An ABA Network Was Using the Wrong CPT Codes for 18 Months. $312,000 in Denials. Two Code Changes Fixed It.
Table of Contents
THE SITUATION
This ABA network had grown from 2 to 7 clinic locations between 2021 and 2024. Billing had scaled alongside growth but the CPT code set hadn’t been reviewed since 2020.
A new billing director joined in early 2024 and started pulling denial trend reports within her first week.
The pattern was immediate: 97% of denials were on three specific CPT codes.
Codes that, when she looked them up, showed a note in CentralReach’s code library: ‘Legacy code use 97153–97158 effective 2019.’
WHAT WAS ACTUALLY WRONG
97001, 97002, and 96150 still in active billing templates:
The 2019 AMA CPT restructuring replaced legacy ABA codes (97001, 97002, 96150) with the new H-code and 97xxx series. CentralReach had flagged this in its system. The billing templates had never been updated. All three legacy codes were still generated on claims.
Tricare has a separate ABA code set not aligned with commercial payers:
TRICARE uses H2019 and H0031 for ABA services not the 97153–97158 series used by commercial payers. The network was billing TRICARE with commercial codes. Every TRICARE ABA claim had been denied since day one.
No billing code audit had been conducted since 2020:
The network had grown from 2 to 7 locations. No one had audited the CentralReach billing templates against current payer requirements. The code errors were scaling with the clinic count.
WHAT WE DID
Week 1: Pulled the complete list of active billing codes from CentralReach across all 7 locations. Identified all legacy codes still in templates. Updated all templates to current 97153–97158 series with correct modifier mapping by payer.
Week 2: Audited TRICARE requirements. Rebuilt TRICARE-specific billing templates with H2019 and H0031. Submitted test claims before going live.
Weeks 3–6: Resubmitted 18 months of legacy-code denials still within filing windows 97153–97158 corrections for commercial payers, H-code corrections for TRICARE.
Week 7 onward: Implemented a quarterly billing code audit code templates reviewed against each payer’s current fee schedule every 90 days.
THE RESULTS
| Metric | Before | After |
|---|---|---|
| Legacy Code Denial Rate | 97% | 4% |
| Revenue Recovered | — | $312,000 |
| TRICARE Claim Acceptance | 0% | 91% |
| Billing Templates Corrected | All 7 locations outdated | All current |
| Code Audit Process | None | Quarterly, scheduled |
WHAT THIS MEANS FOR YOUR PRACTICE
ABA CPT code changes in 2019 were well-publicized but not every billing team updated their templates, and not every EHR catches legacy codes automatically. If your ABA organization hasn’t had a billing code audit against current payer fee schedules in the last 12 months, there’s a meaningful chance your billing codes payers haven’t accepted in years.