- Key Takeaways
- CPT code 90791 reports a psychiatric diagnostic evaluation without medical services, the comprehensive intake assessment that opens a course of behavioral health treatment.
- Unlike the psychotherapy codes, 90791 is not time-based; it is defined by a complete assessment, so the note must show a thorough evaluation rather than a session length.
- Most payers cover 90791 only once per episode of care, roughly every six to twelve months, so repeat or duplicate intakes are a leading denial.
- If medication is prescribed or managed during the evaluation, 90792 applies instead of 90791, and miscoding this is one of the most common psychiatry billing errors.
- Non-prescribers bill 90791, and since 2024 marriage and family therapists and mental health counselors can report it under Medicare, though 90792 requires prescriptive authority.
In 2024, 23.4 percent of US adults, roughly 61.5 million people, had a mental illness in the past year, according to SAMHSA’s National Survey on Drug Use and Health. Nearly every one of them who enters treatment starts the same way: with an intake evaluation. That evaluation is CPT code 90791. It sits at the front door of behavioral health, which is exactly why getting it right matters, and why it behaves differently from the therapy codes billed after it. 90791 is not time-based, and its most common denials are structural, tied to how often it can be billed and who bills it, not to minutes on a clock.
Current as of 2026. Always verify code status and payment with your specific payer, since policies change.
What 90791 is: the intake, not the therapy
90791 is a psychiatric diagnostic evaluation without medical services. It is the comprehensive initial assessment that opens a course of care: gathering the psychiatric and psychosocial history, performing a mental status examination, arriving at a diagnosis, and setting the initial treatment plan. It is billed by non-prescribing clinicians, including licensed clinical social workers, licensed professional counselors, marriage and family therapists, mental health counselors, and psychologists.
The word to focus on is “without medical services.” The moment medication enters the evaluation, whether prescribing, adjusting, or managing it, the correct code is 90792, not 90791. More on that boundary below.
Why 90791 is not a time-based code
This is the point most guides skip, and it changes how you document. The individual psychotherapy codes we cover in our guides to CPT code 90834 and CPT code 90837 are chosen by documented face-to-face minutes. 90791 is not. It has no minute threshold. It is defined by the completeness of the assessment.
That means a 90791 note is judged on content, not duration. A payer wants to see a thorough diagnostic evaluation, the history, the mental status exam, the clinical formulation, the diagnosis, and the plan, not a start and stop time. Practices that carry time-based documentation habits over from therapy codes often under-document the assessment itself, which is what puts the claim at risk. Document the evaluation fully and the time takes care of itself.
How often you can bill 90791
Frequency is where most 90791 denials come from. Most payers cover the code once per episode of care, commonly once every six months to one year per provider. It is appropriately billed again when a genuinely new treatment episode begins, when the patient’s condition changes significantly enough to warrant a fresh evaluation, or when a new provider takes over care.
Two situations cause repeat denials. The first is re-billing 90791 for the same ongoing episode, treating a routine reassessment as a new intake. The second is a coordination gap: when a patient starts with both a therapist and a prescriber, each may bill their own evaluation, but two intakes from the same discipline, or uncoordinated duplicate submissions, will deny. The fix is to know, before the claim goes out, whether an intake has already been billed for this patient and episode. Our complete guide to denial management covers building that check into the workflow.
- Neolytix • Medical Billing
Medical Billing
90791 vs 90792
The distinction is simple and consequential, and it usually follows the provider type:
| 90791 | 90792 |
Service | Diagnostic evaluation without medical services | Diagnostic evaluation with medical services |
Medication involved | No | Yes (prescribing, adjusting, or managing) |
Typical provider | Non-prescribers (LCSW, LPC, LMFT, LMHC, psychologists) | Prescribers (psychiatrists, PMHNPs) |
Reimbursement | Lower | Higher |
Billing 90791 when medication was actually managed is one of the most commonly miscoded psychiatry encounters and a real audit risk. Our psychiatry billing and coding guide covers that boundary and its documentation in depth.
Documentation requirements for 90791
A defensible 90791 note should include:
- The presenting problem and relevant psychiatric, medical, family, and social history
- A mental status examination
- A diagnostic formulation and the resulting diagnosis, with an ICD-10-CM code that supports medical necessity
- Initial treatment recommendations or plan
- Confirmation that no medical services (medication management) were part of the evaluation, since those belong to 90792
The through-line: show a complete assessment. A brief note that reads like a therapy progress note will not support an intake code.
Common billing errors to avoid
- Billing 90791 when medication was managed. That encounter is 90792. This is the single most common miscoding error.
- Re-billing it for the same episode. A routine reassessment inside an ongoing episode is not a new intake.
- Uncoordinated duplicate intakes. Two evaluations from the same provider or discipline for one episode will deny.
- Under-documenting the assessment. Because 90791 is not time-based, the note must prove a thorough evaluation, not a session length.
- Missing the telehealth modifier. A video intake needs modifier 95 and the correct place of service.
- Wrong diagnosis linkage. The ICD-10-CM code must establish medical necessity for the evaluation.
Who can bill 90791, and telehealth
90791 is billed by non-prescribing clinicians. Since January 1, 2024, marriage and family therapists and mental health counselors have been eligible Medicare providers alongside the clinicians who could already bill it. Prescribers who provide medical services during the evaluation use 90792 instead. Every provider must be enrolled and credentialed with the payer before billing, which our therapist credentialing guide walks through.
The interactive complexity add-on (90785) may be reported with 90791 when specific communication barriers are documented. For telehealth, 90791 is billable for a synchronous video evaluation with modifier 95 and the appropriate place of service, subject to each payer’s current rules.
Reimbursement context
90791 is paid under the Medicare Physician Fee Schedule and generally reimburses less than 90792, since 90792 includes medical services. The exact amount varies by provider credential, place of service, and locality, and newly eligible therapist types are often paid at a percentage of the psychologist rate. Treat any single figure as illustrative and confirm the current rate for the specific provider type and setting through the CMS Physician Fee Schedule Look-Up Tool, which updates annually.
The bottom line
90791 is the first claim in most behavioral health relationships, and a denied intake stalls everything that follows. Document the full assessment rather than a session length, know your payer’s frequency rule, coordinate when more than one provider is involved, and move to 90792 the moment medication enters the picture. For practices that would rather not track intake rules payer by payer, Neolytix has supported healthcare organizations across the United States for over 14 years, with behavioral health coding review built into its medical billing services so intake claims are clean before they go out.
- Neolytix • Contact Us
Schedule a Consultation
Neolytix partners with healthcare organizations across revenue cycle, credentialing, and administrative operations ,14+ years of expertise and AI-enabled automation to reduce inefficiencies and drive sustainable growth.
This guide reflects Neolytix’s expertise in healthcare revenue cycle management and is intended for educational purposes only. It does not constitute legal or compliance advice. CPT codes and reimbursement rates are periodically updated by the AMA and CMS.
Sources
- Substance Abuse and Mental Health Services Administration. 2024 National Survey on Drug Use and Health, key findings (adult mental illness prevalence). https://www.samhsa.gov/newsroom/press-announcements/20250728/samhsa-releases-annual-national-survey-on-drug-use-and-health
- American Medical Association. CPT diagnostic evaluation codes (90791, 90792). https://www.ama-assn.org/practice-management/cpt
- Centers for Medicare & Medicaid Services. Physician Fee Schedule Look-Up Tool (reimbursement by provider type and locality). https://www.cms.gov/medicare/physician-fee-schedule/search
- Centers for Medicare & Medicaid Services. Marriage and Family Therapists & Mental Health Counselors (2024 Medicare eligibility). https://www.cms.gov/medicare/enrollment-renewal/providers-suppliers/marriage-family-therapists-mental-health-counselors
- AAPC. CPT code 90791 reference. https://www.aapc.com/codes/cpt-codes/90791
Frequently Asked Questions
How often can you bill CPT 90791?
Most payers cover 90791 once per episode of care, commonly every six months to one year per provider. It can be billed again for a new treatment episode, a significant change in condition, or when a new provider begins care. Billing it repeatedly for the same ongoing episode is a frequent denial.
What is the difference between 90791 and 90792?
Both are psychiatric diagnostic evaluations. 90791 is the evaluation without medical services, used by non-prescribers such as therapists and psychologists. 90792 is used when medical services, including medication prescribing or management, are part of the evaluation, and it requires prescriptive authority. Billing 90791 when medication was managed is a common, avoidable error.
Can two providers bill 90791 for the same patient?
Often yes. When a patient begins care with both a therapist and a prescriber, each may bill a 90791 or 90792 for their own evaluation, subject to payer rules. However, two intakes from the same provider or discipline for one episode will usually deny as a duplicate. Coordinate and document distinct evaluations.
Is CPT 90791 time-based?
No. Unlike the psychotherapy codes 90832, 90834, and 90837, 90791 is not defined by time. It is defined by the completeness of the assessment: history, mental status examination, diagnosis, and treatment recommendations. There is no minimum minute threshold, though the note must show a thorough diagnostic evaluation to support the code.
Can 90791 be billed for telehealth?
Yes. 90791 can be performed and billed via telehealth. Append modifier 95 for a synchronous audio-video evaluation and use the correct telehealth place of service. Medicare continues behavioral health telehealth flexibilities in 2026, and audio-only may be permitted in some cases. Confirm each payer’s current policy before submitting the claim.
