How can I bill for an incomplete psychiatric diagnostic evaluation (CPT 90791)?

Billing for Incomplete Psychiatric Evaluations

You cannot bill CPT 90791 for an incomplete psychiatric diagnostic evaluation; instead, bill using time-based Evaluation and Management (E/M) codes that reflect the actual work performed and documented during the encounter.

The Core Billing Principle

When a psychiatric evaluation cannot be completed—whether due to patient inability to cooperate, premature termination, or clinical circumstances preventing comprehensive assessment—the CPT 90791 code is inappropriate because it requires completion of a diagnostic psychiatric evaluation. The APA Practice Guidelines explicitly acknowledge that "the evaluation may also require several meetings, with the patient, family, or others, before it can be completed" and that "recommended areas of inquiry may need to be postponed until later visits" 1. This recognition that evaluations are not always completable in one session is critical to understanding billing options.

What to Bill Instead

Use time-based E/M codes (99202-99205 for new patients, 99212-99215 for established patients) based on:

• Total time spent on the date of encounter (including face-to-face and non-face-to-face time on that day)
• Medical decision-making complexity of what was actually assessed
• Documentation of what was completed and why the evaluation could not be finished

The shift to E/M codes for incomplete evaluations became particularly relevant after 2013 coding changes, when psychiatrists were directed to use E/M codes for encounters related to medical services 2.

Documentation Requirements

Your documentation must clearly establish:

• What was attempted: Document the intended scope of the evaluation
• What was completed: Specific elements of history, mental status examination, and assessment that were obtained
• Why it was incomplete: Patient factors (agitation, psychosis, inability to engage), time constraints, or clinical circumstances
• The plan: Whether you will complete the evaluation at a subsequent visit or if this represents the extent of assessment possible

This approach aligns with the APA guideline principle that "judgments concerning clinical care depend on the clinical circumstances and data available for an individual patient" 1.

Common Pitfalls to Avoid

Do not:

• Bill 90791 with a modifier hoping for partial payment—this code represents a complete service
• Use "no-show" or "canceled appointment" codes if the patient was seen but couldn't complete the evaluation
• Fail to document the reason for incompletion, which invites claim denials

Do:

• Document time spent meticulously (start and stop times)
• Note specific barriers to completion
• Code conservatively based on what was actually accomplished
• Consider whether the encounter meets criteria for crisis intervention codes if applicable

Selecting the Appropriate E/M Level

Choose your E/M code level based on either:

1. Time-based coding: If you spent 30-44 minutes, use 99203 (new) or 99213 (established); 45-59 minutes = 99204/99214, etc.
2. Medical decision-making: Low complexity = 99202/99212, Moderate = 99203/99213, High = 99204/99214

For incomplete psychiatric evaluations, the medical decision-making is often at least moderate complexity given the psychiatric nature of the presentation 2.

Special Circumstances

If the patient becomes acutely agitated or dangerous and requires crisis intervention, consider crisis codes (99281-99285 in emergency settings) rather than standard E/M codes, as these better reflect the actual clinical work performed.

The coding guidance emphasizes that psychiatrists should bill for "specific services rather than designating all care as psychotherapy" 3, which supports using the most accurate code for the actual service provided rather than defaulting to incomplete psychiatric evaluation billing.