Health Care Service Corp., the Blue Cross Blue Shield licensee for Illinois, Texas, New Mexico, Oklahoma, and Montana, decided in early 2026 that its prior authorizations for ABA therapy would now travel through a live phone call. According to Behavioral Health Business, the payer rolled the workflow out in April. HCSC covers roughly 27 million members across those five states, so the change lands on a lot of provider desks.
Fax is still allowed. HCSC’s own spokesperson confirmed as much. The company describes the phone call as “an enhancement to the provider experience” and says it intends to make the process permanent. For an ABA clinic trying to authorize a course of therapy for an autistic child, the five-page prior-auth form is still there, now with a phone call around it. The fax number the payer listed five years ago is the compliant off-ramp when the phone tree stalls.
What actually changed
The workflow, per BHB’s reporting, is a two-hop routing. A provider organization calls a scheduler. The scheduler books a call with a case manager. The case manager then works through the clinical elements of the prior authorization, one field at a time, on the phone. Clinicians, not just admin staff, are frequently required on the line.
By June, the sources BHB spoke to were describing bottlenecks. Scheduler callbacks were setting case-manager meetings several days out. In some cases the scheduler was returning the call and giving the clinic a 48-hour window to reach the case manager before the authorization would be denied.
“A lot of times what you’re doing is you’re redoing the work that you’ve already done,” one billing services professional told BHB. “You’ve taken all the supporting documentation, you’ve put together the authorization summary, and then on the phone you’re just walking through what is on the form that you have already filled out.”
Why fax is the quiet default
The paper trail everyone had already learned to run quietly became the fallback. HCSC’s spokesperson says the call is “not mandatory” and fax is still permitted. The practical result is that fax is what you reach for when the phone tree runs long.
In September 2025, federal HTI-4 rules landed with a January 2028 deadline to move US medical practices off fax and onto real-time digital communication with payers. The projected savings were around $19 billion over a decade, most of it in exactly the friction ABA clinics are now describing.
Ten months later, one of the country’s largest Blue Cross licensees added a phone call to its prior-auth workflow and quietly re-affirmed fax as the alternative. Fax never left US healthcare, where roughly 70% of providers were still exchanging patient information by fax when federal officials last put a number on it. HCSC’s workflow is a payer choosing, in 2026, to keep the fax route open because a five-page form and a fax number still work for the compliance record it needs.
Providers have theories about why. BHB’s sources mentioned a spending “lever” that slows ABA authorizations while state-mandated coverage keeps ABA volume rising, and a fraud-prevention filter that assumes real providers will pick up the phone. Those are theories, not disclosures. The disclosed fact is the workflow itself.
What it says about the pace of change
The federal deadline is January 2028. HCSC’s new process is dated 2026 and marked permanent. The two facts are not contradictory in any legal sense. HTI-4 is about the digital interfaces that will need to exist. It does not oblige a payer to stop accepting a fax that a provider chooses to send.
Fax stays in US healthcare not because a technology is winning, but because the payers who define the workflow keep choosing to leave it standing as the answer that clears the audit. For an ABA practice that just wants an authorization on the record before the 48-hour window closes, a working fax number remains, in 2026, a piece of infrastructure worth having.
For clinics that only need to send the occasional prior-auth form and would rather not stand up a fax stack of their own, a pay per fax service will still get the page across. That has not changed either.