Illinois Ended Prior Auth for Outpatient Mental Health. Its Plans Split on ABA.

Since January 1, 2026, Illinois law has said “no policy shall require prior authorization for outpatient or partial hospitalization services for treatment of mental, emotional, or nervous disorders or conditions.” Every date in this story has already passed. What hasn't settled is what the law means for ABA, because the plans don't agree.

What the statute allows instead

Public Act 104-0028 amended 215 ILCS 5/370c. Coverage “may be subject to concurrent and retrospective review,” and a plan may require notice that treatment has started. For outpatient care:

• Commercial insurers may set a deadline of 2 business days.
• A Medicaid managed care organization may set 24 hours, with one additional business day if the plan can't accept notice in that window.
• “No such coverage shall be subject to concurrent review for any services furnished before an applicable notification deadline.”

The section never names autism or ABA. Every plan position below is that plan's own reading.

Four plans, four readings

• Molina Healthcare of Illinois (January 22): no authorization for the ABA initial assessment or “the first 48 units per calendar year for ABA therapy (cumulative of 0373T, 97153, 97154, 97155, 97156, 97157, 97158).” Molina says ABA is “no longer eligible for prior authorization” and requires concurrent clinical “no later than 24 hours after the initiation of the 49th unit.”
• Blue Cross Community Health Plans (January 12): for outpatient care “including... applied behavior analysis, providers should notify us within 24 hours of initiation of services.”
• Meridian (February 26): from May 1, notify within 24 hours of 97151 or 97152, and “failure to notify... will result in a denial of coverage.” But “all other ABA-related services and treatment plans are subject to prior authorization and/or concurrent review.”
• CountyCare issued three notices that don't line up. February: no authorization for 97151 and 97152, but ABA treatment “will require prior authorization.” February 6: “No prior authorization requirements for inpatient and outpatient behavioral services.” March: notify within one business day for 97154–97158, 0362T and 0373T. 97153 isn't on that list.

The limits

We couldn't retrieve Aetna Better Health of Illinois's notice. The Act lets HFS apply these provisions to fee-for-service Medicaid “at the Department's discretion,” and we didn't find a rule doing so. Notices may have been revised since they were posted. We aren't deciding which plan reads the statute correctly; that's a question for HFS, the Department of Insurance or an appeal.

What you must know or do

• Billing leads: write one row per plan and put it at intake. Molina: count units toward 48 and send clinical within 24 hours of the 49th. BCCHP: notify within 24 hours of starting. Meridian: notify within 24 hours of 97151/97152, and still request authorization for treatment. CountyCare: notify within one business day on 97154–97158.
• Pull every ABA denial since January 1 for missing authorization or late notice, and test it against that plan's own notice. A Meridian treatment denial for no authorization matches its notice. A Molina denial for no authorization inside the first 48 units doesn't.
• Ask CountyCare in writing whether 97153 needs authorization, notice, or neither. Its three notices point three ways, and you want the answer on paper before a denial.