The 90791 CPT code covers a psychiatric diagnostic evaluation without medical services. It is the intake code: the comprehensive initial assessment where a clinician takes the history, performs a mental status exam, establishes a diagnosis and sets a treatment direction.
Two things about it surprise people. It is not a timed code, unlike the psychotherapy codes it sits next to. And if the clinician prescribes or manages medication during that evaluation, the correct code is 90792, not 90791.
Below: what the code covers, why time thresholds do not apply, how 90791 differs from 90792 and from 90837, how often payers let you bill it, what can share the claim, telehealth, and the documentation a 90791 note needs to survive review.
What the 90791 CPT Code Covers
The official descriptor is "psychiatric diagnostic evaluation". The companion code 90792 is "psychiatric diagnostic evaluation with medical services". The distinction between them is the entire reason miscoding this pair is one of the most common errors in psychiatric billing.
A 90791 evaluation generally includes a full biopsychosocial history, a mental status examination, a risk assessment, a diagnosis, and a recommended treatment plan. It is billable by psychologists, licensed clinical social workers, licensed professional counselors, marriage and family therapists and other qualified non-prescribing clinicians, subject to scope of practice and payer credentialing.
90791 Is Not a Timed Code
There is no minute threshold for 90791. What qualifies the encounter is completing and documenting a full evaluation, not hitting a clock target. Most evaluations run somewhere between 45 and 90 minutes, but that range is a description of practice, not a billing requirement.
This is where clinicians coming from the psychotherapy codes get tripped up. 90837, 90834 and 90832 are strictly time-defined. 90791 is not. CMS lists the time-based psychotherapy services as 90832 through 90838 and requires start and stop times for those codes specifically; 90791 is absent from that list, which is the clearest confirmation that it is untimed.
The practical consequence: do not withhold a 90791 because the session ran short, and do not assume a long evaluation earns anything extra. Document the completeness of the assessment instead of its duration.
90791 vs 90792: The Prescriber Line
Use 90791 when no medical services are provided, and 90792 when they are. Medical services means a medical assessment component such as a physical examination, ordering or interpreting labs, or prescribing and managing medication.
| 90791 | 90792 | |
|---|---|---|
| Descriptor | Psychiatric diagnostic evaluation | Psychiatric diagnostic evaluation with medical services |
| Who reports it | Non-prescribing clinicians: psychologists, LCSWs, LPCs, MFTs | Prescribers: psychiatrists, and NPs or PAs with prescribing authority |
| Includes medication management | No | Yes |
| Timed | No | No |
One detail worth knowing for prescriber-led intakes: CMS states that a physician or non-physician practitioner may use either 90792 or an evaluation and management code for the encounter. The choice is between those two, not 90791 plus an E/M code on top.
90791 vs 90837: An Intake Is Not a Therapy Session
These two get compared constantly because both describe a long first appointment, but they are different services. 90791 is a diagnostic assessment: the output is a diagnosis and a plan. 90837 is treatment: the output is a therapeutic intervention delivered for 53 minutes or more.
A first appointment is normally the evaluation, so it bills as 90791. Once treatment begins, subsequent sessions bill as psychotherapy under the time-based codes. Our guide to psychiatric billing covers how the psychotherapy and evaluation and management components fit together after intake.
How Often You Can Bill 90791
This is payer policy, not a CPT rule, and it is a leading cause of denials. Most plans cover a psychiatric diagnostic evaluation once per episode of care, with common guidance falling somewhere in the range of every six to twelve months for the same patient and provider.
What that means in practice: a returning patient after a long gap may legitimately warrant a new evaluation, and a patient transferring between clinicians inside the same organization may not. Because the limits differ by plan, the reliable move is to check the specific payer's medical policy before the appointment rather than after the denial. Repeat and duplicate intakes are a routine denial category, and they are avoidable at the scheduling step.
What Else Can Go on the Claim
Interactive complexity (90785) can be reported with 90791 and 90792. The CMS billing and coding article for psychiatric diagnostic evaluation and psychotherapy services lists the add-on as used in conjunction with the diagnostic evaluation codes, alongside the psychotherapy codes. It applies when specific communication factors complicate delivery, such as a language barrier, caregiver interference, or a mandatory reporting discussion. CMS also notes that if a patient is unable to communicate by any means, 90785 should not be billed.
Psychotherapy is a different story. Payers and claim edits generally will not accept a psychotherapy code on the same day as a psychiatric diagnostic evaluation from the same provider for the same patient, because the evaluation is treated as the service of record for that encounter. Confirm the specific rule with each payer before building it into a workflow, since the enforcement mechanism varies.
Can You Bill 90791 for Telehealth?
Generally yes. 90791 is commonly delivered and reimbursed by telehealth, reported with the telehealth modifier and place-of-service code the payer requires. Telehealth requirements have been revised repeatedly since 2020 and differ between Medicare and commercial plans, so verify the current expectation with each payer rather than carrying forward last year's configuration, and document the session modality in the note.
What Payers Check on a 90791 Note
Because the code is untimed, the note carries the entire burden of proving the service. Six elements make a 90791 defensible.
- Presenting problem and history. The biopsychosocial context that prompted the evaluation.
- Mental status examination. Its absence is one of the most reliable ways to lose a 90791 on review.
- Risk assessment. Suicidality, self-harm and safety, documented explicitly rather than implied.
- A diagnosis with its ICD-10 code. An evaluation that establishes no diagnosis invites a question about what the service accomplished.
- Treatment recommendation. The plan the evaluation produced, including the modality and cadence proposed.
- Modality and date of service details, including telehealth specifics where they apply.
Note format matters as much as content. A structured note where a reviewer can find the mental status exam and the risk assessment without hunting is easier to defend than a narrative that contains the same information scattered through prose.
What a Denied 90791 Costs, and How to Look Up What It Pays
There is no single national figure worth quoting, and any article that gives you one is guessing at your contract. Medicare rates for 90791 are published in the CMS Physician Fee Schedule lookup and vary by locality. Commercial rates are set by your contract, so pull your own fee schedule.
The cost that matters is not the line item. A denied intake sits at the front of the treatment relationship, so the rework lands while the patient is still being scheduled: staff time to identify the denial, correct and resubmit, and the delay before the claim clears. Handling this upstream is what good behavioral health billing looks like, because a denial at intake also delays every downstream claim for that episode.
Where mdhub Fits
Two parts of the intake problem are operational rather than clinical, and both sit outside the clinical hour.
The first is everything before the evaluation: verifying coverage, confirming the payer's frequency policy for a diagnostic evaluation, and getting the patient booked with the right clinician. Sarah, the mdhub AI Admissions Coordinator, handles that admissions path, which is where a repeat-intake denial gets prevented rather than appealed.
The second is the note. Emma, the mdhub AI Clinical Assistant, drafts clinical documentation and handles CPT coding, with a quality layer that checks notes against payer expectations, so an intake note reaches the biller with its mental status exam, risk assessment and diagnosis in place. On the claim side, Eric, the mdhub AI Billing Specialist, handles submission and denials. Clinics using mdhub save 2+ hours per clinician per day and see up to 50% lower operational costs.
mdhub empowers clinicians rather than replacing their judgment. Emma drafts, the clinician reviews and signs. The assessment, the diagnosis and the risk determination stay with the person who conducted the evaluation. Talkiatry chose mdhub's AI clinical documentation tool to reduce the administrative load on its clinicians. For more on how the documentation side works, see our approach to AI clinical documentation for behavioral health, and what mental health billing software built for behavioral health actually does.
Streamline Your Practice
90791 is a simple code with an unforgiving note. Because nothing about the time defends it, the assessment has to be visible on the page: history, mental status, risk, diagnosis, plan. Get that consistently and the intake claim stops being a recurring rework item. To see how this runs inside a live practice, book a demo with the mdhub team.
90791 is a psychiatric diagnostic evaluation without medical services. 90792 is the same evaluation with medical services, meaning a medical component such as a physical examination, ordering labs, or prescribing and managing medication, so it requires a clinician with prescribing authority. If medication is prescribed or managed during the intake, 90792 applies rather than 90791. CMS also states that a physician or non-physician practitioner may use either 90792 or an evaluation and management code for the encounter, so the choice for a prescriber is between those two rather than adding an E/M code to 90791. Miscoding this pair is one of the most common psychiatric billing errors.
No. 90791 is an untimed code, which sets it apart from the psychotherapy codes next to it. CMS identifies 90832 through 90838 as the time-based psychotherapy services and requires start and stop times for those; 90791 is not in that group. What qualifies the encounter is a complete, documented evaluation rather than a minute threshold. Most evaluations run roughly 45 to 90 minutes, but that is a description of typical practice and not a billing requirement, so a thorough shorter evaluation is still billable and a longer one does not earn an additional line.
This is payer policy rather than a CPT rule. Most plans cover a diagnostic evaluation once per episode of care, and guidance commonly lands in the range of every six to twelve months for the same patient and provider. A returning patient after a long absence may warrant a new evaluation; a patient moving between clinicians within one organization often does not. Because the limits genuinely differ between plans, check the payer's medical policy before the appointment. Repeat or duplicate intakes are a routine denial category and the cheapest place to catch one is at scheduling.
Generally no. Payers and automated claim edits typically reject a psychotherapy code billed on the same day as a psychiatric diagnostic evaluation by the same provider for the same patient, because the evaluation is treated as the service of record for that encounter. Interactive complexity is the exception worth knowing: CMS lists 90785 as reportable in conjunction with 90791 and 90792. Because enforcement varies by payer and edit set, confirm the specific pairing rule with each plan before you build it into a scheduling or billing workflow.
