ABA Billing Codes: 10 Main Codes + Guidelines You Need
Your billing team shouldn't spend hours chasing down claim denials.
When you understand ABA billing codes and payer requirements upfront, claims get paid the first time.
Learn the essential ABA therapy codes and documentation standards, so you can skip the headache.
What ABA billing codes are and why they matter
ABA billing codes are the codes therapy practices use in claims that tell insurance companies what services they provided. They describe the type of session, who delivered it, and how long it lasted.
Using the wrong code or documenting it incorrectly leads to claim denials. But when your codes match your session notes and payer rules, claims move through the system smoothly.
The result? Your clinic gets paid faster.
Tools like Passage Health’s practice management software can keep your codes, authorizations, and notes in sync across multiple payers or client locations.
How CPT codes work in ABA therapy
The American Medical Association (AMA) creates and maintains Current Procedural Terminology (CPT) codes. Annual updates to CPT codes reflect changes in healthcare practice.
ABA therapy CPT codes are grouped into two main categories:
- Assessment codes, used when conducting initial evaluations or reassessments
- Treatment codes, used for therapy delivery, supervision, or caregiver training
The core ABA CPT codes (and how to use them correctly)
ABA billing has 10 main CPT codes that most clinics use regularly. Make sure to check your payer’s guidelines for documentation tips, or reference the CASP note templates as a starting point.
Here’s how to understand and apply the CPT codes in practice.
Assessment codes in ABA billing
Treatment codes in ABA billing
What’s new for ABA therapy codes in 2025?
There are a few notable updates that affect ABA billing in 2025:
- Extended telehealth coverage: CMS confirmed that telehealth delivery will stay covered for ABA services through at least December 2025. Rural Health Clinics (RHCs) and Federally Qualified Health Centers (FQHCs) can bill this service by using HCPCS code G2025.
- Greater documentation scrutiny: Insurers are focusing more on session notes. Incomplete or vague documentation is one of the top reasons for recoupments. Every note must clearly support the CPT code billed.
Future updates to look out for
The ABA Coding Coalition (in collaboration with the ABAI Billing Codes Commission) announced major changes to the ABA services code set at its September 2025 meeting.
These revisions include the addition of 6 new CPT codes, revision of the existing CPT codes, and deletion of the existing “T” codes.
The changes will go live January 1, 2027, and will be published in the 2027 CPT Professional Code book (due late 2026).
ABA billing guidelines
Here are the best practices for documentation, time units, and provider qualifications so you can get billing right.
Documentation
You can protect your clinic during audits and receive timely payment. It requires accurate documentation.
Here’s what to include in every session note:
- Client information: Full name, ID, and service date
- Provider information: BCBA or RBT name, credential, and role
- Start and end time: Exact times that match the units billed
- Service code: The correct ABA billing code for that activity
- Session goals: Which treatment goals were addressed
- Progress notes: What the client did, how they responded, and any plan changes
Signature: Digital or physical signature of the provider
Ask yourself: Can an auditor tell what happened in the session? If they can’t tell just by reading your note, it needs more details.
Billing in 15-minute units (and the 8-minute rule explained)
Most ABA codes are billed in 15-minute chunks, which are called “units.”
But insurance doesn’t require the time to land perfectly on a multiple of 15. Instead, it follows what’s called the 8-minute rule. You can bill for a unit of time-based codes once you’ve provided at least 8 minutes of service in that 15-minute block.
Here’s how the 8-minute rule breaks down:
- 0-7 minutes = 0 units
- 8–22 minutes = 1 unit
- 23–37 minutes = 2 units
- 38–52 minutes = 3 units
Overbilling by even a few minutes can flag your clinic for audit, especially with payers that track utilization closely.
Thankfully, if you use billing software like Passage Health, you won’t spend so much time calculating units. The system will automatically calculate the unit for you based on the payer’s unit rules.
Who bills for what in ABA therapy?
BCBAs and RBTs bill for different services:
- BCBAs typically bill for assessment, supervision, or direct modification sessions (codes like 97151 and 97155).
- RBTs or technicians bill for direct implementation of the plan (like 97153).
Insurance payers often require that a BCBA bills their time separately from technician hours, even if they occur during the same session. The provider credentials tied to each code matter as much as the code itself.
Common ABA billing mistakes and how to prevent them
Even experienced billing teams make errors that can cost clinics thousands each year. Watch out for these mistakes:
Billing incorrect time units
Always bill based on actual time, not rounded estimates. Keep electronic time logs or use integrated scheduling tools that calculate units automatically.
Confusing BCBA and RBT roles
Supervisory services and direct implementation are billed differently. If an RBT bills a BCBA code, the claim will be denied.
Missing signatures or credentials
Payers often reject claims missing provider credentials or electronic signatures.
Incomplete authorizations
Before starting services, confirm that the insurance authorization covers the right code and number of units. Submitting unauthorized codes leads to automatic denials.
Generic progress notes
Phrases like “client participated well” don’t justify a billed service. Notes should show progress with data and specify which behaviors or goals were targeted.
Outdated software or spreadsheets
Manual systems can’t catch errors like mismatched units or expired authorizations. Billing software is your first line of defense.
How to keep billing clean and compliant all year
- Standardize your note templates:
Every clinician should use the same documentation structure. This reduces confusion and makes billing reviews faster. A billing software will give you customized templates that help standardize your documentation. - Audit regularly:
Review a set number of claims each month. Check time, documentation, and authorization accuracy to catch and correct small errors early. - Confirm payer rules:
Each insurer has slightly different requirements for modifiers, supervision, and time limits. Keep a shared reference sheet for your billing team. - Submit claims quickly:
Aim to submit within a set schedule that works for your clinic. The faster your team submits, the faster you can get paid for services and prevent missing timely filing. - Train your team before January:
New CPT changes always go into effect on January 1st. Review updates and train your team in December to keep your clinic ahead.
Why the right ABA billing software makes all the difference
Most billing problems come from scattered systems, with notes in one platform, schedules in another, and insurance data somewhere else. The disconnect creates room for error.
With a unified billing software like Passage Health, you can manage everything in one place. This reduces manual entry, cuts claim denials, and helps your clinic maintain compliance with less effort.
Our all-in-one ABA platform offers:
- Accurate code management that reduces billing errors
- Faster claim submission through automated workflows
- Real-time revenue tracking so you know what’s paid and pending
- Simplified team collaboration between clinicians and billing staff
When your tools work together, your billing becomes reliable and transparent.
Learn how Passage Health’s practice management platform can simplify your billing process today.
Frequently asked questions
- How often do ABA billing codes change?
ABA billing codes change every January. The ABA Coding Coalition publishes upcoming updates in the fall.
- What’s the difference between 97153 and 97155?
Use 97153 when a technician delivers adaptive behavior treatment by following the treatment plan directly. Use 97155 when a BCBA delivers treatment and modifies the protocol during the session.
- Are ABA CPT codes the same in every state?
Yes, ABA CPT codes are standardized nationally. However, reimbursement rates and payer requirements vary by state and insurance plan.
- How should I submit ABA therapy codes to insurance?
Submit ABA therapy codes electronically through billing software or a clearinghouse for the fastest, most accurate processing. Paper claims take longer and increase the risk of errors and denials.
- How can software improve ABA billing?
Modern billing software checks codes, verifies authorizations, and tracks claims automatically. This reduces manual errors before you submit, meaning fewer denials and faster payment cycles.
References
ABA Coding Coalition. (2022). Model coverage policy for adaptive behavior services. In ABA Coding Coalition. https://abacodes.org/model-coverage-policy-for-aba-01-25-2022/
ABA Coding Coalition. (2024, November 7). CMS finalizes 2025 Medicare physician fee schedule. https://abacodes.org/cms-finalizes-2025-medicare-physician-fee-schedule/
ABA Coding Coalition. (2025). Billing codes. https://abacodes.org/codes/
American Medical Association. (2025, September 10). The CPT® code process. https://www.ama-assn.org/about/cpt-editorial-panel/cpt-code-process
American Medical Association. (2025, October 20). CPT®. https://www.ama-assn.org/practice-management/cpt
Centers for Medicare & Medicaid Services. (2025a). Medicare physician fee schedule. https://www.cms.gov/medicare/payment/fee-schedules/physician
Centers for Medicare & Medicaid Services. (2025b). 10/1 update telehealth FAQ calendar year 2025. In cms.gov. https://www.cms.gov/files/document/telehealth-faq-updated-10-15-2025.pdf
