CPT Code 90791: Guide to Psychiatric Diagnostic Evaluation and Billing

A therapist completes a new patient intake and then moves into psychotherapy because the patient is ready to start treatment. For a Medicare patient, the claim was later denied because both services were reported for the same date.

The care may have been appropriate. The billing did not fit the coding rules. With 90791, what matters is the service you performed, what the note supports, and what else was billed that day.

Key Takeaways

• CPT 90791 reports a psychiatric diagnostic evaluation without medical E/M services.
• Under Medicare NCCI rules, 90791 is not separately reportable with psychotherapy on the same date.
• Repeat evaluations may be appropriate when a new episode, major clinical change, readmission, or another diagnostic need supports medical necessity.
• Medicare recognizes 90791 as a telehealth service. POS and modifier rules depend on the patient’s location and how the visit is delivered.
• The note should show why the evaluation was needed, what you assessed, your diagnostic impression, and the treatment plan.

What Is CPT Code 90791 Used For?

CPT 90791 is used for a psychiatric diagnostic evaluation without medical evaluation and management services. It supports the biopsychosocial assessment used to understand the patient’s presentation, establish or clarify a diagnosis, and plan treatment. CMS distinguishes it from 90792, which includes medical E/M work.

Do not select 90791 simply because an appointment is labeled “intake” or lasts an hour. The work performed and documented should support the diagnostic evaluation.

What Does CPT 90791 Cover?

A 90791 evaluation may include the reason for referral, current symptoms, psychiatric history, relevant medical history, family and social history, mental status findings, diagnostic reasoning, and treatment planning. Family members or other sources may also contribute relevant information.

90791 does not include medical E/M work. If a physician or other qualified practitioner performs a psychiatric diagnostic evaluation with medical assessment, CMS guidance says 90792 or an appropriate E/M code may be used, depending on the service performed.

CPT 90791 vs. 90792 and Psychotherapy Codes

Code	Service	Time rule	Medical E/M included
90791	Psychiatric diagnostic evaluation	No CPT time threshold	No
90792	Psychiatric diagnostic evaluation with medical services	No CPT time threshold	Yes
90832	Individual psychotherapy	16 to 37 minutes	No
90834	Individual psychotherapy	38 to 52 minutes	No
90837	Individual psychotherapy	53 minutes or more	No

CMS separates 90791 and 90792 from timed psychotherapy services within the broader set of psychiatric CPT codes. The decision between 90791 and 90792 is not based on visit length. It depends on whether medical E/M work was part of the diagnostic evaluation.

Who Can Bill CPT 90791?

Billing depends on professional licensure, state scope of practice, payer enrollment, and the service performed.

For Medicare, eligible mental health professionals include physicians, clinical psychologists, clinical social workers, clinical nurse specialists, nurse practitioners, physician assistants, marriage and family therapists, and mental health counselors, subject to Medicare qualifications and state scope rules.

Do not choose 90791 or 90792 from the provider’s title alone. The code should follow the service that was actually performed.

Does CPT 90791 Have a Time Requirement?

No. CPT 90791 is not a timed code.

One Medicare LCD describes 45 minutes to one hour as a standard length for a psychiatric diagnostic evaluation, while clearly stating that these are not timed codes. That contractor guidance should not be turned into a national 16-minute or 60-minute threshold.

Document session length when the payer or your policy requires it, but do not apply psychotherapy time thresholds to 90791.

How to Handle Common 90791 Edge Cases

The Evaluation Is Not Finished 

Some patients need more than one encounter to complete the initial diagnostic evaluation. Medicare contractor guidance recognizes this in certain cases, including some children and older adults. If another diagnostic visit is needed, document why the evaluation could not reasonably be completed in one encounter.

Only a Parent, Caregiver, or Other Informant Attends 

Family members and other sources can contribute to the evaluation. Medicare coverage guidance also recognizes limited situations in which an informant may be interviewed instead of the patient.

If the patient is not directly evaluated, explain why in the record and check the payer’s policy before billing.

The Patient Presents in Crisis 

A distressed patient does not automatically qualify for crisis psychotherapy.

If the service actually meets the requirements for psychotherapy for crisis, report the appropriate crisis service rather than 90791 for that date. Medicare NCCI does not allow crisis psychotherapy to be separately reported with 90791 or 90792 on the same date.

The Patient Does Not Show 

Do not bill 90791 for a cancellation or no-show when the psychiatric diagnostic evaluation was not provided.

The Patient Returns After a Gap 

A repeat evaluation may be reasonable for a new episode, psychiatric admission or readmission, significant mental status change, or a new diagnostic question.

There is no single national six-month rule for every patient or payer. Medicare contractor utilization rules vary, and the record should support why another diagnostic evaluation was medically necessary.

CPT 90791 Documentation Checklist

The note should make your diagnostic work easy to follow. Medicare contractor requirements vary, so this should not be treated as a universal payer checklist.

A well-supported 90791 record should generally include:

• Reason for referral or evaluation
• Current symptoms and relevant history
• Psychiatric and relevant medical history
• Family and social history when clinically relevant
• Mental status findings
• Safety or risk findings when clinically indicated
• Diagnostic impression or working diagnosis, plus the appropriate mental health ICD-10-CM code 
• Treatment recommendations or initial plan
• Session date and length when required
• Clinician identity, credentials, and signature

CMS coverage guidance expects the record to support medical necessity and show the content and clinical outcome of the diagnostic assessment.

A long intake form is not enough if the record never shows what you concluded or how the assessment leads to the treatment plan.

Billing and Bundling Rules for CPT 90791

Medicare NCCI rules state that 90791 and 90792 are not separately reportable with individual, group, family, crisis, or other psychotherapy on the same date. Office E/M codes such as 99202 through 99215 also are not reported with these psychiatric diagnostic codes.

Review the claim when 90791 appears on the same date as 90832, CPT 90834, 90837, crisis psychotherapy, or an office E/M service.

For Medicare, do not use a modifier simply to bypass this same-day coding policy. For other payers, verify the applicable coding edits and billing requirements.

When Does 90785 Apply With 90791?

Interactive complexity code 90785 may be added when a qualifying communication problem makes the psychiatric service more complex.

CMS examples include maladaptive communication among participants, caregiver behavior that interferes with treatment, mandated reporting tied to a sentinel event, or adaptations needed to overcome a significant communication barrier. A parent, guardian, or interpreter being present does not by itself establish interactive complexity.

CPT 90791 Telehealth Billing Rules

CMS identifies 90791 as a Medicare telehealth service.

Telehealth Situation	Medicare Billing
Patient receives telehealth at home	POS 10
Patient receives telehealth somewhere other than home	POS 02
Real-time audio and video	Modifier 95
Eligible real-time audio-only service	Modifier 93

For Medicare professional claims, POS 10 is paid at the nonfacility rate and POS 02 at the facility rate. CMS claims guidance pairs modifier 95 with audio and video telehealth and modifier 93 with eligible audio-only services.

Medicare permanently allows qualifying behavioral and mental health telehealth through audio-only technology when applicable requirements are met. The practitioner must be capable of furnishing audio and video, while audio only may be used when the patient is not capable of, or does not consent to, using video. Verify the requirements in effect on the date of service.

The Medicare in-person visit requirement tied to behavioral and mental health telehealth is also delayed through December 31, 2027. Verify the rules in effect for the date of service.

Also confirm the patient’s physical location and the licensure requirements that apply where the patient is located.

Practice Level Audit Checks for CPT 90791

Before a payer review, look for repeat evaluations without a clear reason, notes that do not show diagnostic work, same-day psychotherapy or E/M conflicts, routine 90785 use without support, telehealth billing mismatches, copied notes, and gaps between the diagnosis and treatment plan.

CMS notes that compliance with psychiatric coverage rules may be reviewed through medical review and claims analysis.

The goal is not a longer intake. It is a record that clearly links the presenting problem, assessment, diagnosis, and plan.

Make the First Visit Work Better for the Rest of Care

A new patient visit creates work that continues after the appointment ends. Forms need to be organized, treatment needs carried forward, follow-ups scheduled, coverage checked, and the patient kept informed about what happens next.

Vozo EHR brings those steps into one behavioral health platform, so your team can move from the first appointment into ongoing care without rebuilding the workflow in separate systems.

• Behavioral health forms give clinicians ready-to-use options for intake, history, mental status exams, evaluations, risk checks, and safety planning.
• Treatment plans and clinical dashboards keep assessments, tasks, medications, schedules, and next steps accessible from the patient record.
• Scheduling, reminders, and secure messaging help staff manage follow-up care without relying on separate tools.
• Patient portal access gives patients one place to complete forms, communicate with the practice, and manage payments.
• Eligibility and billing tools help staff check coverage and manage the administrative work that follows the visit.
• An EHR with telehealth keeps virtual appointments within the same workflow used for ongoing behavioral health care.

The first appointment should set up the next step in care, not create another round of administrative work. A connected system helps your team carry that information forward instead of entering and checking it again.

Frequently Asked Questions

Can I bill 90791 and a therapy session on the same day?

Under Medicare NCCI rules, 90791 and 90792 are not separately reportable with individual, group, family, crisis, or other psychotherapy services on the same date. That includes 90832, 90834, and 90837. Other payers may use their own edits, so check the patient’s plan before assuming the Medicare rule applies without change.

How many times can I bill 90791 for the same patient?

There is no universal CPT rule limiting 90791 to one service for the entire course of care. Repeat evaluation may be needed for a new episode, readmission, major mental status change, or new diagnostic question. Medicare contractor limits vary, so document the reason for reassessment and verify the payer policy that applies.

Does CPT 90791 have a minimum session length?

No. CPT 90791 is not a timed code and does not have a 16-minute CPT minimum. Some Medicare contractor guidance describes about 45 minutes to one hour as a standard session length, but that is not a national CPT threshold. Choose the code based on the service performed and document session length when required.

Can CPT 90791 be billed through telehealth?

Yes. CMS identifies 90791 as a Medicare telehealth service. For professional Medicare claims, POS 10 applies when the patient is at home and POS 02 when the patient is elsewhere. Modifier 95 identifies real-time audio and video, while modifier 93 identifies an eligible real-time audio-only service.

What is the difference between 90791 and 90792?

Both codes report a psychiatric diagnostic evaluation. The difference is medical E/M work. 90791 does not include medical E/M services, while 90792 includes medical services as part of the evaluation. The clinician’s title alone does not decide the code. Choose the service that matches the work performed and documented.

Why might a 90791 claim be denied?

A denial may result from an incompatible same-day service, payer frequency rules, authorization requirements, telehealth claim errors, eligibility problems, or a record that does not support the evaluation. Start with the remittance reason and payer policy. Do not change the code simply to obtain payment if another code does not match the service.

Sources

Centers for Medicare & Medicaid Services (CMS), Local Coverage Article: Billing and Coding, Psychiatry and Psychology Services (A57480) https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleId=57480 

Centers for Medicare & Medicaid Services (CMS), Medicare Benefit Policy Manual, Chapter 15, Covered Medical and Other Health Services https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/bp102c15.pdf

Centers for Medicare & Medicaid Services (CMS), Medicare Coverage of Telehealth Services https://www.cms.gov/medicare/coverage/telehealth