90791 or 90837: Which Code Fits the Session?
90791 or 90837? CPT 90791 is a psychiatric diagnostic evaluation. CPT 90837 is individual psychotherapy lasting 53 minutes or more. One assesses a patient and the other treats one, so the visit decides the code, not the rate. This guide covers the difference, the same-day rule, documentation and what changes for psychotherapists and psychiatrists. Full code references: diagnostic evaluation guide and individual psychotherapy guide.
What is the difference between 90791 and 90837?
| Code | What it is | Time |
|---|---|---|
| 90791 | Psychiatric diagnostic evaluation (no medical services) | No time range defined in CPT |
| 90837 | Individual psychotherapy | 53 minutes or more of face-to-face time |
Both codes appear in the Medicare Mental Health booklet (MLN1986542). More detail: CPT 90791 and CPT 90837.
Which pays better, 90791 or 90837?
Reimbursement comes from each payer’s fee schedule and varies by year, plan and state, so this page does not quote rates. Look up both codes in the Medicare Physician Fee Schedule look-up tool and in your commercial payers’ schedules. Then bill what happened in the room. A first assessment is 90791. A therapy session of 53 minutes or more is 90837.
Can you bill 90791 and 90837 on the same day?
Under the NCCI Policy Manual, Chapter XI (2026), psychotherapy codes are not reported with 90791 or 90792 on the same date. If an intake runs long, bill the evaluation and document the face-to-face time. Do not split one visit into two codes to raise payment.
How long can a session run before it needs extra support?
Medicare contractor article A57480 says a session over 90 minutes is paid only if the record shows the face-to-face time and why the extra time was needed. 90837 has no upper limit in CPT, but payers may question long sessions, so record start and end times every time.
What to document for 90791 or 90837
- 90791: referral reason, history, mental status, diagnosis and plan
- 90837: start and end time, interventions, patient response and progress toward goals
- Both: date, provider credentials and signature, and medical necessity
See the documentation requirements guide and contractor article A57520 for the Medicare wording.
What psychotherapists and psychiatrists should know about 90791 or 90837
- Psychotherapists: use 90791 to open care, then 90837 only when the session reaches 53 minutes.
- Psychiatrists: if the evaluation includes medical services, the code is 90792. With an E/M, psychotherapy is billed as an add-on (+90833, +90836, +90838) rather than 90837. See 90791 vs 90792.
90791 or 90837 and Medicare, private payer and state rules
- Medicare (CMS.gov): the sources above; contractors can differ.
- Private payers: set their own frequency, authorization and long-session edits.
- State law and Medicaid: varies by state. Never apply one state’s rule to another.
90791 or 90837: common questions
What is the difference between 90791 and 90837?
90791 is a diagnostic evaluation used to assess. 90837 is individual psychotherapy of 53 minutes or more, used to treat.
Which pays better, 90791 or 90837?
It depends on each payer’s current fee schedule. Rates change by plan, year and state, and the type of visit sets the code.
Can I bill 90791 and 90837 together?
Not on the same date under Medicare’s NCCI manual. Psychotherapy codes are not reported with 90791 or 90792 on the same date.
What if a 90837 session runs over 90 minutes?
Medicare contractor article A57480 says the record must show the face-to-face time and why extra time was needed. Document start and end times.
Common 90791 or 90837 billing mistakes
- Billing 90837 when the session ran under 53 minutes
- Billing 90791 and 90837 on the same date under Medicare rules
- Leaving out start and end times on long sessions
- Splitting one visit into two codes to raise payment
- Repeating 90791 without a break, admission or significant change the payer would accept
Monday-morning 90791 or 90837 checklist
- Check recent 90837 notes for documented times of 53 minutes or more
- Review any session over 90 minutes for documented time and medical necessity
- Confirm each intake note supports a diagnostic evaluation
- Ask each payer how it handles repeat evaluations and long sessions
- Fix same-date 90791 and psychotherapy claims before they are denied
How MCM South handles these claims
MCM South Medical Billing Service works only in mental and behavioral health, with solo and mid-size practices run by psychotherapists and psychiatrists. We verify insurance benefits, submit claims electronically, follow up on denied and rejected claims, file secondary claims and bill out-of-network claims for clients. Clean code selection and complete notes at the front end keep that work simple, so most of the checklist above is what we review first. If you want a second pair of eyes on 90791 or 90837 in your own claims, we can walk through it with you.
Where this applies
MCM South Medical Billing Service bills mental and behavioral health claims for psychotherapists and psychiatrists in Georgia, Massachusetts, Connecticut, Texas, Florida, New York, Colorado, Tennessee, North Carolina and Illinois. Payer rules differ by state and by plan, so confirm each rule with the payer before you bill. Ready for help? Get a free quote or schedule a consultation.
For quick reference only: verify against the current AMA CPT manual and each payer’s policy before billing. Operational billing guidance, not legal advice. Current as of last search (sources checked 9/29/26).
