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F16.90 ICD-10-CM Code: Hallucinogen use, unspecified, uncomplicated

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
3 inclusion terms · 2 Excludes1

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 894 — ALCOHOL, DRUG ABUSE OR DEPENDENCE, LEFT AMA (MDC 20)
  • MS-DRG 895 — ALCOHOL, DRUG ABUSE OR DEPENDENCE WITH REHABILITATION THERAPY (MDC 20)
  • MS-DRG 896 — ALCOHOL, DRUG ABUSE OR DEPENDENCE WITHOUT REHABILITATION THERAPY WITH MCC (MDC 20)
  • MS-DRG 897 — ALCOHOL, DRUG ABUSE OR DEPENDENCE WITHOUT REHABILITATION THERAPY WITHOUT MCC (MDC 20)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for F16.90 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on F16.90 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • ecstasy
  • PCP
  • phencyclidine

Source: inherited from F16

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from F16.9

Coder workflow for F16.90

MedCoder structured workflow — derived from this code’s own official record

Before you code F16.90

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, F16.90 may be the appropriate code. Check the record for detail that supports a more specific sibling — in this subcategory the siblings differ by the presence or absence of the associated condition. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  2. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with F16.90. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — F16.90 is appropriate when the documentation goes no further.
  2. Does the documentation support a condition named in F16.90’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewF16.1, F16.2

Consider F16.90. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes1 — check before selecting F16.90(2 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with F16.90: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareF16.1, F16.2

    See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the subcategory for a sibling that names the missing detail.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

Documentation: Both the condition F16.90 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewF16.1, F16.2

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Hallucinogen use, unspecified, uncomplicated is a billable ICD-10-CM diagnosis code (F16.90).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 5: Mental, Behavioral and Neurodevelopmental disorders (F01 – F99)

3) Psychoactive Substance Use, Unspecified As with all other unspecified diagnoses, the codes for unspecified psychoactive substance use (F10.9-, F11.9-, F12.9-, F13.9-, F14.9-, F15.9-, F16.9-, F18.9-, F19.9-) should only be assigned based on provider documentation and when they meet the definition of a reportable diagnosis (see Section III, Reporting Additional Diagnoses). These codes are to be used only when the psychoactive substance use is associated with a substance related disorder (chapter 5 disorders such as sexual dysfunction, sleep disorder, or a mental or behavioral disorder) or medical condition, and such a relationship is documented by the provider.

Chapter 15: Pregnancy, Childbirth, and the Puerperium (O00-O9A)

3) Drug use during pregnancy, childbirth and the puerperium Codes under subcategory O99.32, Drug use complicating pregnancy, childbirth, and the puerperium, should be assigned for any pregnancy case when a patient uses drugs during the pregnancy or postpartum. This can involve illegal drugs, or inappropriate use or abuse of prescription drugs. Secondary code(s) from categories F11-F16 and F18-F19 should also be assigned to identify manifestations of the drug use.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name F16.90 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 4 Excludes1 notes across 2 chapters: F16.1 — Hallucinogen abuse (via F16.9.-), F16.2 — Hallucinogen dependence (via F16.9.-), R41.3 — Other amnesia (via F16.-), R44 — Other symptoms and signs involving general sensations and perceptions (via F16.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 33 Excludes2 notes across 4 chapters: F02 — Dementia in other diseases classified elsewhere (via F16.-), F06 — Other mental disorders due to known physiological condition (via F16.-), F06.0 — Psychotic disorder with hallucinations due to known physiological condition (via F16.-), F06.2 — Psychotic disorder with delusions due to known physiological condition (via F16.-), F06.3 — Mood disorder due to known physiological condition (via F16.-), F06.4 — Anxiety disorder due to known physiological condition (via F16.-), F20 — Schizophrenia (via F16.-), F55 — Abuse of non-psychoactive substances (via F16.-), F63 — Impulse disorders (via F16.-), F63.1 — Pyromania (via F16.-), R78 — Findings of drugs and other substances, not normally found in blood (via F16.-), T36 — Poisoning by, adverse effect of and underdosing of systemic antibiotics (via F16.-), T36-T39 — Antibiotics & Anti-infectives (T36-T39) (via F16.-), T36-T50 — Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50) (via F16.-), T37 — Poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics (via F16.-), T38 — Poisoning by, adverse effect of and underdosing of hormones and their synthetic substitutes and antagonists, not elsewhere classified (via F16.-), T39 — Poisoning by, adverse effect of and underdosing of nonopioid analgesics, antipyretics and antirheumatics (via F16.-), T40 — Poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens] (via F16.-), T40-T41 — Analgesics & Antipyretics (T40-T41) (via F16.-), T41 — Poisoning by, adverse effect of and underdosing of anesthetics and therapeutic gases (via F16.-), +13 more.

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 2 Use Additional Code instructions across 2 chapters: O99.32 — Drug use complicating pregnancy, childbirth, and the puerperium (via F16.-), Z71.5 — Drug abuse counseling and surveillance (via F16.-).

These codes instruct coders to additionally report this code when it applies.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 4 MS-DRGs: DRG 894 (MDC 20), DRG 895 (MDC 20), DRG 896 (MDC 20), DRG 897 (MDC 20).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):MBD022 — Hallucinogen-related disorders (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Hallucinogen-related disorders).

F16.221 — Hallucinogen dependence with intoxication with delirium, F16.229 — Hallucinogen dependence with intoxication, unspecified, F16.24 — Hallucinogen dependence with hallucinogen-induced mood disorder, F16.250 — Hallucinogen dependence with hallucinogen-induced psychotic disorder with delusions, F16.251 — Hallucinogen dependence with hallucinogen-induced psychotic disorder with hallucinations, F16.259 — Hallucinogen dependence with hallucinogen-induced psychotic disorder, unspecified, F16.280 — Hallucinogen dependence with hallucinogen-induced anxiety disorder, F16.283 — Hallucinogen dependence with hallucinogen persisting perception disorder (flashbacks), F16.288 — Hallucinogen dependence with other hallucinogen-induced disorder, F16.29 — Hallucinogen dependence with unspecified hallucinogen-induced disorder, F16.920 — Hallucinogen use, unspecified with intoxication, uncomplicated, F16.921 — Hallucinogen use, unspecified with intoxication with delirium, F16.929 — Hallucinogen use, unspecified with intoxication, unspecified, F16.94 — Hallucinogen use, unspecified with hallucinogen-induced mood disorder, F16.950 — Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder with delusions, F16.951 — Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder with hallucinations, F16.959 — Hallucinogen use, unspecified with hallucinogen-induced psychotic disorder, unspecified, F16.980 — Hallucinogen use, unspecified with hallucinogen-induced anxiety disorder, F16.983 — Hallucinogen use, unspecified with hallucinogen persisting perception disorder (flashbacks), F16.988 — Hallucinogen use, unspecified with other hallucinogen-induced disorder, +34 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Use”; these codes share that main term but sit in a different category of the Tabular List.

F15.93 — Other stimulant use, unspecified with withdrawal (stimulant NEC, with, withdrawal), F15.94 — Other stimulant use, unspecified with stimulant-induced mood disorder (stimulant NEC, with, mood disorder), F15.950 — Other stimulant use, unspecified with stimulant-induced psychotic disorder with delusions (stimulant NEC, with, psychosis, delusions), F15.951 — Other stimulant use, unspecified with stimulant-induced psychotic disorder with hallucinations (stimulant NEC, with, psychosis, hallucinations), F15.959 — Other stimulant use, unspecified with stimulant-induced psychotic disorder, unspecified (stimulant NEC, with, psychosis), F15.980 — Other stimulant use, unspecified with stimulant-induced anxiety disorder (stimulant NEC, with, anxiety disorder), F15.981 — Other stimulant use, unspecified with stimulant-induced sexual dysfunction (stimulant NEC, with, sexual dysfunction), F15.982 — Other stimulant use, unspecified with stimulant-induced sleep disorder (stimulant NEC, with, sleep disorder), F15.988 — Other stimulant use, unspecified with other stimulant-induced disorder (stimulant NEC, with, other specified disorder), F15.99 — Other stimulant use, unspecified with unspecified stimulant-induced disorder (stimulant NEC, with, unspecified disorder), F18.90 — Inhalant use, unspecified, uncomplicated (inhalants), F18.91 — Inhalant use, unspecified, in remission (inhalants, in remission), F18.920 — Inhalant use, unspecified with intoxication, uncomplicated (inhalants, with, intoxication, uncomplicated), F18.921 — Inhalant use, unspecified with intoxication with delirium (inhalants, with, intoxication, with delirium), F18.929 — Inhalant use, unspecified with intoxication, unspecified (inhalants, with, intoxication), F18.94 — Inhalant use, unspecified with inhalant-induced mood disorder (inhalants, with, mood disorder), F18.950 — Inhalant use, unspecified with inhalant-induced psychotic disorder with delusions (inhalants, with, psychosis, delusions), F18.951 — Inhalant use, unspecified with inhalant-induced psychotic disorder with hallucinations (inhalants, with, psychosis, hallucinations), F18.959 — Inhalant use, unspecified with inhalant-induced psychotic disorder, unspecified (inhalants, with, psychosis), F18.97 — Inhalant use, unspecified with inhalant-induced persisting dementia (inhalants, with, persisting dementia), +95 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Gamma-glutamyl Transferase (GGT) Test

Contextual Map

Every relationship of F16.90 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run F16.90 with these 14 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Referenced by Excludes2 notes (33)

Referenced by Use Additional Code instructions

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 20 — Alcohol or Drug Use or Induced Organic Mental Disorders[MDC crossing]: “Alcohol or Drug Use or Induced Organic Mental Disorders — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 35 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • LSD reaction (acute) (without dependence)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Use (of), hallucinogen NEC[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (40)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "F16.90 — Hallucinogen use, unspecified, uncomplicated." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/f16.90-hallucinogen-use-unspecified-uncomplicated

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Hallucinogen use, unspecified, uncomplicated

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to F16.90 in its code family, with their registry titles.

View all codes in the F16 family