Mastering CPT Code 90791: The Psychiatric Diagnostic Evaluation

Updated on: July 23, 2025

Introduction

Accurate use of CPT codes is essential for clinicians, billing teams, and practice administrators. Among these, CPT code 90791—the psychiatric diagnostic evaluation without medical services—is a foundational billing code for new or re-evaluation mental health clients. Mastering this one code enhances:

• Claim accuracy and timely reimbursement
• Compliance with payer policies and industry standards
• Risk management pertaining to audits and denials
• Clinical clarity, via structured intake and assessment

Within this article, we’ll unpack 90791 in depth: its definition, audience, documentation requirements, add-on options, reimbursement ranges, common mistakes, and best practice guidelines. We’ll also include charts to help you visualize time structures, billing combinations, and reimbursement variations.

Understanding CPT Code 90791

Definition:
CPT code 90791 is a psychiatric diagnostic evaluation without medical services, typically used for a thorough biopsychosocial intake. A comprehensive evaluation includes:

• A full psychiatric and medical history
• Mental status examination
• Diagnostic impressions
• Initial treatment plan
• Evaluation of client’s capacity and receptiveness

This intake session serves as the foundation for treatment planning and must stand alone—no concurrent E/M or psychotherapy codes should be billed on the same day by the same provider

Key Features:

• Includes integrative interviewing and assessment
• Performed at the onset of treatment or after significant changes
• Used only once per provider per episode of care unless complexity warrants repeats

Distinction Between 90791 and 90792

Although both codes describe psychiatric evaluations, the critical difference lies in medical involvement:

• 90791: Non-medical evaluation (by psychologist, counselor, social worker)
• 90792: Includes medical services (prescribing, lab use)—reserved for psychiatrists or psychiatric nurse practitioners

Attempting to use 90791 for sessions that include medication review or prescribing risks rejection or audit triggers. Use billing systems to ensure proper differentiation.

Who Can Bill 90791

Eligible professionals include:

• Licensed Clinical Social Workers (LCSW)
• Licensed Professional Counselors (LPC)
• Licensed Mental Health Counselors (LMHC)
• Licensed Marriage and Family Therapists (LMFT)
• Clinical Psychologists (PhD, PsyD)

Note: Certain payers may restrict non-MD evaluations, especially for Medicare or Medicaid—always verify local policies.

Time Requirements and Add-On Codes

Minimum and Maximum Session Time

• Minimum: 16 minutes
• Maximum: 90 minutes
• Sessions shorter than 16 minutes or over 90 minutes should not use 90791 alone.

Add-On Coding for Extended Time

When the intake exceeds 90 minutes:

Note: Use of add-on codes depends on payer allowance. Some commercial payers may not reimburse for prolonged codes.

Documentation Essentials

Medicare outlines key documentation requirements for 90791, including:

1. Complete psychiatric and medical history
2. Mental status exam
3. Presence of a defined primary diagnosis
4. Appraisal of client’s insight and capacity
5. Formulation of initial treatment plan
6. Only one 90791 per day, no simultaneous E/M by same provider

Detailed charting helps support audits and streamline reimbursement.

Reimbursement Rates and Payer Variability

Medicare Reimbursement Trends

Rates improve over time but can fluctuate based on policy updates.

Private Insurance

• Masters-level clinicians: $90–$150
• Doctoral-level clinicians: $110–$200
• Psychiatrists: $150–$300

Session Type Comparison

Based on SimplePractice data (2021):

90791 yields higher reimbursement, especially as a first session billing.

State-by-State Variations

High-cost states (e.g., California, NY, Hawaii) pay more but claim denials and audits are more common in these regions

Common Pitfalls and Best Practices

1. Over-Billing 90791

Most payers allow one per treatment episode or year. Re-billing without substantial new evaluation invites denials

2. Inadequate Documentation

Claims lacking full biopsychosocial content or session timing are at high risk for denial. Use structured note templates.

3. Incorrect Code Use with Medical Services

Including medication review or prescribing excludes use of 90791—use 90792 instead.

4. Incorrect Pairing with Other Codes

Never pair psychotherapy or E/M claims on the same day as 90791 by the same provider.

5. Ignoring Add-On Eligibility

916 add-on codes should only be used when session times exceed 90 minutes and are allowed by payers. Document face-to-face duration.

Interactive Complexity and Add-On Coding

CPT 90785 covers interactive complexity, applicable when session includes:

• Maladaptive communication or high anxiety
• High caregiver involvement or conflict
• Sentinel events reporting
• Use of devices/translators during session

How to Bill:

Combine 90785 with primary psychiatric or psychotherapy codes (e.g. 90791, 90834, 90837) when complexity is present.

Important: 90785 cannot be billed with crisis psychotherapy (90839) or E/M codes alone.

Frequency, Telehealth, and Billing Scenarios

1. Re-Billing 90791

Allowed under certain conditions: new behavioral health condition, major status change, or after a 6-month care gap

2. Telehealth

90791 may be billed via telehealth with proper modifiers (e.g., -95) and POS codes—check payer rules.

3. Dual Billing on Same Day

Different providers may bill separately (e.g., 90791 by counselor and E/M by psychiatrist), but check insurer rules regarding consolidated claims

Tools and Templates for Efficient Use

Intake Note Template

1. Start/End Times
2. Chief Complaint & Symptom Description
3. History: psychiatric, medical, family, substance
4. Mental Status Exam
5. Diagnosis(es)
6. Treatment Plan
7. Added Complexity or Extended Time Documentation

Time and Billing Chart

Verification Checklist

• Intake specifics complete?
• Time rules satisfied?
• Add-on codes applicable?
• Telehealth modifiers correct?
• Payor policies verified?

Conclusion

CPT code 90791 is critical in behavioral health billing and clinical assessment. When used correctly, it ensures:

• Strong foundation for treatment planning
• Appropriate reimbursement
• Compliance with payer and regulatory standards

To implement effectively:

1. Use only once per episode without overlap
2. Document thoroughly and monitor time
3. Add complexity or extended time codes when warranted
4. Confirm payer policies, especially regarding telehealth or repeat evaluations

Finally, streamline your documentation with tools like DocScrib. With AI-powered SOAP note generation, you’ll save time, reduce billing errors, and preserve your focus on client care.

Experience seamless, AI-powered documentation—join DocScrib today and book your free demo to optimize your billing and clinical workflow.