Assessment vs. Treatment: The Core Distinction
ABA billing has a clear distinction between assessment activities (evaluating and measuring behavior) and treatment activities (implementing interventions to change behavior). Using the correct code is essential to avoid denials and compliance issues.
Assessment Codes (97151 / 97152)
97151 — Behavior Identification Assessment
Used when a BCBA is conducting structured assessment activities, including:
- Functional behavior assessment (FBA)
- VB-MAPP, ABLLS-R, CARS-2, or other standardized assessments
- Preference assessments
- Report writing and treatment plan development
97152 — Supporting Assessment
Used when a technician (RBT) is assisting the BCBA with assessment data collection.
Treatment Codes (97153 / 97155)
97153 — RBT implementing the behavior plan during direct therapy sessions.
97155 — BCBA providing direct treatment AND modifying the protocol during the session.
Can You Bill Assessment and Treatment on the Same Day?
Yes — but you must use modifier 59 to unbundle them, and your documentation must clearly show that distinct services occurred. Example: BCBA conducts a re-assessment in the morning (97151), then provides direct treatment in the afternoon (97155). Document separately and consider separate session notes.
Common Mistakes
- Billing 97153 for assessment activities (wrong code — use 97151)
- Forgetting that 97151 requires a BCBA as the rendering provider
- Not documenting what made the session an "assessment" vs. "treatment"