TOP 6 CPT 97153 Billing Mistakes Costing Your ABA Practice

As an ABA practice owner or billing manager, you're likely familiar with the critical importance of accurate billing and claims management. Yet one code, CPT 97153, continues to generate denials, recoupments, and compliance issues across the ABA industry.

For most ABA practices, 97153 represents one of the highest-revenue services because it covers the majority of direct, one-on-one therapy sessions. But despite how commonly it’s used, it is also one of the most frequently mishandled during billing and submission.

What is CPT Code 97153?

The 97153 CPT code description refers to adaptive behavior treatment by protocol, delivered one-on-one by a technician, under the supervision of a physician or other qualified healthcare professional, billed per 15 minutes, and performed according to an established protocol. For a detailed breakdown of supervision requirements and documentation guidelines, read our complete guide to CPT Code 97153.

When and Where to Use CPT Code 97153

Use cpt 97153 when all of the following are true:

• The service is direct treatment with the client (not supervision, not caregiver training, not assessment)

• It’s one patient and face-to-face

• The session follows the current treatment protocol

• The time is captured accurately to support units

• You have prior authorization when required and you’re within approved limits

CPT code 97153 can be billed in a clinic, patient’s home, school, or community setting, based on payer rules and authorization, with proper documentation meeting code requirements. Most commercial plans and Medicaid programs recognize 97153 ABA code as a core direct‑treatment code. However, 97153 CPT code reimbursement depends on your units, modifiers, documentation, and authorization all lining up with the code definition.

Key 97153 Billing Mistakes to Avoid

Below are the top cpt 97153 errors that silently drain revenue or audit risk and how to fix them.

Mistake 1: Incorrect Unit Calculation in 97153

The 97153 cpt code is billed in 15-minute increments. This means your billed units must match the actual minutes delivered to the patient. 

Why This Happens

• Using scheduled time instead of rendered time

• Rounding up units to be safe

• Overlooking that many payers apply the “8-minute rule” for time-based codes

• Under this rule, 1 unit equals 8–22 minutes, 2 units equal 23–37 minutes, and so on.

Even small mismatches between minutes and billed units can trigger denials or repayment requests, especially if an auditor compares notes to claims.

Example:

The session was scheduled for 3:00–4:00 but started at 3:08 and ended 3:56 (48 minutes rendered). If you bill 4 units automatically, you’re exposed. Your billing should reflect the minutes actually delivered.

How to Solve It

• Require therapists to record exact start and end times for every session.

• Subtract non-billable gaps such as late arrivals, unpaid breaks, or time not covered by the payer.

• Use a simple unit calculator rule in your billing workflow so staff are not estimating units.

• Add a quick same-day cross-check before claims are submitted, especially for longer or higher-unit sessions.

If your team still struggles with unit math, this quick 8-Minute Rule Cheat Sheet can help clarify calculations.

Mistake 2: Overlapping Services Billed at the Same Time

Overlapping services happen when two time-based ABA codes are billed for the same patient during the same time block. 

Why it happens

This usually starts with scheduling. Two providers may work with the same client close together, and the time blocks end up overlapping on paper. Even if both staff were active, payers see duplicate time.

Unless a payer clearly allows overlapping services with strong documentation showing separate providers and distinct activities, the claim will likely be denied.

Example:

RBT session 2:00–4:00 (97153). BCBA joins 3:00–3:30 for protocol modification. If you bill 97155 for 3:00–3:30 and still bill the RBT as if uninterrupted, you’ve created overlapping time. Clean fix: adjust the RBT minutes or clearly separate services per payer rules.

How to Solve

• Set a hard operational rule: one patient, one time-based ABA code at a time

• Separate the time blocks clearly

• Document different goals and activities

• List the correct rendering provider for each block

Mistake 3: Missing or Exceeding Authorized Units

This mistake occurs when CPT code 97153 is billed without a valid prior authorization or when services exceed the approved units or date range.

Why it happens

Claims fail when sessions start before auth is active, continue after expiration, use the wrong rendering provider or location, or exceed approved units. 

Even with perfect prior auth, payers still deny incorrectly. A U.S. HHS OIG review found 13% should have been approved.

How to Solve

• Verify authorization before the first 97153 session is rendered

• Track remaining units weekly, not monthly

• Set alerts at 70–80% utilization so you can start reauth early

• Match the auth details to the billing: dates, place of service, provider credentials, and rendering type

If you're looking for prior authorization, check out our guide.

Mistake 4: Incorrect or Missing Modifiers

This mistake happens when cpt code 97153 is submitted without the correct modifier required by the payer.

Why it happens

Incorrect or missing modifiers happen when the required code, like HM for RBT or 95 for telehealth, is not added correctly to CPT 97153. 

Since modifier rules vary by payer and state, using the wrong one or leaving it out can cause a claim denial or wrong payment.

How to Solve

• Build a payer-by-payer modifier matrix specifically for 97153 aba code

• Train staff to document delivery method accurately (in-person vs telehealth)

• Add claim edits that block submission if required modifiers are absent

• Recheck modifier rules any time payer policy updates (especially for telehealth)

Mistake 5: Documentation Shortfalls

To defend a 97153 claim, your note must prove that direct, 1:1 protocol‑based treatment occurred for the time billed. A guide on ABA therapy documentation explains how to structure stronger session notes

Why it happens

Denials and recoupments often stem from:

• Missing or vague start/end times

• Minimal or subjective data (client did well vs measurable data)

• No clear link to treatment plan goals

• Missing signatures or credentials

Even if the service was delivered properly, weak notes make cpt 97153 hard to defend.

How to Solve

Use a structured note format for CPT code 97153 that requires:

• Start time, end time, total minutes, units billed

• Goals addressed and measurable data

• Behaviors targeted and interventions used

• Place of service and delivery method

• Rendering staff name, credential, and signature

Audit a small sample of notes weekly. Correct small issues early before they become billing patterns.

Mistake 6: Scope of Service Errors

This mistake happens when 97153 is used for services that do not match the official 97153 CPT code description.

Why it happens

Scope-of-service errors occur when CPT 97153 is billed for activities that are not direct treatment, such as parent training, assessment, travel time, or report writing. 

Since 97153 is only for direct technician implementation with the patient, billing outside that scope can lead to claim denials and compliance issues.

Example:

If the RBT spends 15 minutes updating materials while the child is not engaged in direct treatment, those minutes may not belong in the billed time.

How to Solve

• Train everyone on a simple rule: if it’s not direct one-on-one protocol implementation with the patient, it’s not 97153

• Create a cheat sheet that maps common activities to the correct code or to non-billable time

• Require the note to state that the session followed the current plan/protocol and list the specific targets implemented

FAQ

1. How many units can you bill for CPT code 97153?

Units depend on actual minutes delivered. Since CPT code 97153 is billed in 15-minute increments, follow payer time rules and bill only for the rendered time.

2. What is the 97153 CPT code reimbursement?

Reimbursement varies by payer contract, credentialing status, and place of service. The most reliable way to predict it is to check your payer fee schedule/contract and confirm whether modifiers or location affect the rate.

3. Can 97153 and 97156 be billed together?

Yes, but not at the same time. 97153 is direct technician treatment, and 97156 is caregiver training. Both can be billed on the same day only in separate, non-overlapping time blocks with clear documentation, subject to payer policy.