ABA Therapy denial code (Updated for 2026)

Common Causes for CO 97

Denials with code CO 97 typically happen for the following specific reasons:

• Billing for concurrent ABA services, such as adaptive behavior treatment by protocol (97153) and protocol modification (97155), during overlapping time increments without distinct documentation of separate activities.
• Failure to append appropriate NCCI-associated modifiers (e.g., Modifier 59 or XE) to distinguish separate, non-overlapping services performed on the same day.
• Submitting claims for direct behavior identification assessment (97151) and treatment services on the same date of service in violation of payer-specific bundling rules.
• Billing group adaptive behavior treatment (97154) and individual adaptive behavior treatment (97153) for the same patient on the same day without clear evidence of separate sessions.

How to Prevent CO 97 Denials

To avoid receiving this denial in the future, implement these specific checks:

• Utilize precise electronic medical record (EMR) time-tracking to document exact start and stop times for all ABA codes, ensuring no overlapping minutes between distinct services.
• Append Modifier 59 or appropriate 'X' modifiers (such as XE for separate encounter) when billing distinct, non-overlapping therapeutic sessions on the same date of service.
• Perform routine pre-billing audits to verify that combined units of adaptive behavior services comply with the AMA CPT guidelines and local payer bundling policies.
• Train clinical staff to clearly document the unique therapeutic necessity and independent nature of supervision, protocol modification, and direct therapy when delivered on the same day.

Appeal Letter Template for CO 97

If you believe this claim was denied incorrectly, you can use the following template to submit an appeal.

[Your Practice Header]
[Date]

[Payer Name]
[Appeals Department Address]

RE: Appeal for Claim [Claim Number]
Patient: [Patient Name]
ID: [Patient ID]
Date of Service: [Date]
Denial Code: CO 97 - ABA Therapy denial code

Dear Appeals Department,

I am writing to appeal the denial of the above-referenced claim, which was denied with code CO 97: "ABA Therapy denial code".

We are appealing the denial of CPT code [Insert CPT Code] under denial code CO 97, which states the service is inclusive of another adjudicated procedure. According to the American Medical Association (AMA) CPT guidelines for Adaptive Behavior Services, concurrent billing of adaptive behavior services (such as 97153 and 97155) is clinically valid and reimbursable when a Qualified Healthcare Professional (QHP) provides direction to the technician during face-to-face patient intervention, or when services are administered during distinct, non-overlapping intervals. The attached clinical documentation and session logs explicitly detail the unique start and stop times, separate therapeutic goals, and independent clinical outcomes of each service. Because the documentation clearly demonstrates that these services were distinct and not duplicative, we respectfully request that this denial be overturned and the claim be reprocessed for full payment in accordance with CMS NCCI guidelines.

Attached please find:
1. A copy of the original claim.
2. The relevant medical records supporting the service.
3. [Any other supporting documents].

We respectfully request that you reprocess this claim for payment.

Sincerely,

[Your Name]
[Title]
[Practice Name]