The mental health issues in the U.S. are worsening. According to the 2021 National Survey on Drug Use and Health, every 1 in 5 persons in the country experiences some kind of mental illness each year, and the number is rising. This is a point of concern for both the patients and healthcare providers.
More patients mean more insurance claims. So, providers must bill mental health claims accurately. Otherwise, they risk losing billions.
CPT code 90791 is one of the most frequently used behavioural health codes. Yet, many billers make mistakes while filing their claims. So, how can you use 90791 correctly?
That’s what we are going to find out in this blog. We will start with a simple description, then move to more important topics like use case scenarios, modifiers, and billing guidelines. So, let’s begin.
CPT Code 90791 – Description
CPT code 90791 is officially defined as:
“Psychiatric diagnostic evaluation without medical services.”
90791 is used when physicians perform an initial (but comprehensive) evaluation of a patient’s mental health status. The assessment can last up to 90 minutes, and usually includes:
- A complete medical and psychiatric history
- Mental status examination
- Evaluation of the patient’s ability and capacity to respond to treatment
- Development of an initial treatment plan
As mentioned in the Centers for Medicare and Medicaid Services (CMS) Local Coverage Determinations (LCD) manual, 90791 is categorized as an “integrated biopsychosocial assessment.” What does it mean? Well, simply put, it means that during the mental health evaluation, physicians consider all factors, including biological, psychological, and social elements.
An important thing to note here is that CPT code 90791 is purely a diagnostic billing code. This means that it does not include medical services like medication management.
Also, like other psychiatric CPT codes, use 90791 only when it is the most suitable. If an evaluation and management (E/M) service or pharmacological code better describes the service provided, use that instead.
The code is intended for use by licensed mental health professionals, including:
- Licensed Clinical Social Workers (LCSW)
- Clinical Psychologists
- Psychiatrists
In addition to this, 90791 is also valid for telehealth services if proper modifiers are provided.
Scenarios Where CPT Code 90791 is Applicable
Now that we have discussed what CPT code 90791 is, let’s briefly explore some real-world scenarios in which it can be used.
Initial Evaluations for New Patients
The most common application of CPT code 90791 is for the first mental health evaluation session with a new patient. This initial meeting focuses on gathering comprehensive information about the patient’s presenting problems, mental health history, and current symptoms to establish a diagnosis and formulate a treatment plan.
Reassessments After Extended Absence
Another scenario in which 90791 can be used is when a patient needs a reevaluation after a prolonged period. If a patient returns to treatment after a significant break in care (usually 6 or 12 months), many insurance payers permit the use of CPT code 90791 for a comprehensive reassessment. That’s especially applicable if the patient exhibits new symptoms or a significant change in the old condition.
New Episode of Care for an Established Patient
When an established patient presents with a new mental health concern that is substantially different from previous treatment episodes, CPT code 90791 may be appropriate for a complete reevaluation. However, before using the code in this scenario, ask yourself, is a complete reassessment necessary? If the answer is yes, and the assessment would be as comprehensive as an initial evaluation, then you can use 90791.
Applicable Modifiers for CPT Code 90791
The following are some modifiers that apply to CPT code 90791:
| Modifier | Description | Usage Context |
|---|---|---|
| 52 | Reduced services | Used when the service provided is less comprehensive than the full service described by the code. |
| 59 | Distinct procedural service | Applied when multiple procedures are performed on the same day that would not typically be reported together. |
| 95 | Synchronous telemedicine service rendered via a real-time interactive audio and video system | Essential for a psychiatric diagnostic evaluation conducted with both audio and video components (telehealth). |
| GT | Via interactive audio and video telecommunication systems (telehealth services) | Used for telehealth. Although it has been replaced by 95 in many contexts, some payers still require it. |
| HE | Mental health program | Indicates the service is part of a mental health program. |
| HF | Substance abuse program | Used when the diagnostic evaluation is specifically part of a substance abuse treatment program. |
| HR | Family/couple with client present | Used when family members are involved in the evaluation process with the client present. |
CPT Code 90791 – Billing & Reimbursement Guidelines
The following are some billing guidelines that you must consider while filing claims for CPT code 90791:
Provide Detailed Documentation
Documentation is the key to successful billing. Appending the appropriate documents and medical records is essential to prove the medical necessity of the rendered service. The following are some documents that you must always attach to 90791 claims:
- Complaint and presenting problem
- Complete psychiatric history
- Current medications and medication history
- Diagnostic formulation with specific DSM-5/ICD-10 codes
- Family’s psychiatric and medical history
- Mental status examination findings
- Relevant medical history
- Risk assessment (suicide, homicide, self-harm)
- Session start and end times
- Social and developmental history
- Substance use assessment
- Total time spent with the patient
- Treatment recommendations and plan
Report Valid ICD-10 Codes For Medical Necessity
Insurance providers require valid ICD-10 diagnosis codes to support the medical necessity of the procedure or services provided. The following are some ICD-10 codes that can support the use of 90791:
- E66.01: Morbid (severe) obesity due to excess calories
- F01.511: Vascular dementia, unspecified severity, with agitation
- F01.518: Vascular dementia, unspecified severity, with other behavioral disturbance
- F01.52: Vascular dementia, unspecified severity, with psychotic disturbance
- F01.53: Vascular dementia, unspecified severity, with mood disturbance
- F01.54: Vascular dementia, unspecified severity, with anxiety
- F06.2: Psychotic disorder with delusions due to a known physiological condition
To get the complete list of ICD-10 codes that fulfill medical necessity for code 90791, you can check the official CMS Psychiatry and Psychology Services guide.
Understand When Not to Use CPT Code 90791
To avoid claim denials, it’s equally important to know when NOT to use this code:
- Regular ongoing therapy sessions (use 90834, 90837, etc.)
- When medical services are provided during the evaluation (use 90792)
- For brief assessments or screenings (consider codes like 96127)
- Multiple times within a short period for the same patient without significant clinical changes
Wrapping Up
In this blog, we tried our best to simplify CPT code 90791 for you. However, we realize that it is a lot of information to digest. So, let’s do a quick recap.
- 90791 represents an initial mental health evaluation for diagnosis.
- The assessment session can last up to 90 minutes.
- Appending the correct modifiers like 52, 95, and HF (when necessary) is essential to avoid claim denials.
Unfortunately, even after following all the guidelines, many healthcare providers face claim denials. You can partner with a reliable medical billing company to get the best mental health billing services and improve your clean claim rate.
