90791 is one of the most frequently-billed CPT codes. Used by psychotherapists, it’s billed for the initial intake appointment for each new client at the start of therapy. In certain cases, it can also be used later in treatment.

Most therapists probably feel very confident in how they are using this code for their billing.

But some therapists are using this code too often, or inappropriately. This can send a red flag to the insurance plan, and lead to an audit, a claim denial, or even a request for money to be refunded to the plan.

And some therapists don’t use this code at all, billing first sessions with timed psychotherapy CPT codes like 90834, 90837, and 90847. In doing so, they may be missing out on deserved reimbursement, since 90791 is usually paid at a higher rate than other psychotherapy codes.

So, let’s review and take a closer look at the proper use of this code.

What is a 90791? A CPT code is the 5-digit code that tells the insurance plan what service you provided. 90791 is the CPT code for a “psychiatric diagnostic evaluation.” Don’t be intimidated by the description: You don’t have to be a psychiatrist or give your client some type of formal written evaluation. Think of it simply as the code to use for the first session with your client(s) where you are taking a history and gathering data so you can formulate your tentative diagnoses, determine medical necessity for treatment, and develop your treatment plan. Information may also be obtained from family members, other providers, or other sources.

90791 is defined by Medicare as an integrated biopsychosocial assessment that includes taking a complete medical and psychiatric history (including past, family, and social history), a mental status exam, establishing a tentative diagnosis, and evaluating the client’s ability and willingness to participate in the proposed treatment plan.

Is authorization required? CPT Code 90791 usually doesn’t require prior authorization, though it is wise to check with the health plan.

Are there time requirements? Unlike other timed psychotherapy codes (90832, 90834, 90837, etc.), there are no time requirements in the CPT Code Manual for 90791. However, the Centers for Medicare Services have specific requirements that require CPT Code 90791 to be at least 16 minutes and not more than 90 minutes in the designated session time, with 60-minutes being the typical standard.

Should I use it for all first sessions, even with couples or families? Yes! The only time you might not use it for an intake session is if the client is in such crisis when they come to session you aren’t able to complete a basic history or diagnostic interview (then you would use the Crisis Codes 90839 and possibly 90840).

Can I bill insurance for multiple 90791 sessions at the start of treatment? This will depend on the health plan and the client’s policy. I would recommend you only bill one 90791 at the start of treatment even if you did separate intake sessions with family members, unless you have clear information that your client’s policy will cover more than one.

Can I use the code again later in treatment? Again, this will vary depending on the client’s plan, so look into their client’s policy. Some private insurance plans including Aetna allow CPT Code 90791 to be used once in 6 months (click here for Aetna’s announcement), but don’t give guidance on appropriate use.

Some therapists I know use this code every time they update the client’s treatment plan in session with the client. I worry that when a 90791 pops up on a claim mid-treatment for no apparent reason it may trigger a red flag at the insurance plan. Wanting to avoid a possible treatment review or audit, in my practice I used 90791 only at intake or after a client had returned to treatment after being away for 6 months or more, thereby requiring a reassessment.

Medicare seems to take a similar approach: “The same provider may repeat [the 90791] for the same client if an extended hiatus in treatment occurs, if the patient requires admission to an inpatient status for a psychiatric illness, or for a significant change in mental status requiring further assessment. An extended hiatus is generally defined as approximately 6 months from the last time the patient was seen or treated for their psychiatric condition. A psychiatric diagnostic evaluation may also be utilized again if the patient has a previously established neurological disorder or dementia and there has been an acute and/or marked mental status change, or a second opinion or diagnostic clarification is necessary to rule out additional psychiatric or neurological processes, which may be treatable.” (for citation, click here)

Can I bill for a 90791 when a client changes their insurance plan? No. This change didn’t require you to do a fresh diagnostic evaluation or history-taking.

How is it paid by insurance plans? CPT Code 90791 usually pays more than CPT Codes 90834 (45-minute psychotherapy), 90837 (60-minute psychotherapy), or 90847 (50-minute family or couples sessions). But rates will vary based on the health plan, the location, demographic demand, the license of the provider, and if raises have been negotiated.

Who can bill this code? CPT Code 90791 can be billed by a variety of mental health clinicians, including Licensed Clinical Social Workers, Licensed Mental Health Counselors, Licensed Professional Counselors, Licensed Marriage and Family Therapists, and Clinical Psychologists. Psychiatrists and other medical professionals will typically use the 90792 code.

What documentation is needed for the 90791 session? This will also vary with the health plan. But Medicare’s documentation requirements for a 90791 session are very similar to what many health plans require: Along with the basic requirements for any session note, the medical record should indicate:

• The reason for the evaluation/client’s chief complaint
• Your diagnostic impression and the symptoms and impairment which led to this impression
• Referral source (if applicable)
• History of present illness
• Past psychiatric history
• Significant medical history and current medications
• Social and family history
• Mental status exam
• Client strengths/liabilities
• Your treatment plan (including methods of therapy, anticipated length of treatment, and a description of the planned measurable and objective goals related to expected changes in behavior or thought processes)
• When family or other informants are interviewed in lieu of the patient, document the specific reason(s) for not evaluating the client.
• And as for any session note, don’t forget to document the ACTUAL therapy start and stop time, not just the scheduled start and stop time.

Intake sessions aren’t easy for veteran therapists or newbies. Build your confidence in these sessions – check out my pre-recorded training “The First Session: Juggling Clinical and Administrative Tasks” – click here

Do you worry that your notes couldn’t pass an audit? Build your confidence in your documentation – take my pre-recorded documentation courses “What’s Missing From Your Charts: Writing Great Notes” and “How to Write a 10-Minute Treatment Plan” – click here