Code 90791 is officially a “diagnostic evaluation,” but you might know it better as an initial assessment. Learn how to bill your first session with a client.
December 21, 2023 • Updated on October 16, 2026
By the Headway Editorial Team
13 min read
By the Headway Editorial Team
What to know
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Code 90791 represents your initial assessment of your client. It’s the session where you gather information about the clients symptoms in order to establish a diagnosis and formulate their treatment plan.
This is is how the American Medical Association defines 90791 in the official CPT codebook:
Psychiatric diagnostic evaluation (without medical services)
Psychiatric diagnostic evaluation is an integrated biopsychosocial assessment, including history, mental status, and recommendations.
The evaluation may include communication with family or other sources and review and ordering of diagnostic studies.
Many types of licensed mental health providers can use CPT code 90791.This code is most frequently used by:
Yes, code 90791 is commonly used for an intake session. Typically, prior authorization is not required to use this code.
Your documentation for this code should include all the standard elements of an intake note, including:
Complete documentation for 90791 should include both the intake note and your bio-psycho-social assessment, as well as any diagnostic-specific assessment like the PHQ-9 for depression, GAD 7 for anxiety, or the Alcohol Use Disorders Identification Test (AUDIT-C) for substance abuse.
It’s important to use the code that most accurately reflects the time you spent with the patient to treat their condition, and ensure that documentation for the session supports the chosen code.
Simplify insurance and save time on your entire workflow — from compliance and billing to credentialing and admin.
Reimbursement rates for sessions billed with 90791 will vary depending on the plan, your contract, your location, and your license type. The right partnership can boost reimbursement rates, too.
Headway has strong relationships with many of the nation’s top insurance carriers, allowing us to negotiate competitive reimbursement rates that make accepting insurance both easy and profitable for our providers. Headway providers can earn around $27,000 more per year than they would through self-credentialing.
Many payers will only reimburse 90791 once per year, per client. Some allow it to be used only once per patient, per episode of care. If a patient leaves therapy and returns after a long gap, it may be appropriate to use code 90791 again, since their return kicks off a new episode of care.
Code 90791 cannot be reported on the same day as an evaluation and management service for the same patient, or on the same day as psychotherapy services (including for crisis). Use code 90785 in conjunction with 90791 when the diagnostic evaluation includes interactive complexity services.
Code 90791 is used to represent an intake assessment for care that does not include medical services.
In contrast, code 90792 is used for an intake assessment for care that does include medical services, such as ordering diagnostic work or prescribing medications. For this reason, 90792 can only be billed by a qualified licensed provider like a psychiatrist or nurse practitioner.
This document is intended for educational purposes only. It is designed to facilitate compliance with payer requirements and applicable law, but please note that the applicable laws and requirements vary from payer to payer and state to state. Please check with your legal counsel or state licensing board for specific requirements.
Several billing codes may be used along with CPT code 90791. These include:
Remember that code 90791 is used for sessions that do not include medical services. If you’re looking to add on codes for medical services, you’ll likely need to use code 90792 instead.
If an intake session occurs over telehealth, you can still use CPT code 90791. Just remember that some additional information is required when you bill for telehealth appointments.
For example, you’ll need to include place of service and CPT modifier codes to indicate the appointment occurred over telehealth. Commonly, providers use the place of service codes 10 or 02 (for synchronous appointments that took place while the client was in or outside their home, respectively) and the CPT modifier code 95 (which denotes a synchronous appointment conducted on platforms such as a HIPAA-compliant version of Zoom).
In addition to confusing codes 90791 and 90792, as discussed above, providers may run into difficulty if they try to use code 90791 repeatedly for the same patient. Typically, it can only be used once per patient, per year. It should not be used for follow-up visits or on the same day as psychotherapy services are delivered.
Another common mistake is failing to provide enough documentation along with code 90791. Make sure you’ve included all relevant components listed above. Headway providers can use the platform’s included intake and documentation templates to make sure nothing falls through the cracks.
CPT code 90791 is used for an initial assessment and diagnosis of a client, typically during an intake session. Code 90837, meanwhile, is used for regular, ongoing care. It describes a 60-minute psychotherapy session.
Generally, no. An assessment appointment is considered separate from treatment.
Payers set their own limits. Some reimburse code 90791 only once per patient, per episode of care. Others reimburse it once per patient every year, or even every six months.
As of 2026, Medicare reimburses psychologists billing code 90791 at around $173. Rates may vary for other license types, as well as for providers billing commercial plans.
No, 90791 is not associated with any specific time component. But make sure to document other session details, including the client’s personal information, place of service, and your full assessment of their condition.
There are a lot of nuts and bolts that go into running a private therapy practice, from the complexities of billing to insurance compliance requirements.
Headway is here to help with all of those tasks, streamlining and simplifying administrative responsibilities like credentialing, scheduling, documentation, and billing. Plus, our providers enjoy consistent and competitive bi-weekly pay, thanks to our partnerships with leading payers. We take care of all of your behind-the-scenes needs to make being a therapist simpler and more profitable.
This content is for general informational and educational purposes only and does not constitute clinical, legal, financial, or professional advice. All decisions should be made at the discretion of the individual or organization, in consultation with qualified clinical, legal, or other appropriate professionals.
© 2026 Therapymatch, Inc. dba Headway. All rights reserved. No part of this publication may be reproduced without permission.
Understand the ins and outs of CPT codes to help make documentation and billing more efficient — and give you more time to focus on other areas of your practice.
Headway strives to simplify billing insurance so you can focus on providing care. Read our comprehensive guide to mental health billing.
Understand the ins and outs of CPT codes to help make documentation and billing more efficient — and give you more time to focus on other areas of your practice.
