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Mental Health Billing Guide 2026: CPT 90837 vs 90834, Modifiers & Common Denials

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Mental health billing looks simple on paper: a handful of psychotherapy codes, mostly time-based, billed week after week. In practice, it's one of the most denial-prone specialties in medicine. Time thresholds are strict, payers watch 90837 closely, telehealth rules differ by payer, and session limits and authorizations can quietly stop payment mid-treatment. This guide walks therapists, psychologists and group practice owners through the codes, the rules and the fixes that keep behavioral health claims paid in 2026.

Note: CPT® codes are maintained by the AMA, and payer policies change. Always confirm current rules with your Medicare Administrative Contractor (MAC), state Medicaid program and commercial payer contracts.

Core Therapy Billing Codes and Time Thresholds

Most psychotherapy codes are time-based, and CPT's general rule is that a unit of time is reached once you pass the midpoint. That's where the familiar ranges below come from. Time means face-to-face (or synchronous telehealth) time with the patient and/or family, not documentation time.

Code Description Time rule
90791 Psychiatric diagnostic evaluation (no medical services) Not time-based; usually once per episode of care
90792 Psychiatric diagnostic evaluation with medical services Not time-based; for prescribers (MD, DO, NP, PA)
90832 Psychotherapy, 30 minutes 16–37 minutes
90834 Psychotherapy, 45 minutes 38–52 minutes
90837 Psychotherapy, 60 minutes 53 minutes or more
90846 Family psychotherapy without the patient present, 50 minutes 26 minutes or more
90847 Family psychotherapy with the patient present, 50 minutes 26 minutes or more
90853 Group psychotherapy (other than multiple-family group) Per session, per patient
+90785 Interactive complexity (add-on) Not time-based
90839 Psychotherapy for crisis, first 60 minutes 30–74 minutes
+90840 Psychotherapy for crisis, each additional 30 minutes Add once you reach 75 minutes, then per 30 more

A few rules that trip practices up:

  • Under 16 minutes is not billable as psychotherapy.
  • Prescribers who do E/M plus therapy on the same day bill the E/M code plus add-on 90833, 90836 or 90838, not 90832/90834/90837. Per CMS, time spent on the E/M can't be counted toward the psychotherapy time.
  • +90785 applies when communication factors complicate the visit, such as a caregiver whose emotions interfere with care, or the need for play equipment or an interpreter-like device to communicate. It can be added to 90791, 90792, the psychotherapy codes and 90853, but not to family therapy (90846/90847) or crisis codes. Translation or interpretation alone does not qualify.
  • Crisis codes (90839/90840) are reported by themselves. CMS states they may not be billed with 90791, 90792, 90832–90838 or 90785 for the same session. Document the urgent assessment, the mental status, and the de-escalation or safety planning work.
  • Group therapy (90853) is billed once per patient in the group. Each patient needs their own note.

CPT 90837 vs 90834: Which Should You Bill?

The CPT 90837 vs 90834 choice is a time question, not a quality question:

  • 38 to 52 minutes → 90834
  • 53 minutes or more → 90837

Because 90837 pays more and is the code payers see most often in outlier reports, it gets extra scrutiny. Several commercial payers have run post-payment reviews or sent letters to clinicians who bill 90837 for most of their sessions. That doesn't make 90837 risky when it's accurate. It means your documentation has to prove it.

What a defensible 90837 note includes:

  1. Exact start and stop times (e.g., 2:02–2:58 PM) or total minutes. "60 min" written on every note looks templated.
  2. Medical necessity for the longer session: symptom severity, trauma processing, a treatment-plan goal that needs extended time, or a recent clinical change.
  3. Interventions used (CBT, EMDR, DBT skills, etc.) and the patient's response.
  4. A link to the treatment plan and diagnosis.
  5. Plan for the next session.

Practical tips:

  • If your standard session is 50 minutes, bill 90834. Don't round up a 50-minute session to 90837.
  • If you schedule 60-minute sessions, protect the time: a late start that brings you to 51 minutes is a 90834.
  • Watch your mix. A mix that is nearly all 90837 is not wrong in itself, but it draws attention, so make sure every note supports it.
  • Check payer policies. Some plans require prior authorization for 90837 or for sessions beyond a certain number.
  • Sessions over 90 minutes (90837 plus prolonged service codes, where the payer allows them) need clear documentation of the face-to-face time and why it was medically necessary.

Telehealth Mental Health Billing: POS 02 vs 10 and Modifiers

Telehealth is now a permanent part of behavioral health care, and telehealth mental health billing mostly comes down to two fields: place of service (POS) and modifier.

Place of Service

  • POS 10: Telehealth provided in the patient's home. For Medicare, this has been paid at the non-facility rate since January 1, 2024.
  • POS 02: Telehealth provided somewhere other than the patient's home (for example, a clinic or school). Medicare pays it at the facility rate.

According to CMS, POS 02 and POS 10 are the only valid POS codes for Medicare telehealth claims. Some commercial and Medicaid plans still ask you to bill the POS where the visit would have happened (often POS 11, office) plus a modifier. Check each contract.

Modifiers

Modifier Meaning Where it's used
95 Synchronous audio-video telehealth Medicare and many commercial plans
93 Audio-only telehealth Medicare and some commercial plans
FQ Audio-only service Medicare, required for FQHCs and RHCs
GT Interactive audio-video (older modifier) Mostly retired for Medicare (still used for critical access hospital method II); some Medicaid and commercial plans still require it

Audio-only: CMS allows audio-only behavioral health services to patients at home when the clinician can do video but the patient can't or won't use it. Document that reason in the note. Under current law, Medicare's broader home audio-only flexibilities run through December 31, 2027.

Other telehealth checks: Make sure you're licensed in the state where the patient is located on the day of the visit, document the patient's location and consent, and confirm the plan covers telehealth for that code.

Prior Authorization and Session Limits

Behavioral health benefits vary widely, and authorization problems are a leading cause of lost therapy revenue.

  • Verify eligibility and benefits before the first session and periodically after. Note whether behavioral health is carved out to a separate managed behavioral health organization (MBHO). Many plans route mental health claims to a different payer ID than medical claims.
  • Track session limits. Some plans cap visits per year or require re-authorization after a set number of sessions.
  • Know which codes need authorization. Requirements often apply to 90837, intensive outpatient programs, psychological testing and higher-frequency treatment.
  • Track auth numbers, start/end dates and approved units in your practice management system so the claim matches the authorization.
  • Request extensions early with updated treatment-plan progress, not after the last approved visit.

Note that federal mental health parity rules generally prohibit plans from imposing stricter limits on mental health benefits than on comparable medical benefits. If a limit seems out of line, it can be worth asking the plan to justify it.

Common Mental Health Billing Denials and How to Fix Them

Denial Typical cause Fix
CO-197 — Precertification/authorization absent No auth, expired auth, or units exceeded Track auths by date and units; request retro-auth where allowed; appeal with documentation
CO-16 — Missing or invalid information Missing NPI, taxonomy, rendering provider, modifier or POS Scrub claims before submission; correct and resubmit
CO-50 — Not medically necessary Thin notes or diagnosis that doesn't support the service Link each note to the diagnosis and treatment plan; appeal with records
CO-97 — Bundled service Two codes billed that can't be billed together (e.g., crisis codes with routine psychotherapy) Follow CMS/NCCI pairing rules; bill only one
CO-119 — Benefit maximum reached Session limit hit Check visit counts at intake; request an extension or set up a patient payment plan
CO-29 — Timely filing expired Claim submitted late Submit within days; track each payer's filing limit
Wrong payer / carve-out Claim sent to the medical plan instead of the MBHO Verify behavioral health payer ID at eligibility check
Provider not credentialed / out of network Clinician not enrolled with the plan Complete enrollment before seeing patients under that plan
Telehealth POS/modifier mismatch Wrong POS or missing 95/93 Build payer-specific telehealth rules into your claim scrubber

Most of these are preventable at the front end. The rest need a fast, organized appeal process. If denials are piling up, a structured denial management process usually recovers far more than ad hoc resubmissions.

Credentialing and CAQH Basics for Therapists

You can't get paid in network until you're credentialed and enrolled with each payer. For most behavioral health clinicians:

  1. Get an individual NPI (Type 1), and a group NPI (Type 2) if you bill as a group.
  2. Create and complete your CAQH ProView profile. Most commercial payers pull credentialing data from CAQH. Upload your license, malpractice insurance, education and work history, and authorize each payer to view your profile.
  3. Re-attest in CAQH every 120 days. A lapsed attestation can stall applications and re-credentialing.
  4. Enroll in Medicare through PECOS if you see Medicare patients. Since January 1, 2024, marriage and family therapists (MFTs) and mental health counselors (MHCs, including LPCs) can enroll and bill Medicare directly.
  5. Apply to each commercial and Medicaid plan and track every application. Timelines often run for months, so start before you need the contract.
  6. Link rendering providers to your group with each payer so claims don't deny for the wrong provider.

Our credentialing services handle CAQH maintenance, PECOS and payer enrollment for individual clinicians and group practices.

When Should a Mental Health Practice Outsource Billing?

Many solo therapists start by billing themselves. It's usually time to consider outsourcing when:

  • You spend more than a few hours a week on claims, calls and appeals instead of seeing patients.
  • Denials or unpaid claims are growing, or A/R over 90 days keeps climbing.
  • You're adding clinicians, payers or states, and credentialing is falling behind.
  • Authorization and session-limit tracking is happening in a spreadsheet, or not at all.
  • You've added telehealth across multiple payers with different POS and modifier rules.

If you're comparing options, our guide to how much medical billing costs breaks down pricing models and hidden fees. You can also see how we support therapists and group practices on our behavioral health billing page.

Frequently Asked Questions

What is the difference between CPT 90837 and 90834?

Both are individual psychotherapy codes. 90834 is billed for 38–52 minutes of psychotherapy and 90837 for 53 minutes or more. Payers look closely at 90837, so document exact times and medical necessity.

Can I bill 90837 for a 50-minute session?

No. A 50-minute session falls in the 38–52 minute range, so it should be billed as 90834. 90837 requires at least 53 minutes of psychotherapy time.

Should I use POS 02 or POS 10 for telehealth therapy?

For Medicare, use POS 10 when the patient is at home and POS 02 when the patient is somewhere else, such as a clinic. Some commercial and Medicaid plans have their own rules, so check each payer.

Which modifier do I use for telehealth mental health services?

Medicare and many commercial plans use modifier 95 for audio-video visits and 93 for audio-only. FQHCs and RHCs use FQ for audio-only. Some Medicaid and commercial plans still require GT, so confirm with each payer.

When can I bill the interactive complexity add-on 90785?

When specific communication factors complicate the visit, such as caregivers who interfere with care or a patient who needs play equipment or other devices to communicate. It can't be billed with family therapy or crisis codes, and interpreter use alone doesn't qualify.

How do I reduce mental health billing denials?

Verify eligibility and behavioral health carve-outs before the first visit, track authorizations and session limits, document exact session times, use the right POS and modifiers, keep CAQH current, and appeal denials quickly.

Get a Free Mental Health Billing Audit

Not sure whether your coding, telehealth claims or authorizations are costing you money? 24Front Billing Services offers U.S. behavioral health practices a free billing audit that reviews your code mix, denials and aging A/R, and shows you where revenue is slipping.

Learn more about our behavioral health billing, denial management and credentialing services, or request your free billing audit today.

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