How to Bill CPT Code 97151 for ABA Assessments

Billing for Applied Behavior Analysis (ABA) assessments can feel unnecessarily complex, especially when reimbursement hinges on getting one code right. Among all ABA billing codes, CPT code 97151 is one of the most important and most misunderstood. It forms the foundation of every ABA treatment plan, yet small mistakes in how it’s billed often lead to denials, delays, or underpayment.

This guide provides a clear explanation of how to bill CPT code 97151. If you’re a BCBA or you handle billing, you’ll learn what 97151 includes and how to file it correctly so it gets paid.

What Is CPT Code 97151?

Think of CPT code 97151 as the billing code for the full ABA assessment before treatment begins. It covers the behavioral assessment from initial observation through analysis and treatment planning.

The formal 97151 CPT code description includes:

• Time spent directly with the client and their caregiver

• Non-face-to-face time spent reviewing records, scoring assessments, analyzing data, and preparing the treatment plan

Each unit of CPT 97151 represents 15 minutes of a qualified healthcare professional’s time. This makes it a timed ABA therapy CPT code, similar in structure to other applied behavior analysis CPT codes.

Read more about ABA CPT codes.

When and Why to Use CPT 97151 

You should use the 97151 CPT code for ABA services in specific situations where an in-depth assessment is required.

Common scenarios include

• Initial ABA assessments for new clients

• Periodic reassessments required by insurance (often every 6–12 months)

• Significant changes in a client’s behavior or functioning

• Transitions between service settings that require a new treatment plan

This ABA CPT code should not be used for treatment sessions, parent training after treatment begins, or ongoing supervision. Those activities fall under other ABA therapy CPT codes. Understanding when to use billing 97151 correctly is critical. 

Learn more about ABA billing codes and MUE limits.

Using it outside of assessment activities is one of the most common reasons payers deny claims.

The Building Blocks of a Billable Assessment

Getting Your Face-to-Face Time Right

CPT code 97151 is billed in 15-minute units. Most payers follow the standard 8-minute rule, meaning:

• At least 8 minutes are required to bill one unit

• Additional units require full 15-minute increments

Accurate time tracking is essential. Even minor discrepancies can lead to audits or denials, especially when billing higher unit counts.

Know more about the 8-minute rule therapy guide.

What Your Documentation Must Include

Your documentation tells the story of your assessment. Insurance companies expect a clear, complete narrative that supports medical necessity and accurately reflects the time billed.

• Start with your observations. Document what you saw in the client’s natural environment. 

• Include results from standardized assessments such as VB-MAPP, ABLLS-R, AFLS, or similar tools, along with your clinical interpretation.

• Document caregiver and teacher input to show how behaviors appear across different environments.

• Review medical and developmental history, including prior diagnoses, milestones, and past assessments.

• When applicable, add a functional behavior assessment explaining what maintains challenging behaviors.

• End with your professional analysis and treatment recommendations, showing why CPT code 97151 is appropriate.

  Learn more about the importance of strong ABA documentation for compliant ABA billing, which helps protect claims during reviews.

Step-by-Step Billing Roadmap

Step 1: Get Your Authorization First

• Most insurance plans require prior authorization before an ABA assessment.

• Submit client demographics, insurance details, referring provider information, and the diagnosis code (usually F84.0 for Autism Spectrum Disorder).

• Request the right number of units, usually 8–12 units, for an initial assessment.

• Start this process early. Don't schedule your assessment until you have that authorization number in hand.

Step 2: Conduct Your Assessment and Document Everything

• Track exact start and end times for all face-to-face assessment activities.

• Document which assessment tools you used and what results you got. Write down your behavioral observations with specific examples. If the child threw materials three times during the session, note that. If the parent described bedtime as taking two hours nightly, write it down.

• Track your non-face-to-face time too. When you sit down to analyze data, note the time. When you write your report, track those hours. This documentation protects you if questions ever arise about your billing.

• When you're doing the assessment, keep your timer handy. Record exact start and end times for every face-to-face activity.

Step 3: Calculate Your Total Units

• Add all face-to-face and non-face-to-face time together.

• Convert to units: 300 minutes divided by 15 minutes per unit equals 20 units of CPT 97151.

• Double-check your math before billing to avoid errors or denials.

Step 4: Submit Your Claim

• Bill CPT code 97151 with the correct number of units.

• Include the appropriate diagnosis code and place of service (03, 12, or 11).

• Verify rendering provider NPI, credentials, authorization number, and service dates.

• Submit the claim through your clearinghouse or payer portal.

Step 5: Track Your Claim Status

• Check claim status regularly through the clearinghouse or payer system.

• Follow up if payment is delayed beyond the normal processing time.

• Review the explanation of benefits carefully for denials or underpayments.

• Appeal with supporting documentation if needed.

Can CPT Code 97151 Be Used for Telehealth or Virtual Assessments?

Telehealth rules for ABA CPT codes are payer-specific.

Some insurers allow limited virtual components, while others restrict CPT code 97151 to in-person assessments only. Always verify telehealth policies before billing virtual services under this code.

Assuming telehealth coverage without confirmation is a frequent source of denials.

FAQ

1. What is the difference between 97151 and 97152?

CPT code 97151 covers the BCBA’s assessment work: interviews, observation, testing, and the written report. CPT code 97152 is technician support, done face-to-face under supervision.

2. How often can you bill CPT 97151?

Usually at intake and when a reassessment is clinically needed. Frequency depends on payer rules and authorization. Don’t repeat it without clear documentation.

3. What is the CPT code for ABA therapy evaluation?

For an ABA evaluation, the important CPT code is 97151. It covers the behavior identification assessment that supports diagnosis, baseline data, and treatment planning.

Conclusion

CPT code 97151 sits at the center of ABA assessment billing. When used correctly, it supports accurate reimbursement for the most clinically intensive part of ABA care. When used incorrectly, it leads to denials, audits, and lost revenue.

By understanding the 97151 CPT code description, tracking time carefully, documenting thoroughly, and following a structured billing process, ABA providers can protect their income and reduce administrative stress.