ICD-10 F19 Codes & the Polysubstance Coding

F19 — other psychoactive substance related disorders — is simultaneously the most misused category in substance use disorder coding and the only correct home for a growing list of substances: kratom, novel psychoactives, and anything a patient took that nobody can identify yet. The misuse comes from one persistent habit: treating F19 as a “polysubstance” shortcut when a patient uses several drugs. ICD-10-CM retired DSM-IV-era polysubstance dependence as a diagnosis, and coding F19.20 instead of listing each substance undercodes the chart, weakens the claim, and misstates the clinical picture.

This guide covers what actually belongs in F19, the full FY2026 code table — F19 is the largest table in the F10–F19 block, with withdrawal codes and both persisting amnestic disorder and dementia — and the correction-intent answer most searchers came for: how to code the patient who uses everything.

All codes verified against the FY2026 ICD-10-CM tabular list and Alphabetic Index ( CMS ICD-10-CM files ↗ ), effective October 1, 2025. Part of the ICD-10 behavioral health directory.

F19 at a glance

The FY2026 tabular lists one inclusion term under the F19 category heading: polysubstance drug use (indiscriminate drug use) — more on that loaded phrase below. The category functions as the catch-all for psychoactive substances with no dedicated F10–F18 home:

Two important boundary corrections, both verified against the FY2026 Alphabetic Index:

• Kratom — no FY2026 index entry by name; conventionally reported under F19
• Novel psychoactive substances (“research chemicals,” new synthetics not yet classified elsewhere)
• Nitrite inhalants and nitrous oxide — DSM-5-TR places nitrites outside the inhalant class (paraphrased), pointing coding toward F19 rather than F18
• Unknown substances — the patient is intoxicated or withdrawing and the substance has not been identified
• Truly indiscriminate use — the narrow case where the inclusion term applies

• Synthetic cannabinoids (K2/Spice) are NOT F19. The index routes “cannabis, cannabinoids” to the cannabis entries — F12.
• PCP and ketamine-type dissociatives are NOT F19. The index routes “PCP (phencyclidine) (or related substance)” to the hallucinogen entries — F16.

The three stems

The polysubstance problem: code each substance, not F19

Here is the precise, two-part truth — most pages on this topic tell only half of it:

Part 1: There is no polysubstance diagnosis in ICD-10-CM. “Polysubstance dependence” was a DSM-IV and ICD-9 concept; DSM-5 eliminated it, and ICD-10-CM never had a dedicated category. When a provider documents use disorders involving multiple named substances, each one gets its own code: alcohol dependence → F10.20, opioid dependence → F11.20, cocaine dependence → F14.20 — all three on the claim, sequenced by the reason for the encounter.

Part 2: The index still maps the bare word “polysubstance” to F19.20. The FY2026 Alphabetic Index carries the entry “Dependence, drug, polysubstance — F19.20,” and the tabular’s inclusion term “polysubstance drug use (indiscriminate drug use)” sits at the F19 category level. So a chart that says only “polysubstance dependence” — with no substances named anywhere — does technically index to F19.20. That entry exists for genuinely indiscriminate use (“patient takes whatever is available”); it is not permission to compress a documented alcohol-opioid-cocaine picture into one code.

Decision flow

• Are individual substances documented anywhere in the record? → Code each at its documented severity (F10–F18 families). Do not add F19.
• Does the provider document truly indiscriminate use — substances vary, no primary substance identifiable? → F19.- per the inclusion term, ideally with a provider note saying exactly that.
• Does the chart say only “polysubstance abuse/dependence” but the H&P, tox screen, or assessment names the substances? → Query the provider. The named substances should be coded individually.

Why it matters on the claim

Collapsing multiple use disorders into F19.20 has three concrete costs:

• Medical necessity weakens. A residential claim supported by alcohol dependence with withdrawal plus opioid dependence plus stimulant-induced sleep disorder describes acuity across multiple ASAM dimensions. “F19.20” describes almost nothing, and utilization reviewers treat it accordingly.
• Payer scrutiny rises. F19.20-anchored residential claims are a known review trigger precisely because the code is so often a documentation shortcut.
• Severity reporting and risk adjustment lose data. Each uncoded substance is clinical complexity the record no longer reflects.

Complete F19 code table (FY2026)

F19 is the largest family in the block — 65 billable codes — because it carries everything: full withdrawal subcodes (like F10/F11/F13), plus both persisting amnestic disorder and persisting dementia.

F19.1- — Other psychoactive substance abuse

F19.2- — Other psychoactive substance dependence

F19.9- — Other psychoactive substance use, unspecified

Coding unknown and unconfirmed substances

The legitimate, everyday use of F19.9- is the patient who arrives intoxicated or withdrawing on something unidentified — ED transfers, street-drug exposures with unreliable history, pre-tox-screen admissions. The workflow:

Note that a positive tox screen alone does not establish a use disorder — the provider must document the diagnosis. Screening results without an associated diagnosis are coded with the appropriate findings codes rather than F-codes.

• At presentation, code what is documented: F19.920/F19.929 for unknown-substance intoxication, F19.930/F19.939 for unknown-substance withdrawal, based on the provider’s clinical findings.
• When the substance is identified — tox screen returns, history clarifies — subsequent encounters are coded to the specific family ( fentanyl → F11, methamphetamine → F15 ). The code follows the documentation available for each encounter; earlier encounters are not retroactively wrong.
• If results contradict the working code before claim submission, correct the diagnosis before the claim goes out — diagnosis-claim mismatches against later-documented results are easy audit findings.

Hierarchy and remission rules

The Official Guidelines, Section I.C.5.b.2 ( FY2026 guidelines ↗ ), apply per substance, including the “other” substance:

Remission (Section I.C.5.b.3) requires explicit provider documentation: mild → F19.11, moderate/severe → F19.21, severity undocumented → F19.91 (paraphrased from the guideline mapping).

Documentation and billing: multi-code claims done right

Facilities treating multi-substance patients live in multi-code claims, and the F19 misuse pattern usually starts as a billing shortcut. The defensible pattern:

• Principal diagnosis selection. Per the guidelines’ general rules (Section II for inpatient settings), sequence first the condition chiefly responsible for the admission — usually the substance driving the level-of-care decision (e.g., the alcohol dependence with withdrawal that necessitated medically-monitored detox), with every other documented use disorder as additional diagnoses.
• Each substance earns its own medical-necessity weight. Residential ( H0017, H0018, H0019 ), withdrawal management ( H0010 ), and PHP/IOP claims ( H0035, H0015 ) read stronger when the diagnosis list reflects true multi-substance acuity. Map findings to ASAM dimensions — see ASAM criteria and payer authorization.
• Audit your F19.20 rate. A simple RCM health check: what share of your SUD claims carry F19.20 as principal? Facilities with high rates almost always have a documentation-shortcut problem upstream, not a population of indiscriminate users. With you can export your diagnosis and claims data across the app to review patterns like this; our behavioral health RCM overview covers the wider revenue cycle.

Treatment planning

Multi-substance and unknown-substance cases need treatment plans that track each diagnosis separately — distinct problem statements, goals, and objectives per documented use disorder, updated as tox results clarify the picture. A plan whose problem list says “ polysubstance use ” inherits all the weaknesses of the F19.20 shortcut: nothing is measurable and nothing maps to a specific intervention. Structure diagnosis-anchored SMART goals with our treatment plan templates guide.

FAQ

What is the ICD-10 code for polysubstance abuse? There is no polysubstance category. Code each documented substance separately. Bare “polysubstance dependence” documentation indexes to F19.20, but query for specifics whenever the record names substances.

What is F19.20? Other psychoactive substance dependence, uncomplicated — for moderate/severe use disorders involving substances without a dedicated category, or undifferentiated “polysubstance dependence” documentation.

What is the kratom ICD-10 code? Kratom has no named index entry in FY2026; it is conventionally coded under F19 by documented severity (F19.10 / F19.20 / F19.90).

What about synthetic cannabinoids (K2/Spice)? Not F19 — the Alphabetic Index routes cannabinoids to the cannabis family, F12.

How do I code an unknown substance? F19.9- with the documented presentation: F19.929 intoxication, F19.939 withdrawal. Recode to the specific family once identified.

Does F19 have withdrawal codes? Yes — full withdrawal subcodes at every stem (F19.130-139, F19.230-239, F19.930-939), unlike F14, F16, and F18.

• CMS, FY2026 ICD-10-CM Code Descriptions, Tabular List, and Alphabetic Index (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, Sections I.C.5.b and II — 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