90791 CPT Code: Psychiatric Diagnostic Evaluation Guide

The 90791 CPT code reports a psychiatric diagnostic evaluation — the initial behavioral-health intake that establishes a diagnosis and treatment plan without medical (E/M) services. It is the assessment a therapist, psychologist, or clinical social worker bills at the start of care: history, mental status, and diagnostic formulation. Because it opens the episode and is paid at a higher rate than a routine session, payers watch how often 90791 is billed.

What is the 90791 CPT code? 90791 is the Current Procedural Terminology code for a psychiatric diagnostic evaluation without medical services — an integrated biopsychosocial assessment that establishes a diagnosis and initial treatment plan.

Undeny's Take

90791 is where intake revenue quietly leaks, almost always over a frequency rule. Most payers allow one 90791 per patient per episode of care, per provider — bill a second one when a client returns months later and it pays; bill it again too soon, or have two clinicians in the same practice each bill it, and it denies as a duplicate. The practical move is a simple intake log: who evaluated whom and when. For genuine re-evaluations after a real gap, document the clinical reason and the date math so the repeat 90791 survives review.

What the 90791 Code Covers

90791 covers an integrated biopsychosocial assessment, including history, mental status examination, and a diagnostic formulation, performed without the medical evaluation-and-management component. When a psychiatrist or other prescriber performs an evaluation that includes medical services, code 90792 applies instead. 90791 is used by both prescribing and non-prescribing clinicians for the diagnostic intake.

Frequency, Units, and Reimbursement

90791 is reported once per evaluation as a single unit; it is not a timed, 15-minute code. Most plans limit it to one per episode of care per provider, with re-evaluations allowed after a defined interval or a significant change in condition. Reimbursement follows each payer's fee schedule — Medicare from the code's RVUs on the Physician Fee Schedule, commercial plans by contract. Use the CPT estimator or your contract for a working number.

Modifiers and Add-Ons

95 — synchronous telehealth intake, where the payer permits remote evaluation.
90785 — interactive complexity add-on when communication factors complicate the assessment.
Some Medicaid and managed-care plans require program or discipline modifiers.

Common 90791 Denials

Duplicate or frequency denial when billed more than once per episode or by multiple clinicians.
Same-day conflict with a psychotherapy or E/M code the payer does not allow together.
Missing authorization for plans that require it before the intake.
Telehealth modifier or place-of-service mismatch.

Related Codes

90791 begins the care episode that the therapy codes continue. 90837 and 90834 are the 60- and 45-minute psychotherapy sessions that follow the evaluation. Browse the full set under CPT codes.

Frequently Asked Questions

What does 90791 cover?

90791 covers a psychiatric diagnostic evaluation — an integrated biopsychosocial intake that establishes a diagnosis and treatment plan without medical evaluation-and-management services. It is the standard initial assessment in behavioral-health care.

How often can you bill 90791?

Most payers allow one 90791 per patient per episode of care, per provider. A repeat is generally permitted after a defined interval or a significant change in condition, with documentation supporting the re-evaluation.

What is the difference between 90791 and 90792?

90791 is the diagnostic evaluation without medical services; 90792 is the evaluation with medical services, billed by prescribers who include an E/M component. Choose based on whether medical services were part of the assessment.

Can 90791 and a therapy code be billed the same day?

Often not for the same provider, because many payers bundle a same-day evaluation and psychotherapy. Check the specific payer's policy before billing both on one date of service.

Informational only — not legal, medical, or billing advice. Always verify against current CPT guidance and your payer policy.

Estimate 90791 reimbursement

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