No. CPT doesn’t set a time for 90791; you bill it once for the evaluation regardless of length. Document the time anyway, since some payers review long or repeated evaluations.

How often can I bill 90791?

CPT allows it more than once when a new evaluation is needed, but many payers limit it to once per episode of care or once every 6 to 12 months per clinician. Check the payer’s policy before billing a second one.

What is the difference between 90791 and 90792?

90791 is the evaluation without medical services. 90792 adds medical services (such as a physical exam or prescribing) and is billed by physicians and other prescribers.

Can I bill 90791 and 90837 on the same day?

Not by the same clinician for the same client. Bill the intake as 90791 and start psychotherapy codes at the next session.

CPT code reference for therapists

CPT 90791: Psychiatric diagnostic evaluation

90791 is the code for the diagnostic evaluation at the start of care: the intake session where you gather history, assess the client and arrive at a diagnosis and a treatment plan. It covers the assessment only, without medical services such as a physical exam or prescribing.

Psychiatrists, psychiatric nurse practitioners and other prescribers who include medical services use 90792 instead.

Updated October 5, 2026

What it is: Intake / diagnostic assessment, no medical services
Time: Not time-based
Who bills it: Psychologists, LCSWs, LMFTs, LPCCs/LPCs, psychiatrists
Prescriber version: 90792 (with medical services)

When to use 90791

The first session with a new client, when the session is an assessment rather than treatment.
A re-evaluation when a client returns after a long break or their presentation has changed enough to need a new diagnostic assessment.
Interviews with family members or other informants that are part of the assessment, on a separate day from the client’s evaluation.

Time rules

90791 has no time requirement in CPT. Bill it once for the evaluation whether it took 50 minutes or 90.
Some payers publish expected durations or pay for a longer or split evaluation differently; when an evaluation runs across two sessions, check whether the payer wants it billed once or on each date.

What to document

Reason for referral and presenting problem, in the client’s words where possible.
History of the present problem, past psychiatric and treatment history, substance use, medical history and current medications.
Family, social, developmental and educational or work history relevant to the problem.
Mental status examination and a risk assessment (suicide, self-harm, harm to others).
Diagnosis (ICD-10-CM), with the reasoning that supports it.
Initial treatment plan and recommendations: modality, frequency and goals.

Billing rules and common denials

Don’t bill 90791 and a psychotherapy code (90832–90838) for the same client on the same day by the same clinician.
Many payers limit 90791 to once per episode of care, or once every 6 to 12 months per clinician. A second one inside that window is a common denial.
Add-on 90785 (interactive complexity) can go with 90791 when something like a third party, an interpreter or conflicting caregivers made the communication harder.
For telehealth, payers differ: Medicare uses place of service 10 or 02, while many commercial plans want the in-person place of service (usually 11) with modifier 95. Check each payer’s telehealth policy.

Telehealth modifiers

95: Live (synchronous) video visit. The modifier most commercial plans and Medicaid programs ask for.
GT: Older “via interactive audio and video” modifier. A few payers and some institutional claims still want it instead of 95.
93: Audio-only (phone) visit, where the payer covers it. Some payers ask for FQ instead.

Add-on 90785 (interactive complexity) can be billed with this code when communication was made harder by something like an interpreter, a third party or caregivers in conflict.

Typical place of service codes

11: Office. The usual in-person place of service for private practice.
10: Telehealth with the client in their home.
02: Telehealth with the client somewhere other than home (work, car, a clinic).
12: In person at the client’s home.
03: School.
53: Community mental health center.

Common questions

Is 90791 time-based?: No. CPT doesn’t set a time for 90791; you bill it once for the evaluation regardless of length. Document the time anyway, since some payers review long or repeated evaluations.
How often can I bill 90791?: CPT allows it more than once when a new evaluation is needed, but many payers limit it to once per episode of care or once every 6 to 12 months per clinician. Check the payer’s policy before billing a second one.
What is the difference between 90791 and 90792?: 90791 is the evaluation without medical services. 90792 adds medical services (such as a physical exam or prescribing) and is billed by physicians and other prescribers.
Can I bill 90791 and 90837 on the same day?: Not by the same clinician for the same client. Bill the intake as 90791 and start psychotherapy codes at the next session.

CPT® is a registered trademark of the American Medical Association. This page summarizes common billing practice in plain language and isn’t billing or legal advice; payer policies vary, so check each payer’s current rules.