Indiana Medicaid ABA coverage: the intake guide.

Twenty and younger — and the cutoff just became real. The provider reference module covers ABA “for members 20 years of age and younger,” and BT202562 restates it. Effective April 1, 2026 ABA is covered exclusively through the EPSDT benefit; members 21 and older had a transition window through September 30, 2026, and for dates of service on or after October 1, 2026 IHCP will not authorize or reimburse ABA for members 21+. Age is therefore a first-call intake question in Indiana, and for a member approaching 21 the runway is a coverage fact worth stating out loud.^[2][1][3]

One year on the CDE, six months on the behavior assessment. BT202562: “if the CDE is more than one year old, an updated statement of need must be submitted. The statement of need must include a referral from an appropriate referring practitioner and an up-to-date behavior assessment completed by the ABA therapy provider.” Members continuing current services do not need a new CDE at all, but do need an updated behavior assessment and treatment plan; new behaviors or a request for services not previously authorized may require more frequent behavior assessments. Separately, “if a comprehensive behavior assessment has been completed within six months, any new provider is expected to obtain the assessment from the original provider” — so ask an incoming family who tested them and when before you re-test.^[3][2]

BT202562 names the credentials outright. The qualified healthcare provider performing the comprehensive diagnostic evaluation must have “specialized training in the application of the most recent Diagnostic and Statistical Manual of Mental Disorders (DSM) autism criteria” and hold one of: a doctoral-level licensed clinical psychologist endorsed as a health service provider in psychology (HSPP); a licensed physician; a licensed advanced practice registered nurse (APRN); or a licensed physician assistant. The provider reference module carries a slightly broader formulation that adds “other behavioral health specialist with training and experience in the diagnosis and treatment of ASD.” The behavior assessment is a different role with a different list — psychologist, BCBA-D or master's-level BCBA only.^[3][2][11]

Indiana is one of the few states that names the instruments, and it names three. The behavior assessment conducted before ABA starts “must include three core standardized behavior instruments”: the Vineland Comprehensive Parent Interview Form including the Maladaptive Behavior domain; the Behavior Assessment System for Children, Parenting Relationship Questionnaire (BASC PRQ); and an age-appropriate, objective direct skills assessment. It must be signed by the lead analyst and the parent or guardian, and “the complete scoring report, including outcome measure scores and graphs, must be submitted with prior authorization requests.” One currency note: IHCP accepts either the BASC-3 Parent Rating Questionnaire or its successor BASC-4 through October 1, 2026 — after that date only BASC-4 satisfies the requirement. The CDE behind the diagnosis has its own component list rather than a named tool: caregiver interview, structured observation of social communication skills and behaviors, review of available external evaluations or screenings, documentation of a completed DSM-based screening/diagnostic evaluation, and documentation that the individual cannot adequately participate in home, school or community activities or presents a safety risk.^[2][7][9]

Required, from a physician, and it appears twice. Member eligibility requires that “a physician has made a treatment referral recommending ABA therapy,” and the CDE’s own required components include “a physician’s referral for autism-specific services.” Where the CDE is more than a year old, the updated statement of need must itself carry a referral from an appropriate referring practitioner. All ABA services require prior authorization on top of the referral — through Acentra Health for fee-for-service, and through the member's MCE otherwise — with each PA limited to six months.^[2][3]

Indiana moved the other way from most states. Effective April 1, 2026, codes 97151, 97152, 97153, 97154 and 0373T can no longer be billed with telehealth modifier 95 — they require in-person delivery. That reaches the assessment and all direct and group treatment, which is why the 1-hour-per-8 supervision floor has to be staffed on site. Verify the current rule per code before scheduling; Indiana has revised its ABA policy repeatedly through 2026.^[1]

For fee-for-service members, the PA contractor is Acentra Health and the clock is federal-floor fast. From January 1, 2026 (BT2025165), Acentra must decide a standard request “within seven calendar days of the initial standard PA request,” extendable “up to an additional seven calendar days” only if the member or provider asks or Acentra requests more information; an urgent/expedited request must be decided “within 72 hours,” and “No pend (extension) time frame will be allowed for urgent/expedited FFS PA requests.” That matches 42 CFR 440.230(e). When Acentra pends a request for information, the clock restarts on receipt, and the information must arrive within 30 calendar days of the original request or “the request is systematically denied.” Reauthorization lead time is written down: submit new PA requests for continuation of ongoing services “at least 30 calendar days before the current authorization period expires,” and a denial or cut to a continuing service needs “at least 10 days’ notice plus three days’ additional mailing time.” Most IHCP ABA members are in managed care, where the module says to ask the MCE for its own time parameters — see the Anthem, CareSource and MHS guides (Indiana law gives MCEs a 48-business-hour clock).^[15][16][17]

Medicaid pays last, and Indiana enforces it by cost avoidance. The TPL module cites 42 CFR 433.139 for IHCP as “the payer of last resort” (only Victim Assistance, First Steps, CSHCS and CHOICE are billed after IHCP); if the eligibility check shows other coverage and the claim arrives without proof the other resource was billed, the claim is denied. Bill the commercial plan first, then send IHCP proof of the denial or payment — the EOB/EOP/RA or a qualifying adjustment reason code — including when the primary paid zero toward a deductible or copay; IHCP pays up to its allowable less the primary payment, and if the other insurer has not answered in 90 days the claim can go to IHCP with the billing evidence. Two ABA-critical rules: (1) get the IHCP PA anyway — “the provider must follow the primary insurer's requirements for obtaining PA and must also obtain PA from the appropriate IHCP PA contractor”; (2) be in the primary plan's network — IHCP “will not reimburse for claims that the primary carrier denied because the member received out-of-network services when the carrier required services to be delivered by in-network providers,” and the 90-day provision cannot be used to get around that. The pay-and-chase exception for preventive pediatric care, including EPSDT, only reaches claims carrying a diagnosis code from IHCP's “Preventive Pediatric Care Diagnosis Codes That Bypass Cost Avoidance” list; nothing in the module puts ABA on it, so bill the primary first. TRICARE is not a problem here: 32 CFR 199.8 excludes Medicaid from the “double coverage plans” TRICARE pays after, so for a child with both, TRICARE pays before Medicaid.^{[18][16][19][20]}

Two layers, and the second one is new money. The provider reference module requires that ABA performed by a BCaBA or credentialed RBT “must be under the direct supervision of a BCBA, BCBA-D or HSPP.” On top of that, since April 1, 2026 IHCP sets a numeric floor: at least 1 hour of BCBA (or IHCP-approved qualifying clinician) supervision per 8 hours of technician-delivered therapy. Because 97153 lost telehealth modifier 95 on the same date, that supervision capacity has to exist physically where the sessions happen. Assessments feeding a PA are a separate, narrower role: only a psychologist, BCBA-D or master's-level BCBA may perform the behavior assessment.^[2][1][3]

Indiana caps by the week and by the lifetime rather than by the day. Up to 40 hours per week may be requested; “ABA therapy services extending beyond 40 hours per week of direct therapy must be medically necessary and require an additional prior authorization.” Each PA is limited to six months — “PA requests for longer periods will not be approved.” Since April 1, 2026 comprehensive ABA (16+ hours/week, billed with modifier UA) draws from a 4,000-hour (16,000-unit) lifetime allocation per member, with 97155 and 97156 excluded from the allocation and usage visible in the IHCP Portal’s Limit Details panel; targeted ABA is capped at 15 hours/week and is exempt from the lifetime cap. Caregiver coaching is capped at up to 18 hours per standard six-month authorization. No per-day MUE ceiling is published. Additional hours outside the authorized PA may be requested for a limited period on a named list of triggers — a sudden increase in self-injury, aggression or elopement, regression in major self-care or language, a shift in family or home dynamic, or a non-mental-health health crisis or comorbidity.^[2][1][8]

School is in scope as a provider type, and out of scope as a duplicate. IHCP enrolls School Corporations (provider type 12, specialty 120) to bill ABA, and the treatment plan must be built around “the individual’s needs, age, school attendance (including homeschooling) and other daily activities.” But two named exclusions bound it: services “that focus solely on recreational or educational outcomes” are not covered, and neither are “services that are duplicative of other covered services, such as services rendered under an individualized educational program (IEP) that address the same goals using the same techniques as the treatment plan.” The plan must also document plans for parent/guardian training and school transition. Enrolled school corporations are exempt from the high-risk fingerprint screening, but group providers rendering ABA in school settings are not.^[2][11]

The claim goes out under the enrolled analyst or school corporation, never the technician. “ABA therapy services rendered by a BCaBA or RBT must be billed under the NPI of an IHCP-enrolled ABA therapist or school corporation,” and all ABA claims bill on a professional claim (CMS-1500 or its electronic equivalent). Indiana nonetheless makes technicians enroll individually: since December 18, 2024 the ABA specialties are 615 (Masters/Doctoral or HSPP), 624 (Bachelors) and 625 (RBT), and beginning July 1, 2025 reimbursement requires the rendering practitioner to be enrolled under one of them — except for school-based ABA billed by school corporations. Since April 1, 2025 the rendering NPI on the claim must align with the credential-level modifier (U1 RBT / U2 BCaBA / U3 BCBA-HSPP), though a bulletin update delayed enforcement of that alignment.^[2][1][11]

Not published in the ABA sections of the provider reference module or in the 2026 policy bulletins. Indiana does regulate code-pair economics from a different direction — the rendering NPI on the claim must align with the credential-level modifier (U1 RBT / U2 BCaBA / U3 BCBA-HSPP), and 97155 and 97156 are excluded from the 4,000-hour lifetime allocation while 97153 counts against it — but neither states whether 97155 and 97153 may be billed for the same clock time.^[2][1]

Ask the plan: For fee-for-service, Acentra Health at 866-725-9991 (PA) or Gainwell Customer Assistance at 800-457-4584 (billing), plus the Procedure Codes and Modifiers for Applied Behavior Analysis Therapy table in Behavioral Health Services Codes on the IHCP Code Sets page. For a managed-care member, the MCE — IHCP states that MCEs establish and publish their own billing and reimbursement requirements.

Indiana publishes signature rules for the plan documents but not for the session note. The behavior assessment “must be signed by the lead analyst and parent or guardian,” and so must the treatment plan; the complete scoring report including outcome measure scores and graphs must be submitted with the PA request. Neither the provider reference module nor BT202562, the bulletin titled for ABA documentation requirements, states who signs an individual session note or by when.^[2][3]

Ask the plan: Acentra Health at 866-725-9991 for fee-for-service, or the member's MCE, which publishes its own documentation and billing requirements. BT202562 also promises a future bulletin clarifying documentation requirements under the updated ABA State Plan Amendment — check for it before relying on this.