CPT Codes for Mental Health & Addiction

Mental health and addiction treatment billing runs on two code systems, not one — and the difference matters more for facilities than for anyone else. This hub covers every code family a behavioral health biller touches: psychotherapy and diagnostic CPT codes, assessment and testing codes, E/M codes, the HCPCS H-codes that drive facility billing, Medicare G-codes, and the modifiers that change how all of them pay. Each code links to a dedicated reference page with deeper billing guidance.

What CPT codes are used for mental health services?

CPT (Current Procedural Terminology) codes are five-digit numeric codes maintained by the American Medical Association; they make up Level I of the Healthcare Common Procedure Coding System (HCPCS). Mental health services concentrate in the 90785–90899 psychiatry range, the 96112–96171 testing and health-behavior range, and the 99202–99215 evaluation and management (E/M) range.

But CPT is only half the picture. HCPCS Level II codes — alphanumeric codes maintained by CMS, published in the HCPCS Level II quarterly update files ↗ — cover the services CPT doesn’t describe: detox per-diems, residential treatment days, intensive outpatient program sessions, case management, and peer support. These are the H-codes (H0001–H2037) and G-codes that dominate billing at treatment facilities.

That split defines who needs what. A solo therapist in private practice may bill five CPT codes for an entire career. A residential addiction treatment facility bills mostly H-code per-diems on institutional claims, layered with modifiers that identify the program type and staff credentials. Most CPT reference guides are written for the first audience. This one covers both — with particular depth on the facility stack that other references skip.

Psychotherapy codes (90832–90838, 90846/90847, 90853)

The psychotherapy family is the core of outpatient mental health billing. Individual psychotherapy codes are selected by time, using CPT’s time-band conventions rather than exact session length.

Two distinctions trip up new billers. First, the standalone codes (90832/90834/90837) are billed when psychotherapy is the only service; the add-on codes (90833/90836/90838) are billed alongside an E/M code when a prescriber does therapy and medical management in the same visit — never both standalone and add-on for the same encounter. Second, 90785 (interactive complexity) is an add-on for sessions complicated by communication barriers — a third party in the room, mandated reporting events, or use of play equipment with young children — not a generic “difficult session” upcharge.

Group therapy ( 90853 ) is billed per patient, per group session, and is one of the most heavily scrutinized codes in facility audits: payers look for individualized group notes, not one note copied across every attendee.

A word on 90837: because it pays more than 90834, several large payers monitor its utilization and send “outlier” letters to clinicians who bill it predominantly. The code is legitimate whenever the session genuinely runs 53+ minutes — the defense is start/stop times documented in every note, not avoiding the code. Time-band documentation is the cheapest audit insurance in outpatient behavioral health.

Psychiatric diagnostic evaluation (90791, 90792)

Every treatment episode starts with a diagnostic evaluation, and the code choice turns on whether medical services are part of it:

Most payers reimburse one diagnostic evaluation per provider per episode, with re-evaluation allowed after a significant break in treatment or a major change in condition — the exact interval is payer-specific. Medicare’s coverage rules for these services live in the Medicare Claims Processing Manual (IOM Pub. 100-04) ↗.

• 90791 — psychiatric diagnostic evaluation without medical services. Billable by the full range of licensed clinicians: psychologists, clinical social workers, licensed professional counselors, marriage and family therapists (where the payer credentials them), as well as physicians.
• 90792 — psychiatric diagnostic evaluation with medical services (for example, prescribing or medical assessment). Reserved for physicians and qualifying medical practitioners such as psychiatric nurse practitioners and physician assistants.

Crisis psychotherapy (90839, 90840)

When a session is dominated by an urgent crisis — acute suicidality, a psychiatric emergency requiring immediate stabilization — crisis codes replace the routine psychotherapy codes:

Crisis codes require documentation of the presenting emergency, the assessment performed, and the disposition — and they cannot be billed on the same day as the routine 90832-series codes by the same provider. Facilities also have HCPCS crisis options ( H2011, per 15 minutes) under many Medicaid plans.

• 90839 — psychotherapy for a crisis, first 60 minutes (covering the 30–74 minute range).
• 90840 — each additional 30 minutes of crisis work, billed as an add-on to 90839.

Assessment and testing codes (96112–96139)

Psychological and neuropsychological testing was restructured by the AMA in 2019 into a split model: evaluation services (the professional interpretation work) versus test administration and scoring (the technical work). Codes in this family that lack a dedicated reference page are shown without links.

96127 deserves a special note for facilities: it covers brief standardized instruments — the PHQ-9 or GAD-7 class of screeners — administered and scored as part of routine care, and many payers reimburse multiple units per visit when multiple instruments are used. It is one of the most under-billed codes in behavioral health.

The adjacent health behavior assessment and intervention family (96156–96171) covers psychological services addressing physical health conditions; 96164 (group health behavior intervention, per 30 minutes) is heavily used in addiction treatment, as covered in the most-billed codes section below.

E/M codes in behavioral health (99202–99215)

Evaluation and management codes are the prescriber’s workhorse — psychiatrists, psychiatric NPs, and addiction medicine physicians bill them for medication management visits, usually with a psychotherapy add-on code when therapy happens in the same encounter.

Since the AMA’s 2021 office-visit overhaul, E/M level selection is based on either medical decision making or total time on the date of the encounter — history and exam elements no longer drive the level.

A note on the prolonged-service codes 99354 and 99355: the AMA deleted this family’s use with office/outpatient E/M visits in the CPT 2023 cycle, replacing it with newer prolonged-service codes (99417 for CPT; G2212 for Medicare office visits). Claims systems still see legacy use, which is why the reference pages remain, but for current office-visit billing the 99354 family should not be reported.

• New patients: 99202, 99203, 99204, 99205 — increasing levels of medical decision making or total time.
• Established patients: 99211, 99212, 99213, 99214, 99215 — the 99213/99214 pair covers the bulk of psychiatric follow-up visits.

HCPCS H-codes for facility levels of care (H0001–H2036)

This is the section most CPT guides skip entirely — and it’s where treatment facilities live. H-codes are HCPCS Level II codes used primarily by state Medicaid programs and behavioral health carve-out payers to bill structured program services. Many commercial payers adopt them for facility contracts as well. The natural way to organize them is by level of care, loosely mapped to the SUD continuum of care.

Screening and intake

Withdrawal management (detox) — ASAM 3.7-WM/3.2-WM territory

Residential treatment — ASAM 3.1/3.5 territory

Partial hospitalization (PHP) — ASAM 2.5

Intensive outpatient (IOP) — ASAM 2.1

Outpatient and wraparound services — ASAM 1.0 and supports

Because H-codes are largely Medicaid-defined, state programs control the rates, units, and documentation rules — the same code can be a 15-minute unit in one state and a per-diem in another’s fee schedule. Always confirm against the state Medicaid fee schedule and the payer’s companion guide rather than a national reference.

• H0001 — alcohol and drug intake assessment at admission. Often billed with the HF modifier; see the most-billed codes section below.
• H0002 — behavioral health screening to determine program eligibility.
• H0031 — mental health assessment by a non-physician.
• H0049 / H0050 — alcohol/drug screening and brief intervention (Medicaid SBIRT pair).

• H0008 / H0009 — hospital-based sub-acute and acute detox.
• H0010 / H0011 — residential sub-acute and acute detox per-diems.
• H0012 / H0013 — residential program outpatient-managed detox variants.
• H0014 — ambulatory detox.

• H0017 — residential per-diem (hospital residential without room and board).
• H0018 — short-term residential per-diem.
• H0019 — long-term residential per-diem.
• H2034 — halfway house / supportive residential per-diem.

• H0035 — partial hospitalization, less than 24 hours.
• S0201 — PHP per-diem used by many commercial payers.

• H0015 — IOP per-diem for substance use programs (typically 3+ hours/day, 3+ days/week of structured programming).
• S9480 — psychiatric IOP per-diem, the commercial-payer counterpart.

• H0004 — individual counseling, billed per 15 minutes.
• H0005 — group counseling by a clinician.
• H0006 — case management.
• H0007 — crisis intervention, outpatient.
• H0020 — methadone administration and related services.
• H0038 — peer support services, per 15 minutes.
• H2011 — crisis intervention, per 15 minutes.
• H2014 — skills training and development.
• H2019 — therapeutic behavioral services, per 15 minutes.
• H2035 / H2036 — alcohol/drug treatment program, per hour and per diem.

Most-billed codes at addiction treatment facilities

Across ’s addiction treatment billing partners, three codes consistently top the volume rankings — all carrying the HF modifier that identifies a substance use program:

Providers frequently pair H0001-HF with a taxonomy code such as 261QR0405X to identify a SUD-specialized provider.

• H0001 -HF — the intake assessment that begins every treatment episode: evaluating the presence and severity of substance use disorder through clinical measures and a biopsychosocial assessment at admission. The intake should resolve to a working F1x ICD-10 diagnosis and a signed treatment plan before subsequent sessions are billed — payers often audit the date of the first plan against the first billed counseling session.
• H0004 -HF — individual counseling, billed in 15-minute units (a 60-minute session is four units). Every unit should trace to a signed progress note citing the active diagnosis and the session’s measurable objective; payers deny units without that linkage during concurrent utilization review.
• 96164 -HF — in-person group health behavior intervention, billed per 30 minutes. An hour-long group is two units.

G-codes and Medicare

Medicare doesn’t pay for most H-codes — it has its own HCPCS G-code layer for behavioral health, which matters for facilities serving Medicare and dual-eligible patients:

For payer-specific Medicare billing mechanics, see the Medicare fee-for-service payer guide.

• SBIRT: G0396 and G0397 cover structured alcohol/substance misuse assessment and brief intervention (15–30 minutes and over 30 minutes respectively) for Medicare patients; commercial payers typically use 99408/ 99409 and Medicaid uses H0049/H0050.
• Annual screening: G0442 (annual alcohol misuse screening) and G0443 (brief face-to-face behavioral counseling for alcohol misuse) are Medicare preventive benefits with no patient cost-sharing.
• Opioid treatment program (OTP) bundles: G2067 – G2080 are weekly bundled payments for OTPs — G2067 covers a methadone week (drug plus dispensing, counseling, and toxicology within the bundle), G2068 covers oral buprenorphine, and the rest of the family covers other medications, non-drug bundles, intake ( G2076 ), periodic assessment ( G2077 ), and add-on counseling ( G2080 ). Medicare began paying OTPs through these bundles in 2020 under the SUPPORT Act; rates update annually in the Physician Fee Schedule final rule ↗.
• Virtual check-ins for SUD: G2086 – G2088 cover office-based opioid use disorder treatment bundles (first month, subsequent months, additional counseling).

Modifiers that change payment

Behavioral health claims lean on modifiers more than almost any other specialty — they identify the program type, the population served, the clinician’s credential, and the delivery method, and they routinely change the allowed amount. The most common:

Credential-level modifiers (AJ, HO, HN) often carry payer-specific payment differentials — Medicare, for example, pays clinical social worker claims at a percentage of the physician fee schedule amount. State Medicaid U-modifiers are the wild card: the same U1 means entirely different things in different states.

Deeper dives: the AJ modifier and HK modifier guides, the billing modifiers glossary entry, and the 2024 modifiers field guide.

Telehealth billing rules (95/93, POS 02/10)

Telehealth doesn’t use separate service codes — it uses the same psychotherapy, E/M, and assessment codes with telehealth indicators layered on:

POS selection affects payment: in-home telehealth is generally paid at the non-facility rate. Medicare made tele-behavioral health a permanent benefit category — including the patient’s home as an eligible originating site for mental health — though statutory in-person-visit requirements and their effective dates have shifted repeatedly with legislation. Commercial and Medicaid telehealth rules are payer-by-payer; treat every telehealth claim configuration (code + modifier + POS) as something to verify in the payer’s current policy, not something to carry over from last year. CMS guidance is published at cms.gov’s telehealth pages ↗.

• Modifier 95 for synchronous audio-video sessions.
• Modifier 93 for audio-only sessions, where the payer permits audio-only delivery (Medicare permits it for behavioral health under specified conditions).
• Place-of-service 02 — telehealth delivered somewhere other than the patient’s home.
• Place-of-service 10 — telehealth delivered in the patient’s home.

How facilities keep codes straight

A solo practice can keep its five codes on a sticky note. A facility billing detox, residential, PHP, IOP, and outpatient across a dozen payers cannot — the codeset itself updates quarterly (HCPCS) and annually (CPT), payer companion guides drift, and every level-of-care transition changes the billable code, the claim form, and the authorization requirements.

The operational pattern that works:

RCM platform scrubs claims pre-submission and your clearinghouse adds a second scrubbing pass before claims go out, catching invalid code/modifier combinations early; expanded payer-rule scrubbing on the side is on our roadmap. If your billing question is less about codes and more about whether to keep billing in-house, see the guide to mental health billing services.

• One source of truth for the charge master — codes, modifiers, units, and payer-specific variants maintained centrally, updated on the CMS quarterly HCPCS cycle and the annual CPT release each fall.
• Charge capture tied to clinical documentation — units should be generated from documented services (signed notes, attendance records), not keyed independently, so the claim and the chart can’t disagree.
• Claim scrubbing before submission — payer-specific edits that catch invalid code/modifier combinations, missing authorizations, and unit mismatches while they’re still cheap to fix. See the clearinghouse glossary guide for where scrubbing happens in the claim pipeline.

Which claim form do these codes go on?

The code family often determines the claim format — another distinction private-practice references never need to make:

Facilities running multiple levels of care routinely bill both formats in the same week for the same patient — one more reason facility billing is a different discipline from practice billing (the full comparison is in our guide to mental health billing services ). Claim-format specifications are published in CMS’s electronic billing and EDI transaction guidance ↗.

One related trap: when a payer contract covers the same clinical service under both a CPT code and an H-code (individual counseling as 90834 versus H0004 units, for example), the contract — not the clinical content — dictates which one pays. Billing the “wrong” right code is one of the most common silent underpayment patterns in behavioral health: the claim pays, just under the wrong fee schedule, and nothing flags it unless someone audits payment-to-contract.

Code usage descriptions on this page are original explanations of how these services are billed in behavioral health settings; they are not reproductions of official CPT descriptor text. CPT® is a registered trademark of the American Medical Association. This reference is informational and not billing, legal, or clinical advice — verify codes and rules against current payer and CMS guidance.

• CMS-1500 / 837P (professional claims) — psychotherapy CPT, diagnostic evaluations, testing codes, E/M visits, and most office-based H-code services billed by individual or supervising clinicians.
• UB-04 / 837I (institutional claims) — facility per-diems and program-level services: detox days, residential per-diems, and many PHP/IOP contracts. Institutional claims add revenue codes and bill types on top of the HCPCS code itself, and many payers require the same IOP service on different claim forms depending on the contract.

Reference tables

Common questions

Official sources

• HCPCS Level II quarterly update filescms.gov
• Medicare Claims Processing Manual (IOM Pub. 100-04)cms.gov
• Physician Fee Schedule final rulecms.gov
• cms.gov’s telehealth pagescms.gov
• electronic billing and EDI transaction guidancecms.gov