CPT Code 90791: 2026 Billing and Documentation Guide. What Is CPT Code 90791?

CPT code 90791 reports a psychiatric diagnostic evaluation without medical services. It covers comprehensive behavioral health assessments involving psychiatric history, mental status examination, diagnostic formulation, and an initial treatment plan.

Accurate billing requires appropriate provider credentials, documentation supporting medical necessity, and compliance with payer-specific requirements. Understanding the code's scope, frequency limitations, telehealth rules, and differences from related CPT codes helps practices avoid incorrect claims and preventable denials.

Psychiatric Services Included in CPT 90791

CPT 90791 describes a comprehensive psychiatric diagnostic evaluation used to assess a patient's mental health condition and establish treatment recommendations.

The evaluation generally includes:

• Presenting symptoms and psychiatric history
• Relevant medical, family, and psychosocial history
• Mental status examination
• Clinical risk assessment
• Diagnostic impression
• Initial treatment recommendations and referrals

CPT 90791 excludes medical evaluation and management services. Evaluations that include medical are reported with CPT 90792, which only physicians and NPPs with prescribing authority (NP, PA, CNS) may bill. Psychologists, LCSWs, LPCs, MFTs and MHCs report 90791.

Eligible Providers and Appropriate Use of 90791

Qualified professionals who may report CPT 90791, subject to payer requirements and scope of practice, include:

• Clinical psychologists
• Licensed clinical social workers (LCSWs)
• Licensed professional counselors (LPCs)
• Mental health counselors (MHCs)
• Marriage and family therapists (MFTs)
• Psychiatrists and eligible nonphysician practitioners

Medicare has permitted qualifying MFTs and MHCs to enroll and bill independently for covered mental health services since January 1, 2024.

CPT 90791 is appropriate for an initial psychiatric diagnostic assessment or a medically necessary reassessment. Routine psychotherapy, brief follow-up evaluations, and medication-management visits should be reported using codes that accurately describe the services performed.

CPT 90791 Documentation Requirements

Documentation must support the diagnostic evaluation and establish medical necessity.

A complete clinical record should include:

1. Presenting problem: Symptoms, severity, duration, and functional impact.
2. Clinical history: Relevant psychiatric, medical, psychosocial, and previous treatment information.
3. Mental status examination: Findings appropriate to the patient's clinical presentation.
4. Risk assessment: Relevant safety concerns and clinical judgment.
5. Diagnostic impression: Supported diagnosis or provisional assessment with appropriate ICD-10-CM coding.
6. Treatment plan: Recommended interventions, referrals, and follow-up arrangements.

Records should also include the service date and appropriate provider authentication. Documentation must reflect the work performed rather than rely solely on a standardized intake template.

Time Requirements and Repeat Evaluation Rules

CPT 90791 is not a time-based code. Unlike psychotherapy codes 90832, 90834, and 90837, its CPT descriptor does not specify a minimum or maximum session duration.

However, practices should document encounter time when required by the payer or relevant documentation policy.

Repeat evaluations may be medically necessary following:

• An extended interruption in treatment
• Significant changes in mental status
• Psychiatric hospitalization
• A need for diagnostic clarification

Medicare contractor Article A57480 discusses these circumstances and references an approximately six-month treatment interruption. This guidance is contractor-specific and should not be treated as a universal payer rule.

Before rebilling 90791, verify frequency restrictions and document why another comprehensive assessment is necessary.

Telehealth and Same-Day Billing Restrictions

CPT 90791 may be billed through telehealth when applicable coverage and reporting requirements are satisfied.

Billing element	Consideration
POS 10	Telehealth when the patient is at home
POS 02	Telehealth when the patient is elsewhere
Modifier 95	Qualifying synchronous audio-video services when required
Modifier 93	Qualifying audio-only services when permitted and required

Medicare, Medicaid, Medicare Advantage, and commercial plans may have different telehealth requirements. Verify the applicable date-of-service rules before claim submission.

Same-day restrictions: CMS NCCI policy and CPT guidelines prohibit reporting office E/M codes 99202–99215 with CPT 90791 or 90792 on the same date of services by the same provider. 90791 must be reported once per day.

90791 also cannot be reported with psychotherapy codes 90832–90838 or crisis codes 90839/90840 on the same date. Interactive complexity (+90785) may be added when documentation supports it.

Practices should review applicable NCCI edits and payer policies before reporting additional services or applying modifiers.

CPT 90791 Compared With Related Psychiatric Codes

CPT code	Service	Coding distinction
90791	Psychiatric diagnostic evaluation	Without medical E/M services
90792	Psychiatric diagnostic evaluation	Includes medical services
90832	Individual psychotherapy	30-minute psychotherapy code
90834	Individual psychotherapy	45-minute psychotherapy code
90837	Individual psychotherapy	60-minute psychotherapy code
99202–99205	New-patient office E/M	Selected using applicable MDM or time rules

CPT 90791 and 90792 distinguish psychiatric diagnostic evaluations based on whether medical services are included. Psychotherapy codes describe therapeutic treatment rather than the comprehensive diagnostic evaluation, while office E/M codes represent qualifying medical visits.

Code selection must follow the documented clinical service and applicable payer rules.

CPT 90791 Reimbursement Considerations

Reimbursement varies by payer, geographic locality, provider type, and place of service.

Medicare rates can be checked through the CMS Physician Fee Schedule. Medicaid and commercial plans establish their own reimbursement policies and contracted allowances.

For covered Medicare services, eligible independently enrolled MFTs and MHCs are paid at 75% of the clinical psychologist Physician Fee Schedule amount.

Practices should verify current fee schedules, patient eligibility, and authorization requirements instead of relying on a fixed national reimbursement estimate.

Preventing CPT 90791 Claim Denials

Before submitting a psychiatric diagnostic evaluation claim, billing teams should review five common risk areas:

1. Insufficient documentation: Confirm that clinical findings, diagnostic impressions, and treatment recommendations support the evaluation.
2. Incorrect code selection: Distinguish 90791 from medical psychiatric evaluations, psychotherapy, and E/M services.
3. Unsupported repeat assessments: Document medical necessity and verify payer frequency limitations.
4. Provider eligibility errors: Confirm licensing, enrollment, and payer credentialing requirements.
5. Telehealth reporting errors: Validate the communication method, POS code, modifiers, and coverage requirements.

These checks help identify coding and documentation discrepancies before claims are submitted.

BillingFreedom Support for Psychiatric Diagnostic Evaluation Claims

Accurate CPT 90791 reporting requires appropriate coding, clinical documentation, and payer verification. BillingFreedom supports behavioral health practices with medical billing, claims management, and denial resolution to help maintain consistent revenue cycle workflows.

FAQ's

Is 90791 a time-based code?

No. Its descriptor has no minimum or maximum time.

Can 90791 be billed with 90834 on the same day?

No. CPT and NCCI prohibit psychotherapy on the same date as 90791.

Can 90791 be billed via telehealth?

Yes. Use POS 10 or 02 and the modifiers the payer requires.

How often can 90791 be billed?

Once per day, and generally once at the start of care unless a reassessment is medically necessary. 

Official References

• CMS Medicare Billing and Coding Article A57480
• CMS Medicare Physician Fee Schedule
• CMS 2026 NCCI Policy Manual, Chapter XI
• CMS Medicare Telehealth Services