesiologist and a partner in US Anesthesia Partners, one of the state's largest anesthesiology groups.

House Bill 3276 required freestanding emergency rooms to state on their websites and at the facilities whether they are in-network or out-of-network for health insurance.

So far, the Texas Health and Human Services Commission hasn’t made clear how it will hold the facilities accountable.

Understanding in-network status is important for consumers, who could risk paying more out of pocket when they visit providers outside of their health insurer's network.

A survey of dozens of freestanding emergency room websites by The News that was done six months after the bill became law found confusing and misleading disclosures. In some cases, facilities had no disclosures at all.

The Feb. 26 report identified wide variation in the type of language the ERs used. But HHS, which licenses standalone facilities, had not cited any for deficiencies. Only 15 out of the more than 200 that exist in the state had been evaluated by regulatory inspectors at that time.

"It was not my intent that such disclosure and signage be accompanied by any additional information ... since this clearly makes the unambiguous statements about network status unclear," Oliverson wrote in his letter received by Texas HHS commissioner Charles Smith on March 23.

In his response to Oliverson less than a week later, the commissioner stated that if a state investigation finds a facility is not abiding by the law, HHS “will not hesitate to take action...to bring them into compliance.”

Smith said the agency has also issued a reminder to regulatory inspectors about the intent behind HB 3276 and guidance on “how to properly interpret it.”

The law aimed to help prevent consumers from the risk of being balance billed. That's when a health care provider directly charges the patient for what insurance won't cover. Last May, the legislature expanded a 2009 law that allows patients to get help for these "surprise" bills.

That mediation program, managed by the Texas Department of Insurance, now includes freestanding emergency facilities. The agency says last year more than 2,000 Texans submitted requests for mediation assistance to help with over $7 million in medical bills.