CPT 90791 Billing Guidelines: The Complete 2026 Guide

What Are the Billing Guidelines for CPT 90791?

CPT 90791 is the procedure code for a psychiatric diagnostic evaluation performed without medical services. It is billed once per patient, per provider, per episode of care, and it covers the initial comprehensive intake where the clinician assesses psychiatric history, current symptoms, psychosocial factors, and diagnostic impressions to establish a treatment plan. In 2026, the national Medicare non-facility reimbursement for 90791 falls in the range of approximately $174 to $178, depending on geographic locality adjustments.

• Who can bill it: Psychiatrists, psychologists, licensed clinical social workers, licensed professional counselors, licensed marriage and family therapists, and psychiatric mental health nurse practitioners can all bill 90791, subject to state scope-of-practice laws and individual payer credentialing requirements.
• 90791 vs 90792: 90791 covers the diagnostic evaluation only. 90792 adds medical services such as a physical examination or medication review. Use 90791 when the intake does not include any medical service component.
• Common denial trigger: Billing 90791 more than once per episode of care without documented clinical justification for a new evaluation is the most frequent reason payers deny this code, followed closely by incomplete documentation of the diagnostic assessment.

What CPT 90791 Covers

CPT 90791 reports a psychiatric diagnostic evaluation that does not include medical services. The American Medical Association defines it as a comprehensive assessment of a patient’s mental health condition, including presenting symptoms, psychiatric history, psychosocial history, and clinical findings that lead to a diagnosis and an initial treatment plan. The evaluation is not time-based in the way psychotherapy codes are. CMS guidelines place the expected duration between 16 and 90 minutes, with most sessions running 45 to 60 minutes in practice, but the reimbursement does not change based on how long the session lasts.

The distinction that matters for billing is the boundary between 90791 and 90792. If the evaluation includes any medical service component, such as a physical examination, medication prescribing, or a review of lab results, the correct code is 90792, not 90791. Providers often come to us after receiving denials on intake claims, and the most frequent cause we see is a clinician who performed a medication review during the intake but billed 90791 instead of 90792. That single coding decision costs the practice money in two directions: the 90791 claim gets denied or audited, and the higher-reimbursing 90792 was never billed at all.

90791 applies across all practice settings, including outpatient clinics, private practices, community mental health centers, inpatient facilities, and telehealth encounters. It is not limited to a specific provider type, though payer credentialing and state licensure rules determine which clinicians can bill it independently. For a broader look at how 90791 fits alongside the full set of behavioral health procedure codes, see our guide to psychiatry CPT codes.

How Does 90791 Differ From 90792?

This is the question that generates the most billing errors on psychiatric intake claims. Both codes report an initial diagnostic evaluation, but 90792 includes medical services and 90791 does not. The clinical decision about which code to use hinges entirely on whether the encounter involved any medical service component, and that determination must be documented clearly in the record.

In our experience matching psychiatry practices with billing partners, the practices that lose the most revenue on intake claims are the ones where the clinician routinely performs medication management during the first visit but the billing team defaults to 90791 out of habit. For a closer look at how the 90792 evaluation billing process works and when it applies, see our dedicated guide.

Documentation Requirements for 90791

Documentation is where 90791 claims are won or lost. Every payer expects the clinical record to establish that a comprehensive psychiatric diagnostic evaluation was performed and that the evaluation was medically necessary. Incomplete records are the single most preventable cause of 90791 denials, and they are the issue we hear about most frequently from providers looking for billing help.

A compliant 90791 record must include the following elements. Chief complaint and reason for referral. A history of the present illness covering onset, duration, severity, and any prior treatment. A psychiatric history including past diagnoses, hospitalizations, and medication trials. A psychosocial and developmental history covering family, education, employment, substance use, and relevant social factors. A mental status examination documenting appearance, behavior, speech, mood, affect, thought process, thought content, cognition, insight, and judgment. Diagnostic impressions using current DSM-5-TR criteria with supporting ICD-10 codes. And a preliminary treatment plan that connects the diagnosis to recommended interventions.

Across the billing companies we vet for psychiatry practices, a recurring pattern separates the strong documentation from the weak: strong records tell the clinical story in a way that makes the diagnosis and treatment plan feel inevitable from the history, while weak records read like a checklist of headings with one-line answers underneath. Payers and auditors can see the difference, and so can the denial rate.

One question we hear constantly from practice managers is whether they need to document start and stop times for 90791. The code is not time-based, so time documentation is not strictly required for reimbursement. However, recording timestamps is a best practice because auditors frequently request them, and having them on the record removes a potential audit question before it starts.

Reimbursement and Payer Rules

Reimbursement for 90791 varies by payer type, geographic region, and provider credentials. Understanding the differences across Medicare, Medicaid, and commercial payers is essential for accurate revenue forecasting and for catching underpayments before they age past the appeal window.

• Medicare. Under the 2026 CMS Physician Fee Schedule, the national non-facility rate for 90791 falls approximately between $174 and $178, adjusted by the Geographic Practice Cost Index for each locality. Medicare treats 90791 as billable once per episode of care, per provider, and does not impose a hard frequency cap beyond the medical necessity requirement. Not all licensed mental health professionals can bill Medicare independently. LMFTs and LMHCs gained Medicare billing eligibility in 2024 under the Consolidated Appropriations Act, but providers must be enrolled through PECOS with a CMS-855I application before submitting claims.
• Medicaid. Medicaid rules for 90791 vary significantly by state. Some state Medicaid programs and managed care organizations require prior authorization for diagnostic evaluations, and several mandate that the evaluation be completed within a specific timeframe of enrollment in services. Always check the state-specific Medicaid provider manual and any MCO-specific behavioral health policies before billing.
• Commercial payers. Commercial plans are the most variable. Some follow standard CPT guidelines, while others carve out behavioral health benefits to a separate managed behavioral health organization with its own authorization and frequency rules. In 2026, an estimated 60 to 70 percent of commercial payers require some form of prior authorization for 90791, depending on network status and benefit design. The biggest issue we see providers run into with commercial claims is failing to verify benefits and authorization requirements before the first visit, which turns a clean intake into a denied claim that can rarely be recovered retroactively.

Common 90791 Denial Triggers and How to Fix Them

Every psychiatry practice runs into 90791 denials. The practices that keep their denial rate low treat these as process failures to be fixed, not one-off incidents to be written off. These are the denial triggers we see most often across the billing companies and providers in our network.

• Billing 90791 more than once per episode of care. Most payers allow one diagnostic evaluation per patient, per provider, per treatment episode. Rebilling without documented clinical justification for a new evaluation triggers an automatic denial. Fix: verify the patient’s claims history before billing and document the clinical basis for any repeat evaluation.
• Missing or incomplete documentation. A record that lacks the mental status exam, the diagnostic impression, or the treatment plan gives the payer grounds to deny for insufficient documentation. Fix: use a structured intake template that prompts for every required element before the note is signed.
• Billing 90791 when 90792 was performed. If the clinician conducted any medical service during the evaluation, 90791 is the wrong code. Fix: build a coding decision into the documentation workflow that flags whether medical services were rendered.
• No prior authorization obtained. Many commercial plans and some Medicaid MCOs require prior authorization for 90791. Billing without it results in a non-recoverable denial. Fix: verify authorization requirements during scheduling, before the patient arrives.
• Credentialing gaps. If the rendering provider is not credentialed with the payer, the claim will deny regardless of how clean the documentation is. Fix: confirm payer enrollment status for every provider in the practice, especially new hires and locum tenens clinicians.
• Wrong place of service code for telehealth. Telehealth evaluations require specific place of service codes and modifiers. An in-office POS code on a telehealth claim triggers a denial. Fix: use POS 10 for telehealth encounters with modifier 95 for synchronous audio-video or modifier 93 for audio-only, and verify payer-specific telehealth rules.

Telehealth Billing for 90791

CPT 90791 is on Medicare’s permanent telehealth services list, which means it can be billed for audio-video and, in many cases, audio-only encounters without a geographic restriction on the patient’s location. For 2026, Medicare telehealth billing for 90791 requires modifier 95 for real-time audio-video encounters and modifier 93 for audio-only sessions. The place of service code for telehealth is POS 10.

Commercial payers and Medicaid programs vary in their telehealth rules for psychiatric evaluations. Some commercial plans restrict audio-only intakes and require video for 90791 specifically. Several state Medicaid programs have their own modifier and POS requirements that differ from Medicare’s. In our experience matching providers with billing partners, telehealth modifier errors are one of the fastest-growing sources of 90791 denials since the pandemic-era flexibilities began sunsetting. The practices that avoid these denials verify telehealth billing rules per payer, not per assumption.

Documentation for a telehealth 90791 must include the same clinical elements as an in-person evaluation, plus the patient’s informed consent for telehealth services and confirmation that the encounter was conducted remotely. For a broader look at how telehealth modifiers interact with psychiatry’s add-on codes, see our guide to CPT 90833 add-on billing and our CPT 90834 billing guide.

90791 Best Practices for Clean Claims

The psychiatry practices that bill 90791 cleanly share a set of habits that are worth building into any behavioral health billing operation. These are the same patterns we look for when we vet the billing companies that psychiatry providers get matched with.

Verify benefits and authorization before the first visit, not after the claim denies. Use a structured intake documentation template that prompts for every required element so nothing gets missed at sign-off. Build a coding decision step into the workflow that determines 90791 versus 90792 based on whether medical services were rendered. Record start and stop times even though the code is not time-based, because auditors request them. Reconcile 90791 claims against the remittance within 48 hours of payment posting to catch underpayments and denials while appeal windows are still open. Keep credentialing current for every rendering provider and verify enrollment status when onboarding new clinicians. For practices billing add-on psychotherapy codes like 90836 alongside evaluation codes, confirm that the pairing rules are followed so neither code triggers an edit.

Frequently Asked Questions

Next Steps

• New to psychiatry billing codes? Start with our full guide to psychiatry CPT codes for an overview of every code your practice bills.
• Billing combined visits? Read our CPT 90833 add-on billing guide to understand how psychotherapy add-ons pair with E/M codes.
• Need the medical evaluation code? See our 90792 billing guide for the evaluation code that includes medical services.
• Ready to hand billing off? Get matched with vetted psychiatry billing companies that post accurately and catch the revenue others miss.