CPT Code 90791: Psychiatric Diagnostic Evaluation
Reviewed against AMA CPT and CMS guidance. See sources.
What is CPT 90791?
CPT 90791 is the psychiatric diagnostic evaluation without medical services: an integrated biopsychosocial assessment with history, mental status, and diagnosis, usually done at intake. CPT gives it no time range, so it is billed once per evaluation regardless of length. Therapists, counselors, social workers, and psychologists use it; prescribers adding medical services use 90792.
An integrated biopsychosocial assessment including history, mental status exam, and diagnosis. This is a diagnostic evaluation performed without medical services (no E/M component). Used for initial intake assessments by therapists, counselors, psychologists, and social workers.
Time Requirements
Not a timed code. CPT sets no minimum or maximum duration, so 90791 is reported once for the evaluation whether it takes 45 or 90 minutes. Record the actual time anyway; some payers expect it.
Modifiers
| Code | Description |
|---|---|
| 95 | Synchronous audio-video telehealth. Many payers also require a telehealth place of service code (02 or 10). |
| 93 | Synchronous audio-only service, where the payer allows audio-only care. |
| GT | Interactive audio and video telecommunication (legacy; most payers now use 95). |
Billing a session by video or phone? See telehealth modifiers 95, 93, GT and POS 02 vs 10.
When to Use
- Initial intake evaluation for a new client
- Comprehensive re-evaluation when the diagnosis is being reconsidered
- A new episode of care after a long gap in treatment, when the payer allows a repeat evaluation
- When building a new treatment plan from a full diagnostic workup
When Not to Use
- Routine follow-up therapy sessions: use 90832, 90834, or 90837
- On the same day as psychotherapy (90832 to 90838) or crisis psychotherapy (90839, 90840) by the same clinician
- On the same day as an E/M service by the same clinician
- When medical services such as medication evaluation are part of the visit: use 90792
- Standalone screening questionnaires: use 96127 per instrument
What to Document for CPT 90791
- Reason for referral and presenting problem
- Psychiatric, medical, substance use, family, and social history
- Mental status examination
- Risk assessment for suicide, self-harm, and harm to others
- Diagnostic impressions with ICD-10-CM codes
- Initial recommendations or treatment plan, and who provided information (client, parent, other informants)
Common Denial Reasons
- Billed more often than the payer allows without a documented reason for re-evaluation
- Missing core elements: history, mental status exam, or diagnostic formulation
- Billed with a psychotherapy or E/M code for the same client, clinician, and date
- Missing or invalid diagnosis code on the claim
Payer Notes
Many payers allow one 90791 per client per clinician at the start of care, with another only for a new episode, a significant clinical change, or a long gap. CPT allows 90791 to be reported more than once when separate evaluations are done with the client and with other informants, but payers often limit this, and Medicare generally allows one per day. Prior authorization is uncommon, but check the plan.
ICD-10 diagnosis codes
Every claim pairs the CPT code with the diagnosis the clinician documented. See the mental health ICD-10 code reference or a condition guide:
Related Codes
Frequently Asked Questions
Can I bill 90791 and a therapy code on the same day?
No, not for the same clinician and client. CPT does not allow 90791 on the same date as psychotherapy (90832 to 90838), crisis psychotherapy, or an E/M service by the same clinician. If the intake runs long, bill 90791 alone and start psychotherapy codes at the next visit.
How is 90791 different from 90792?
90791 is a diagnostic evaluation without medical services. 90792 adds medical services such as medication evaluation or physical examination, so it is limited to physicians and other clinicians who can provide medical services. Therapists, counselors, social workers, and psychologists use 90791.
How long does a 90791 need to be?
CPT sets no time requirement. A thorough intake often takes 45 to 90 minutes, but the code is chosen by the content of the evaluation, not the clock. Record the actual time and make sure history, mental status, risk, and diagnosis are all documented.
How often can 90791 be billed?
Payer rules vary. Many allow one per client per clinician per episode of care, with another for a new episode, a significant change, or a long gap in treatment. Check the payer policy before billing a second evaluation.
Can 90791 be done by telehealth?
Many payers cover it by audio-video telehealth, usually with modifier 95 and a telehealth place of service code (02 or 10). Some allow audio-only care with modifier 93. Telehealth rules change often, so confirm with each payer.
Sources: American Medical Association (AMA), CPT Professional codebook: code descriptors, psychotherapy time rules, and add-on code guidance. Centers for Medicare & Medicaid Services (CMS): Medicare Physician Fee Schedule and National Correct Coding Initiative (NCCI) policy.
- AMA: CPT overview
- CMS: National Correct Coding Initiative (NCCI) edits
- CMS Medicare Coverage Database: Billing and Coding, Psychiatry and Psychology Services (A57480)
- CMS: Physician Fee Schedule relative value files
- CMS MLN901705: Telehealth and Remote Monitoring (PDF)
Payer rules vary. Confirm coverage, time, modifier, and documentation rules with each payer before billing. This page is general education, not billing or legal advice.
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