ICD-10 F16 Hallucinogen Codes: LSD, PCP,

The F16 category — hallucinogen related disorders — covers LSD, psilocybin, mescaline, MDMA/ecstasy, and (in a divergence from DSM-5-TR that trips up many coders) PCP and related dissociatives. It is a lower-volume family at most SUD facilities, but it contains one genuinely high-intent long-tail — hallucinogen persisting perception disorder (HPPD), the “flashbacks” code — and one accuracy trap competitors routinely fudge: F16 has no withdrawal codes at all.

Every code below is verified against the FY2026 ICD-10-CM tabular list ( CMS ICD-10-CM files ↗ ), effective October 1, 2025. Part of the ICD-10 behavioral health directory.

F16 at a glance

The FY2026 tabular lists three inclusion terms directly under the F16 category heading: ecstasy, PCP, and phencyclidine. In practice the family covers:

• Classic serotonergic hallucinogens — LSD, psilocybin, mescaline, DMT
• MDMA/ecstasy — listed by name in the tabular under F16 (not under the F15 stimulant family, despite MDMA’s stimulant pharmacology)
• Phencyclidine (PCP) and related dissociatives — see the boundary note below

The PCP boundary: where DSM-5-TR and ICD-10-CM diverge

DSM-5-TR maintains separate diagnostic categories for phencyclidine use disorder and “other hallucinogen” use disorder (paraphrased — the manual treats PCP as its own substance class). ICD-10-CM does not make that split: both classes share the F16 codes. The FY2026 Alphabetic Index confirms it — “PCP (phencyclidine) (or related substance)” routes to “Abuse, drug, hallucinogen” and “Dependence, drug, hallucinogen,” and the index entry “Phencyclidine-induced anxiety disorder” points to F16.980.

The practical consequence: a DSM-5-TR diagnosis of phencyclidine use disorder, moderate, and a diagnosis of LSD use disorder, moderate, both land on F16.20. Clinical documentation should always name the actual substance even though the code cannot distinguish them.

The three stems

Complete F16 code table (FY2026)

F16.1- — Hallucinogen abuse

F16.2- — Hallucinogen dependence

F16.9- — Hallucinogen use, unspecified

All 40 codes above are billable in the FY2026 code set.

No withdrawal codes — by design

Scan the table and you’ll notice what’s missing: there are no F16.x3 withdrawal codes. This is not an omission. The FY2026 tabular simply contains no withdrawal entries for hallucinogens, and DSM-5-TR likewise recognizes no hallucinogen withdrawal syndrome (paraphrased). Several F16 subcategories also lack the “perceptual disturbance” intoxication codes that F15 has at the dependence and unspecified stems — F16.222 and F16.922 do not exist in FY2026.

If a chart documents “hallucinogen withdrawal,” do not force a code from another family — query the provider. Often the documented substance turns out to be MDMA used alongside other drugs, cannabis (which does have withdrawal codes — F12.x3 family ), or an unknown substance better captured under F19.

Patient uses multiple substances? Each documented substance gets its own code — there is no polysubstance shortcut. See the F19 guide for the full rule.

HPPD: hallucinogen persisting perception disorder (flashbacks)

HPPD is the F16 family’s distinctive diagnosis: re-experiencing of perceptual disturbances (visual trails, halos, geometric patterns, flashback episodes) that persist or recur long after acute intoxication has resolved. The official ICD-10-CM descriptors carry “(flashbacks)” in the code title itself — F16.183, F16.283, and F16.983, selected by the severity of the underlying use disorder.

Documentation supporting an HPPD code should establish:

HPPD frequently presents at intake for a different primary problem — anxiety, cannabis use, alcohol use — and is coded secondary. The F16.983 form (use, unspecified) is the most commonly applicable when the patient’s historical hallucinogen use doesn’t meet current use-disorder criteria.

• The perceptual symptoms themselves — what the patient re-experiences, frequency, duration
• Temporal link to prior hallucinogen use — symptoms followed hallucinogen exposure and recur after sobriety
• Reality testing is intact — the patient recognizes the perceptions as drug-related (this distinguishes HPPD from a psychotic disorder; if reality testing is lost, the induced-psychosis codes F16.x5x or a primary psychosis diagnosis are on the table instead)
• Distress or impairment — clinically significant impact, not incidental visual phenomena

Hierarchy and remission rules

The ICD-10-CM Official Guidelines, Section I.C.5.b.2 ( FY2026 guidelines ↗ ), assign one code when documentation mentions multiple severity levels for the same substance:

Remission (Section I.C.5.b.3) requires explicit provider documentation: mild hallucinogen use disorder in early or sustained remission → F16.11; moderate or severe → F16.21 (paraphrased from the guideline mapping). F16.91 covers remission documented without severity.

The psychedelic-assisted-therapy era: what codes where

Two clarifications matter as ketamine clinics and psychedelic clinical trials reshape the referral landscape:

Ketamine. Ketamine does not appear by name in the FY2026 ICD-10-CM Alphabetic Index. DSM-5-TR groups ketamine with phencyclidine and other dissociatives in the hallucinogen class (paraphrased), which maps to F16 codes — the index’s “PCP (phencyclidine) (or related substance) ” entry is the route most coders use for ketamine-related use disorders.

Supervised therapeutic exposure is not a use disorder. A patient receiving ketamine-assisted or trial-protocol psychedelic treatment under clinical supervision is not thereby diagnosable with an F16 disorder — use-disorder criteria concern compulsive, harmful patterns, not administered doses. Code the condition being treated (depression, PTSD), and reserve F16 for documented problematic use. Facilities running both SUD programs and interventional psychiatry services should keep these chart populations cleanly separated for exactly this reason.

Documentation and billing

F16 codes are rarely the principal diagnosis at SUD facilities — hallucinogen use disorder seldom drives an admission by itself. The common billing patterns:

Medical-necessity narratives for any F16-anchored claim should connect symptoms to functional impairment — perceptual disturbance affecting driving, work, or safety lands far better with reviewers than the code alone.

• Secondary diagnosis coding. F16 codes most often ride alongside a principal F10–F15 diagnosis. List every substance the provider documents at use-disorder level; payers reviewing residential claims ( H0017 – H0019 ) and PHP/IOP claims ( H0035, H0015 ) expect the full diagnostic picture.
• Induced-psychosis admissions. Acute hallucinogen-induced psychosis (F16.x5x) can anchor a crisis-level or inpatient psychiatric claim. As with stimulant-induced psychosis, the note must document the psychotic features matching the 6th character (delusions vs. hallucinations) and the temporal link to use.
• Assessment and psychotherapy. Initial evaluation bills under 90791; individual psychotherapy under 90834 or related codes. HPPD work in outpatient settings typically pairs F16.983 with standard psychotherapy CPT codes.

Treatment planning

There is no medication approved for hallucinogen use disorder; treatment plans center on psychotherapy, psychoeducation, and management of co-occurring conditions. For HPPD specifically, plans typically include symptom tracking (frequency/intensity of perceptual episodes), trigger management (stress, cannabis, stimulants are commonly documented aggravators), and reassurance-based psychoeducation — with measurable objectives tied to episode frequency. Build diagnosis-anchored SMART goals using our treatment plan templates guide.

FAQ

What is the ICD-10 code for hallucinogen use disorder? F16.10 (mild/abuse), F16.20 (moderate-severe/dependence), or F16.90 (severity unspecified), uncomplicated forms.

Is there a hallucinogen withdrawal code? No. F16 contains no withdrawal codes in the FY2026 code set, consistent with DSM-5-TR’s position that there is no recognized hallucinogen withdrawal syndrome.

What is the HPPD code? F16.983 (use, unspecified, with hallucinogen persisting perception disorder) is the most commonly used; F16.183 and F16.283 apply when an abuse- or dependence-level disorder is documented.

What is the ICD-10 code for LSD abuse? F16.10 — LSD, psilocybin, mescaline, and other classic hallucinogens all share the F16 family.

Where does PCP code? F16. ICD-10-CM places phencyclidine with hallucinogens even though DSM-5-TR classifies it separately.

Where does MDMA/ecstasy code? F16 — “ecstasy” is a named inclusion term under the F16 category in the FY2026 tabular, despite MDMA’s stimulant-like pharmacology.

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• CMS, FY2026 ICD-10-CM Code Descriptions and Tabular List (effective Oct 1, 2025) — cms.gov/medicare/coding-billing/icd-10-codes ↗ (accessed 2026-06-12)
• CMS, FY2026 ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.5.b — fy-2026-icd-10-cm-coding-guidelines.pdf ↗ (accessed 2026-06-12)
• CDC/NCHS, ICD-10-CM — cdc.gov/nchs/icd/icd-10-cm ↗ (accessed 2026-06-12)

Reference tables

Common questions

Official sources

• CMS ICD-10-CM filescms.gov
• FY2026 guidelinescms.gov
• cdc.gov/nchs/icd/icd-10-cmcdc.gov