What federal auditors found in Medicaid ABA billing, and a monthly self-check for your own charts

A paid claim can feel finished. The session happened, the note was signed, and Medicaid paid. Federal audit reports show why an owner still needs one more question: if a reviewer pulled the chart later, would the record support the exact service, date, units, and provider that were billed?

The Office of Inspector General (OIG) at the United States Department of Health and Human Services has published state audits involving services for children diagnosed with autism. The reports are serious, but they need careful scope. They do not show that most applied behavior analysis (ABA) providers bill improperly. They test specific fee-for-service Medicaid payments in specific states and years against federal and state requirements.

What the four audits covered

Indiana report A-09-22-02002 was issued December 16, 2024, and reviewed fee-for-service Medicaid ABA payments from 2019 and 2020. OIG reported at least $56 million in improper payments.

Wisconsin report A-06-23-01002 was issued July 10, 2025, and reviewed 2021 and 2022 fee-for-service Medicaid ABA payments. OIG reported at least $18.5 million in improper payments.

Maine report A-01-24-00006 was issued in January 2026 and reviewed 2023 fee-for-service rehabilitative and community support services for children diagnosed with autism. Those services included ABA and other treatments. OIG reported at least $45.6 million in improper payments, so the Maine amount should not be described as ABA-only.

Colorado report A-09-24-02004 was issued February 25, 2026, and reviewed 2022 and 2023 fee-for-service Medicaid ABA payments. OIG reported at least $77.8 million in improper payments.

In each report, all 100 sampled enrollee-months included one or more claim lines that OIG classified as improper or potentially improper. That is a finding about each audit sample, not a rate for every provider or every Medicaid program.

The documentation themes that repeat

The reports apply different state rules, but several review subjects recur:

• Whether session notes supported the service dates and units paid
• Whether required signatures were present
• Whether the record supported Current Procedural Terminology (CPT) code 97155
• Whether the person who rendered the service and their credential were documented
• Whether billed time excluded non-therapy activities
• Whether required assessments, treatment plans, diagnoses, or referrals were on file
• Whether notes described the service, goals addressed, and data collected

Wisconsin's recommendations specifically discuss documentation for 97155, session-note support for units and dates, provider signatures, and verification of the rendering provider for 97153-focused treatment. Colorado's recommendations address documentation, billable time, provider credentialing, and diagnostic evaluations or treatment referrals. Maine's report includes findings involving comprehensive assessments, treatment plans, session-note content, non-therapy time, and credentials.

These are audit subjects, not a universal note template. Your state's current Medicaid manual, authorization, provider agreement, and applicable law still control.

A calm monthly self-check

Choose a sample that is appropriate to the practice's risk, claim volume, payer requirements, and compliance advice. One option is a fixed monthly sample, such as ten paid Medicaid charts from the prior month; another is a documented risk-based sample that changes with volume or findings. Whichever method the practice approves, include more than one provider and service code when appropriate. For each sampled date of service, ask:

• Does the note identify the client, date, setting, and person who rendered the service?
• Does the provider's credential and enrollment support the role shown on the claim?
• Do documented start and end times or duration support the units billed under the program's rule?
• Does the note describe the service delivered rather than only attendance?
• Does it identify the treatment-plan goals addressed and the data collected when the program requires them?
• For 97155, does the record support the work required by the applicable code and payer policy?
• Are required signatures, credentials, and dates present?
• Were non-therapy, recreational, academic, travel, or other excluded activities kept out of billable time under the state's rule?
• Were the required assessment, treatment plan, diagnosis, referral, and authorization current on that date?
• Do the authorization, schedule, note, and claim agree on the service, provider, date, location, and units?

This is part of stable billing: being able to explain what was paid and what supports it.

What to do with a failed check

Do not overwrite, backdate, or alter a historical note to make it look as though missing work happened. Preserve the original record. Any correction or late entry should follow the applicable documentation policy, state and federal requirements, payer instructions, your organization's approved procedure, and legal or compliance advice.

1. 1First identify the type of gap. A missing signature, unsupported unit, expired authorization, provider mismatch, and absent assessment are different problems.
2. 2Then determine whether the issue is isolated or repeated.
3. 3Check the current state rule and payer manual.
4. 4If the finding may involve an overpayment or reporting duty, involve qualified compliance or legal counsel.

This guide is not legal advice and does not state a repayment deadline.

Use the result to repair the upstream handoff. Keep the finding attached to its controlling policy, payer instruction, owner, and due date so the same gap does not quietly repeat. For the wider payment follow-up view, pair this chart-level check with what accounts receivable means in ABA billing. Accounts receivable tracks unpaid claims; this self-check asks whether a billed or paid service has supporting records.

Where this usually breaks

A chart may look complete when reviewed alone while disagreeing with the claim. The schedule names one technician, the note names another, the authorization is attached to a provider level, and the claim reports a different rendering record. Review the chain, not only the prose.

No self-check can guarantee payment or prevent an audit or repayment demand. It can give the owner a regular way to find unsupported or unclear records before the same gap spreads across more claims.

Want help finding the first place to check? Book a free billing review. No protected health information is needed.