Behavioral Health Billing Resource Center
Behavioral health billing has unique challenges — session limits, telehealth rules, parity law compliance, and complex modifier requirements. This resource center provides the reference guides you need to reduce denials and improve collections.
Quick Answer
Behavioral health billing involves specialized coding and billing rules for mental health and substance use disorder services. Key considerations include MHPAEA parity requirements, telehealth billing modifiers (GT/95), levels of care (inpatient, IOP, outpatient), and behavioral health-specific denial codes. Behavioral health claims have higher denial rates than medical claims due to complex authorization requirements.
Key Takeaways
Behavioral health has higher denial rates than general medical billing.
MHPAEA (Mental Health Parity and Addiction Equity Act) requires equal coverage for mental health.
Telehealth modifiers (GT, 95) are essential for virtual sessions.
Prior authorization is frequently required for behavioral health services.
Levels of care (inpatient, residential, IOP, outpatient) affect coding and billing.
Step-by-Step
Verify behavioral health benefits
Confirm mental health coverage, session limits, and prior auth requirements specific to behavioral health.
Use correct CPT codes
Use 90832–90837 for psychotherapy, 90834 for 45-min sessions, and appropriate add-on codes for additional services.
Apply telehealth modifiers when applicable
Use modifier GT or 95 for telehealth sessions. Verify payer-specific telehealth requirements.
Check prior auth for higher levels of care
IOP, residential, and inpatient behavioral health typically require prior authorization.
Common Mistakes
Not verifying behavioral health-specific benefits — mental health coverage differs from medical.
Forgetting telehealth modifiers — causes denials for virtual sessions.
Not checking session limits — behavioral health plans often have annual visit caps.
Using incorrect time-based codes — psychotherapy codes are time-specific.
FAQ
Related Resources
Top Denials
Common Behavioral Health Denial Codes
| Code | Description | Common Cause | Resolution |
|---|---|---|---|
| CO-197 | Authorization absent | No prior auth for therapy sessions | Obtain retro auth or appeal with medical necessity |
| CO-50 | Non-covered services | Service not covered under plan | Verify benefits; appeal with medical necessity |
| CO-16 | Claim/service lacks information | Missing modifier or referral | Correct claim and resubmit |
| CO-97 | Service bundled | Psychotherapy included in E/M code | Remove bundled code; resubmit |
| CO-151 | Frequency limit exceeded | More sessions than authorized | Appeal with medical necessity for additional sessions |
| CO-29 | Timely filing | Submitted after payer deadline | Appeal with proof of timely submission |
Modifier Quick Reference
Essential Behavioral Health Modifiers
| Modifier | Description | Use Case |
|---|---|---|
| -25 | Significant, separately identifiable E/M | E/M with psychotherapy on same day |
| -27 | Multiple encounters on same day | Multiple separate visits same date |
| -59 | Distinct procedural service | Separate services not normally bundled |
| -95 | Synchronous telemedicine | Video-based therapy sessions |
| -GT | Telehealth service (legacy) | Some Medicaid telehealth |
| -HO | Doctoral-level clinician | Some payer requirements for psychologists |
| -HN | Master's-level clinician | Some payer requirements for LCSWs/LPCs |
Frequently Asked Questions
Behavioral Health Billing FAQ
How is behavioral health billing different from medical billing?
Behavioral health billing differs from medical billing in several ways: (1) session limits — many plans cap the number of therapy sessions per year; (2) prior authorization is often required after a set number of visits; (3) telehealth rules are more complex and payer-specific for behavioral health; (4) modifier requirements differ — modifiers like -HO, -HN, -AJ identify the clinician's license type; (5) mental health parity laws require coverage at the same level as medical benefits; and (6) different CPT code sets are used (90832–90853 for psychotherapy, 90791–90792 for diagnostic evaluation).
What are the most common behavioral health CPT codes?
The primary behavioral health CPT codes are: 90791 (Psychiatric diagnostic evaluation, 60-90 min), 90792 (Psychiatric diagnostic evaluation with medical services), 90832 (Psychotherapy, 30 min), 90834 (Psychotherapy, 45 min), 90837 (Psychotherapy, 60 min), 90836 (Psychotherapy + E/M, 45 min), 90838 (Psychotherapy + E/M, 60 min), 90839 (Psychotherapy for crisis, first 60 min), 90840 (Crisis psychotherapy, additional 30 min), 90853 (Group psychotherapy), 90845 (Medical psychoanalysis), 90846 (Family psychotherapy without patient), 90847 (Family psychotherapy with patient), 90849 (Multiple-family group psychotherapy), 90853 (Group psychotherapy).
What is modifier -25 and when is it used in behavioral health?
Modifier -25 is used when a significant, separately identifiable evaluation and management (E/M) service is performed on the same day as psychotherapy. For example, a psychiatrist who provides medication management (E/M) and psychotherapy during the same session would bill both an E/M code with modifier -25 and the appropriate psychotherapy code (90832, 90834, or 90837). Without the -25 modifier, the E/M service would be bundled into the psychotherapy code and not separately reimbursed. Documentation must support both services.
What is mental health parity and how does it affect billing?
Mental Health Parity and Addiction Equity Act (MHPAEA) requires that insurance plans covering mental health and substance use disorder services provide those benefits at parity with medical/surgical benefits. This means no more restrictive financial requirements (copays, deductibles) or treatment limitations (session limits, prior auth requirements) than those applied to medical/surgical benefits. If a payer denies behavioral health services for reasons that would not apply to equivalent medical services, a parity appeal may be warranted. Violations can also be reported to state insurance commissioners.
How does telehealth billing work for behavioral health?
Telehealth billing for behavioral health requires attention to several factors: (1) use the correct telehealth modifier — -95 (synchronous audio-video) is most common; some Medicaid plans still use -GT; (2) verify the payer covers telehealth for the specific service code; (3) check if the payer requires a specific place of service code (02 for telehealth, 10 for home); (4) audio-only telehealth (phone) uses different codes and has stricter coverage rules post-PHE; (5) state laws and payer policies change frequently — verify current rules before each session. Medicare covers telehealth psychotherapy but with specific requirements.