Confused about billing behavioral therapy sessions that involve treatment modifications? It can be puzzling for many billers. That’s why our experts at MediBillMD have created this guide.
In this guide, we will discuss CPT code 97155, one of the most used codes in Applied Behavior Analysis (ABA) billing. By the end of this guide, we aim to clear all doubts surrounding this code. So, let’s start.
CPT Code 97155 – Description
CPT code 97155 is defined as:
“Adaptive behavior treatment with protocol modification, administered by a physician or other qualified healthcare professional, which may include simultaneous direction of a technician, face-to-face with one patient, 15 minutes.”
As evident from the definition, 97155 is an ABA therapy code. It is mostly used by Board Certified Behavior Analysts (BCBAs) or licensed behavior analysts. Under this code, the healthcare professionals perform real-time treatment plan modifications.
A key requirement of code 97155 is that the therapy session must be conducted face-to-face with the patient. Telehealth face-to-face sessions are also valid.
Unlike other ABA codes, 97155 is billed in 15-minute increments. It is used for one-on-one therapy where the qualified healthcare professional directly engages with the patient. Supervision does not count as engagement.
The protocol modification includes the following services:
- Adjust treatment goals, targets, reinforcement systems, prompts, materials, or environmental factors.
- Observe if the protocol is working. Document the components that were reviewed.
- Actively supervise technicians during implementation.
- Work with the patient to test if the protocol needs changes. Document reasoning if no modifications are required.
Scenarios Where CPT Code 97155 is Applicable
The usage of CPT code 97155 can be confusing, but we will try to simplify it with a couple of real-world scenarios where this code can be used.
Autism Spectrum Disorder
For our first scenario, suppose that a 7-year-old child is undergoing therapy for autism spectrum disorder. He visits the therapist for another face-to-face session. During the session, the therapist observes that the current protocol for teaching communication skills is not producing expected results. The child shows frustration and regression in previously learned behaviors.
Based on this new assessment, the therapist determines that real-time modifications are necessary to adjust the reinforcement strategies. To modify the treatment plan, the therapist works with the patient to change targets while simultaneously demonstrating the new protocol to the behavior technician present in the session.
In this scenario, the billing department can bill the entire ABA session via CPT code 97155.
Treatment for Maladaptive Behaviors
Let’s consider another scenario. Suppose an 8-year-old child is receiving therapy for maladaptive behaviors. During a session, he shows difficulty in problem-solving tasks. The supervising BCBA directly observes the child becoming increasingly agitated with the current intervention approach.
Based on his observation and the real-time data that he collected during the session, the provider decides that the treatment protocol requires immediate adjustment. So, he makes the necessary changes in the plan and instructs the technician about the new changes.
In this case, the entire session can be billed via CPT code 97155.
Applicable Modifiers for CPT Code 97155
The following are some modifiers that are used with CPT code 97155:
| Modifier | Description | Used By |
|---|---|---|
| HN | It indicates that the service was rendered by a provider whose highest degree is a bachelor’s level (BA or BS). | Licensed and Board Certified Assistant Behavior Analyst (BCaBA). |
| HO | It indicates that the service was rendered by a provider whose highest degree is a master’s level. | Licensed and Board Certified Behavior Analyst (BCBA). |
| GT/95 | Synchronous telemedicine service. | Used for real-time audio/video telehealth encounters. |
Please note that you cannot append modifier HM to CPT code 97155, as it represents that the service was rendered by a provider with less than a bachelor’s degree level of education or training. In other words, it indicates that a registered behavior technician (RBT) rendered the service. Since 97155 is a BCBA or BCaBA-specific code, an RBT cannot bill it even if present during the session. However, an RBT can use CPT code 97153 for ABA billing.
CPT Code 97155 – Billing & Reimbursement Guidelines
Oftentimes, overlooking simple billing guidelines leads to claim denials and lost revenue. The following are some essential points to consider while filing CPT code 97155 claims:
Provide Detailed Documentation
Like all claims, 97155 claims must be backed by comprehensive documentation. For proper reimbursement, you must add the following details to your claims:
- Session date and time
- Specific protocol modifications made with rationale
- Client response to modifications
- Objective data supporting changes
- Future treatment plan adjustments
Consider State-Level Regulatory Changes
Unlike many CPT codes, ABA therapy codes, and specifically CPT code 97155, are heavily impacted by state regulations. For instance, some states, like Virginia, have unbundled CPT code 97155, effective October 2025, creating new opportunities for separate billing of certain services.
So, remain updated with the changing regulations.
Wrapping Up
Let’s revisit all that we learned in this guide. CPT code 97155 is an ABA billing code. It is used to bill 15-minute therapy sessions in which the healthcare provider modifies the treatment protocol in a face-to-face setting. To get fair reimbursement for your services, you must append the appropriate modifiers and provide comprehensive documentation with your claims.
However, if you are still experiencing claim denials or administrative burdens, the best solution is to outsource your billing to specialized companies, such as MediBillMD. We provide premium ABA billing services that ensure a revenue increase.
