US
Office of Inspector General, Department of Health and Human Services
Published July 2025

Wisconsin’s Fee-for-Service Medicaid Payments for Applied Behavior Analysis

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Overall Conclusion

The Wisconsin Department of Health Services’ ForwardHealth program did not provide adequate oversight of FFS Medicaid ABA payments, resulting in improper and potentially improper payments for autism-related ABA services. The program had not conducted a statewide postpayment review since 2016, and supporting documentation deficiencies were prevalent across sampled enrollee-months, with estimated improper payments of at least $18.5 million and potentially improper payments totaling about $94.3 million. The findings indicate significant gaps in documentation, coding, and provider guidance, which could affect the quality of care for children with autism and the program’s financial integrity.

Source Document

Audit Scope

Audit covered the State agency’s total FFS Medicaid payments for ABA to enrollees 21 years and younger for the period January 1, 2021, through December 31, 2022, within Wisconsin’s ForwardHealth program. It analyzed 1,110,716 claim lines totaling $121.1 million ($80.8 million Federal share) across 36,345 enrollee-months. A stratified random sample of 100 enrollee-months (payments totaling $389,997; Federal share $258,035) was reviewed, encompassing 22 unique ABA facilities and 98 unique enrollees. The audit evaluated prior authorizations, diagnostic evaluations, prescriptions, plans of care, and session notes to determine compliance with Federal and State requirements, focusing on CPT codes (97151, 97153, 97155, 97156, 97156AM), session-note content and signatures, and provider rendering information. The audit did not assess medical necessity but sought to determine compliance with documentation and coding requirements and the adequacy of the State agency’s oversight (including postpayment reviews).

Key Findings Summary

1

Estimated improper payments totaling at least $18.5 million ($12,287,252 Federal share).

2

All 100 sampled enrollee-months included payments for one or more claim lines that were improper or potentially improper.

3

Estimated potentially improper ABA payments totaling approximately $94.3 million ($62,334,835 Federal share).

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AI-Assisted

Generated by gpt-5-nano

AI Scope Summary

Assess whether Wisconsin’s FFS Medicaid payments for ABA to children with autism, during 2021–2022, complied with Federal and State requirements, focusing on documentation quality, CPT-code billing accuracy, rendering-provider accountability, and the sufficiency of statewide postpayment review.

AI-Generated Insight

This audit reveals systemic gaps in Wisconsin’s oversight of ABA billing and documentation, highlighting a substantial financial risk ($112.8M across improper and potentially improper payments) and potential implications for patient care. It underscores the need for robust postpayment reviews, precise CPT-code guidance, and clear documentation standards to ensure both fiscal accountability and effective treatment for autistic children.