Aetna Better Health of Illinois is one of the five statewide HealthChoice Illinois plans. It covers ABA under HFS’s Adaptive Behavior Support benefit for members under 21, and in February 2026 it rewrote its behavioral health utilization management for Public Act 104-0028: ABA assessments are approved on notice, and treatment moves to concurrent review.
Aetna Better Health’s February 20, 2026 notice says Public Act 104-0028 “establishes new requirements regarding utilization management and notification of behavioral health treatment,” effective January 1, 2026. For ABA: “For ABA assessments (97151, 97152), if Aetna Better Health of Illinois receives notification within one (1) business day of the start of the assessment, the service will be approved without medical necessity review. If notification is not received within one (1) business day, standard utilization review processes may apply. Concurrent utilization review will follow for ABA services requested after the initial assessment.” The same notice is explicit that “Authorization is still required for claims payment purposes.” Notify through the Provider Portal, by phone at 1-866-329-4701 (TTY 711), or by fax to 1-844-528-3453 for behavioral health.[12][13][2][14][15][16][17]
Illinois Public Act 104-0028 (HB 3019) changed behavioral health utilization management from January 1, 2026, and each HealthChoice Illinois plan has read it differently for ABA. Molina says ABA “services are no longer eligible for prior authorization and require concurrent review only” (no authorization for the initial assessment or the first 48 units of therapy a calendar year). Aetna Better Health approves 97151/97152 without medical-necessity review if notified within one business day, then runs concurrent review. Blue Cross Community Health Plans and YouthCare ask for notification within 24 hours of starting ABA services or the initial assessment. Meridian requires notice within 24 hours of 97151/97152 from May 1, 2026 and keeps prior authorization on treatment. CountyCare removed PA from 97151/97152 only. The Act itself added subsection (w) to 215 ILCS 5/370c: from January 1, 2026 “No policy shall require prior authorization for outpatient or partial hospitalization services for treatment of mental, emotional, or nervous disorders or conditions,” such coverage “may be subject to concurrent and retrospective review,” and “A Medicaid managed care organization may set a deadline of 24 hours after the initiation of treatment” for notification (one more business day if it cannot accept the notice). It also lets HFS “adopt rules to implement the applicable provisions” for managed care organizations “and the medical assistance fee-for-service program” (new 305 ILCS 5/5-5.28). The statute does not name ABA, which is why the plans differ; this guide reports each plan’s own written rule.[12][13][2][14][15][16][17]
The plan’s provider manual (titled the 2025 manual, posted at the 2026 address) sets the operational deadlines. New and corrected claims are due “within 180 days from the date of services”; claims with other insurance “within 90 days from primary insurer’s EOB date.” Clean claims are adjudicated 90 percent within 30 days and 99 percent within 90 days of receipt. Its UM table decides non-urgent pre-service requests “Within 96 hours of receipt of the request,” urgent pre-service within 48 hours, and concurrent reviews within 3 calendar days. Members (or a provider for them) may appeal “within sixty (60) calendar days” of the adverse benefit determination; standard appeals are answered within 15 business days. The manual lists the BACB as the credential it verifies for an “Applied Behavior Analyst.” Illinois law sets the payment clock for every HealthChoice Illinois plan: under 305 ILCS 5/5-30.1(g), “The MCO shall pay a claim within 30 days of receiving a claim that contains all the essential information needed to adjudicate the claim,” must notify the billing party within 30 days when it cannot adjudicate a claim, and owes a late-payment penalty at least equal to the Insurance Code’s timely-payment interest, calculated and paid within 30 days after the claim is paid, without the provider having to ask for it. No plan document we read publishes a weekly submission cutoff or check-run day; ask the plan’s provider services for its payment cycle.[3][1]
The questions that decide whether a family can start with Aetna Better Health of Illinois, and what they have to bring. Each maps onto something intake should ask on the first call.
Under 21: HFS covers ABS for children 0 through 20, and the plan publishes no different limit.[18][3]
The plan publishes nothing of its own. HFS: a CDE more than 24 months old needs current documentation of functional impairment by a physician or clinical psychologist.[3][4]
The plan publishes nothing of its own. HFS: the CDE is “performed by a physician or a clinical psychologist.”[3][4]
The plan publishes nothing of its own. HFS: the CDE results in an ADOS, GARS, ADI or CARS.[3][4]
The plan publishes nothing of its own. HFS requires a physician order and referral, valid one year.[3][4]
The plan publishes no ABA telehealth rule, so HFS’s applies. HFS’s ABS fee schedule (updated 05/14/2026) marks four codes for remote delivery: 97151 (assessment), 97155 (protocol modification), 97156 (family guidance) and 97157 (multiple-family group). The footnote reads: “Only use the GT or 93 modifier when providing allowable service remotely as a distant site telehealth service along with Place of Service (POS) 02 or 10, as applicable, on the specific service line of the claim.” 97152, 97153, 97154, 97158, 0362T and 0373T carry no telehealth modifier, so technician-delivered treatment is billed as in-person.[3][6]
The manual’s UM table: non-urgent pre-service decisions “Within 96 hours of receipt of the request,” urgent pre-service within 48 hours, urgent and elective concurrent reviews within 3 calendar days, post-service within 30 calendar days. Assessments notified within one business day are approved without review.[3][2]
“Aetna is the payer of last resort.” If other insurance is primary, “prior authorization of a service is not required unless it is known that the service provided is not covered by the primary payer”; then the plan’s PA rules apply. COB claims are due within 90 days of the primary insurer’s EOB, and the plan pays third-party copays, coinsurance or deductibles other than Medicare’s.[3][9]
Coverage decides whether Aetna Better Health of Illinois pays. These decide whether the claim survives: how sessions must be staffed and supervised, what may be billed concurrently, the per-day ceilings, who signs the note, where the service is payable, and whose NPI the claim goes out under.
The plan publishes no ABA supervision rule. HFS’s rule applies: RBTs “must receive supervision from a BCBA,” and HFS’s ABS guidance sets Case Leadership at “5%, or more, of all direct services” with at least two face-to-face contacts a month.[3][5][4]
The plan publishes no ABA-specific rule, so HFS’s applies: the rendering BCBA or RBT is reported by name and NPI, and when an RBT renders, the supervising BCBA’s name and NPI go in Loop 2310D, NM1. Every renderer must be enrolled in IMPACT.[3][4][5]
The plan publishes no ABA unit limit of its own. Claims adjudicate against the HFS ABS fee schedule, whose daily maximums are 97153 32 units, 97155 24, 0373T 24, 97156–97158 16, 97154 12, and 97151/97152/0362T 8.[3][6]
Ask the plan: Aetna Better Health of Illinois UM, 1-866-329-4701: ask whether the plan applies the HFS daily maximums.
Not addressed by the plan, and HFS publishes no rule beyond NCCI edits.[3][6]
Ask the plan: Aetna Better Health of Illinois Provider Services, 1-866-329-4701, or your provider agreement.
Not if you notify it within one business day of starting 97151 or 97152: the assessment is then approved without medical-necessity review (effective January 1, 2026). Late notice can trigger standard review.
Treatment goes to concurrent utilization review, and the plan says an authorization is still required for claims payment. Ask UM at 1-866-329-4701 how it wants the first treatment request submitted.
180 days from the date of service for new and corrected claims; 90 days from the primary insurer’s EOB when another plan pays first.
The plan publishes no ABA-specific rule, so HFS’s fee schedule governs: 97151, 97155, 97156 and 97157 with modifier GT or 93 and POS 02 or 10.
Payer policies change frequently and vary by plan, state, and funding type. This guide was compiled from the sources above and last reviewed October 2026; it is general information, not billing, legal, or clinical advice. Always verify current requirements against the payer's live policy and a benefits check for the specific member.
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