Key takeaways
- Most behavioral health denials come from a few preventable errors: wrong time-based CPT code, missing authorization, eligibility gaps and telehealth coding.
- Psychotherapy codes are time-based. Document actual start and stop times or total face-to-face time for every session.
- Telehealth rules differ by payer. Check place of service codes and modifiers for each plan, not just Medicare.
- A monthly denial review by reason code shows which mistakes cost your practice the most.
Behavioral health medical billing is different from most medical billing: codes are time-based, many plans carve out mental health benefits to separate administrators, prior authorization is common, and telehealth rules vary by payer. Small errors repeat across every session, so one mistake can affect hundreds of claims.
Here are the 12 behavioral health billing mistakes we see most often, why they cause denials or underpayments, and how to fix each one. Coding guidance here is general; always check current CPT guidance and each payer’s policies.
Mistake 1: Choosing the Wrong Psychotherapy Time Code
Individual psychotherapy codes are based on time spent with the patient: 90832 for 30 minutes (16 to 37 minutes), 90834 for 45 minutes (38 to 52 minutes) and 90837 for 60 minutes (53 minutes or more). Billing 90837 for a 50-minute session, or rounding up by habit, invites denials and audit risk. Bill the code that matches the documented time.
Mistake 2: Not Documenting Session Times
Because the codes are time-based, the note must show the time spent in psychotherapy, either start and stop times or total minutes, depending on payer requirements. A note that says only “session completed” will not support the code in an audit.
Mistake 3: Skipping Eligibility and Benefits Checks
Many health plans carve out behavioral health benefits to a separate administrator, with different claim addresses, networks and authorization rules. Verify behavioral health benefits specifically, not just medical coverage, before the first visit and at regular intervals. Our insurance verification service checks this for every new patient.
Mistake 4: Missing Prior Authorization or Visit Limits
Some plans require authorization for ongoing therapy, psychological testing or intensive services, or limit the number of visits. Track authorizations with their approved visit counts and end dates, and request extensions before they expire. See our prior authorization service.
Mistake 5: Incorrect Telehealth Coding
Telehealth claims usually need the right place of service code (for example 02 or 10, depending on where the patient is) and sometimes a modifier such as 95. Medicare, Medicaid and commercial plans do not all follow the same rules, and rules have changed several times in recent years. Keep a payer-by-payer telehealth grid and update it.
Mistake 6: Misusing Add-On Codes
Add-on codes such as 90785 (interactive complexity) and the psychotherapy add-ons used with an E/M visit (90833, 90836, 90838) can only be billed with an eligible primary code and when documentation supports them. Using 90785 routinely without documenting the specific complicating factor is a common audit finding.
Mistake 7: Billing Family Therapy Incorrectly
Family psychotherapy without the patient present (90846) and with the patient present (90847) are separate codes. Some plans do not cover 90846, and documentation must show the session focused on the patient’s treatment.
Mistake 8: Wrong Diagnosis Codes or Missing Specificity
Use specific ICD-10-CM codes that match the documentation and support medical necessity. Unspecified codes, outdated codes or diagnoses not listed in the treatment plan can cause denials.
Mistake 9: Credentialing and Rendering Provider Errors
Billing under the wrong rendering provider, billing for a provider not yet credentialed with the plan, or using incorrect taxonomy codes all lead to denials. Supervision rules for associate-level clinicians vary by payer and must be followed exactly. See our guide on getting credentialed with insurance companies.
Mistake 10: Missing Treatment Plans and Progress Notes
Many payers expect a current treatment plan with measurable goals and progress notes that tie each session to that plan. Missing or outdated plans are a common reason claims fail medical necessity reviews.
Mistake 11: Not Following Up on Denials
Denied or unpaid claims often sit untouched because the team is busy with new sessions. Every payer has timely filing and appeal deadlines. Work denials weekly, starting with the highest-value claims and the oldest dates.
Mistake 12: No Reporting by Denial Reason
Without a monthly report showing denials by reason code and payer, the same mistake repeats. Track clean claim rate, denial rate, days in A/R and collections per session, and fix the top reasons at the source.
From Our Experience with Florida Practices
In the behavioral health practices we work with, the biggest wins usually come from front-end fixes: verifying carved-out benefits, tracking authorizations and agreeing a clear rule for documenting session time. Those three steps prevent more denials than any amount of appeals work afterwards.
A Simple Monthly Billing Checklist for Behavioral Health Practices
- Re-verify eligibility and behavioral health benefits for all active patients, especially after plan changes in January.
- Review open authorizations: visits used, visits left and end dates.
- Audit a sample of notes against the codes billed, checking session time and add-on codes.
- Update your telehealth grid for any payer policy changes.
- Run a denial report by reason and payer, and fix the top three causes.
- Check A/R over 60 days and follow up before timely filing limits pass.
- Confirm credentialing and CAQH attestations are current for every clinician.
Following this checklist every month keeps small errors from growing into large write-offs, and gives clinicians confidence that sessions they deliver are paid correctly.
How Medihike Can Help
Want this done for your practice? These services put the ideas in this article into practice:
Related
- Behavioral Health Billing Services
- Prior Authorization Services
- Medical Coding Services
- All Medical Billing Services
Frequently Asked Questions
How do you bill for therapy sessions?
Verify behavioral health benefits and any authorization, document the session including time spent in psychotherapy, choose the CPT code that matches the documented time, add the correct diagnosis, place of service and modifiers, then submit the claim to the right payer or behavioral health administrator.
What CPT code is used for psychotherapy?
Common individual psychotherapy codes are 90832 (30 minutes), 90834 (45 minutes) and 90837 (60 minutes). The initial diagnostic evaluation is usually 90791, or 90792 when medical services are included.
Can you bill telehealth for mental health?
Yes, most payers cover telehealth mental health services, but the place of service codes, modifiers and eligibility rules differ by payer. Check each plan’s current telehealth policy.
What is the 8-minute rule in behavioral health?
The 8-minute rule applies to timed therapy codes billed in units, such as physical therapy. Psychotherapy codes use their own time ranges, for example 16 to 37 minutes for 90832.
Why are behavioral health claims denied?
Common reasons include eligibility or carve-out errors, missing authorization, time not supporting the code, telehealth coding errors, credentialing problems and missing treatment plans.
Should I outsource behavioral health billing?
Outsourcing makes sense when denials or unpaid claims are growing, or when clinicians spend time on billing instead of patients. Choose a team with behavioral health experience.
Sources
This article is general information for practice owners, not legal, tax or clinical advice. Rules and payer policies change; confirm details with the relevant authority before acting.