CPT · Psychotherapy
90791: Psychiatric diagnostic evaluation without medical services
90791 reports an initial diagnostic assessment of a behavioral health patient — history, mental status, and treatment planning — performed without a medical or prescribing component. It is typically the first code billed in an episode of care.
What it covers
The evaluation establishes the diagnosis and treatment plan: presenting problem, psychiatric and relevant medical history, mental status examination, risk assessment, and recommendations. It is reported by clinicians whose scope does not include the medical component, which is what separates it from 90792.
Many payers limit how often it can be reported for the same patient — commonly once per episode of care or once per year — and some require authorization before the intake rather than after.
When to use it
- A new patient's initial diagnostic assessment
- Re-evaluation after a significant gap in treatment, where payer policy allows
- An assessment involving informants where the patient is not the sole source of history
Where the boundary sits
| Compared with | The deciding rule |
|---|---|
| 90792 | 90792 is the equivalent evaluation including medical services, reported by prescribing clinicians. |
| 90837 | The intake evaluation is not a therapy session. Do not report 90837 for the assessment itself. |
Documentation that keeps it paid
- Presenting problem, relevant history, and mental status findings
- Risk assessment, including any safety planning
- The diagnosis reached and the treatment plan that follows from it
Denial & audit triggers
Frequency limit exceeded
Reporting a second evaluation inside the payer's window is a routine denial and is usually not appealable without a documented clinical change.
Missing authorization
Several Medicaid managed care plans require authorization for the intake. Delivering the assessment first makes it unbillable.
Scope mismatch
Billing 90791 under a prescribing clinician who performed medical services, or 90792 under a clinician outside that scope, produces provider-type denials.
How it pairs with other codes
- Not reported with a psychotherapy code for the same session by the same clinician
- Sometimes reported on separate days for a multi-session evaluation, where payer policy allows
Questions we get asked
- How often can 90791 be billed for one patient?
- Payer-specific. Common limits are once per episode of care or once per twelve months. Confirm the plan's rule before scheduling a re-evaluation.
- Can 90791 be delivered via telehealth?
- Widely, yes, with the appropriate modifier and place of service. Audio-only acceptance varies by plan and state.
Reference only, and typical rather than universal: coverage, modifier requirements, and payment vary by payer, plan, state, and provider type. Confirm current payer policy before billing. CPT is a registered trademark of the American Medical Association; official descriptors are not reproduced here.
How does your A/R and denial rate compare?
Free benchmark tool — enter six numbers, see your bands against published industry sources, and download a branded PDF.