Diagnostic Evaluations: CPT 90791 and 90792
What CMS.gov says these two codes are, how often each can be billed, and what the note has to show. Checked against CMS.gov on 9/29/26.
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Diagnostic Evaluation at a glance
This page covers diagnostic evaluation for mental health billing: what the codes cover, how payers apply them, and what to document. Psychotherapists and psychiatrists both use these codes, so the sections below call out differences where they matter. Payer rules vary, so confirm current requirements with the payer before you bill.
What CMS.gov says these codes are
Quotes are copied from CMS.gov pages. Each quote names its source. Contractor articles are written by Medicare Administrative Contractors (MACs), the companies that process Medicare claims for a region, and apply to their own region.
Code list entry
“Psychiatric diagnostic evaluation”
What the service is
“Psychiatric evaluation to create a treatment plan based on a psychiatric disorder's causes, symptoms, course, and consequences.”
“A psychiatric diagnostic evaluation or a psychiatric diagnostic evaluation with medical services can be conducted once, at the onset of an illness or suspected illness.”
“If a psychiatric diagnostic evaluation with medical assessment is performed, the physician or non-physician practitioner (NPP) may use CPT code 90792 or an evaluation and management (E/M) code.”
Time range and documentation
Every timed code needs the date of service and the start and end time of the service.
| Code | Service | Time range | Document |
|---|---|---|---|
| 90791 | Psychiatric diagnostic evaluation (no medical services)Psychotherapists and psychiatrists. Not billed with any psychotherapy code on the same date (NCCI). | No time range defined | Date of service + start and end time of the service (recommended) Documentation rules |
| 90792 | Psychiatric diagnostic evaluation (with medical services)Prescribers. No E/M on the same date (NCCI). | No time range defined | Date of service + start and end time of the service (recommended) Documentation rules |
How often and with what?
- Once, at the onset of an illness or suspected illness. A repeat is allowed after a break of about 6 months, an inpatient admission, a significant change in mental status, or when the diagnosis needs clarifying.
Source: CMS Coverage Database, Article A57480 (WPS, rev. 1/1/2026) - Not reported with any psychotherapy code on the same date. E/M codes are not reported with 90791 or 90792.
Source: CMS, NCCI Medicare Policy Manual, Ch. XI (1/1/2026) - Not billed with crisis psychotherapy 90839/+90840.
Source: CMS, Psychotherapy for Crisis (page modified 02/25/2026)
These are Medicare rules. Private payers and state Medicaid programs set their own; ask each payer. Full list: frequency and documentation rules.
Psychotherapists and psychiatrists
Psychotherapists
90791 is your evaluation code. Do not bill psychotherapy on the same date as the evaluation.
Psychiatrists
90792 covers an evaluation with medical services. Contractor article A57520 says a prescriber may use 90792 or an E/M code for an evaluation with medical assessment.
Frequently asked questions
How often can I bill 90791?
Once, at the onset of an illness or suspected illness, according to Medicare contractor article A57480. A repeat is allowed after a break of about six months, an inpatient admission, a significant change in mental status, or when the diagnosis needs clarifying. Commercial payers set their own limits, so ask each one.
What is the difference between 90791 and 90792?
Both are psychiatric diagnostic evaluations. 90792 includes medical services, which is why it is used by prescribers. CMS lists both under the name “Psychiatric diagnostic evaluation.” Contractor article A57520 says a practitioner who does an evaluation with medical assessment may use 90792 or an E/M code.
Can I bill psychotherapy on the same day as 90791?
No. Under the Medicare NCCI policy manual, 90791 and 90792 are not reported with individual, group, family, crisis or other psychotherapy codes for the same date of service. E/M codes are also not reported with them.
Is there a time range for 90791 and 90792?
Neither CPT nor CMS sets a minute range for these codes. Record the date of service and the start and end time of the evaluation anyway.
More CPT code guides
CMS.gov sources
- CMS Coverage Database, Article A57480 (WPS, rev. 1/1/2026)
- CMS Coverage Database, Article A57520 (First Coast, rev. 1/1/2025)
- CMS, Medicare & Mental Health Coverage (MLN1986542, March 2026)
- CMS, NCCI Medicare Policy Manual, Ch. XI (1/1/2026)
- CMS, Psychotherapy for Crisis (page modified 02/25/2026)
Current as of last search (9/29/26). Reconfirm before publishing. For quick reference only: verify against the current AMA CPT manual and each payer's policy before billing. Operational billing guidance, not legal advice.
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