2026 ICD-10-CM Diagnosis Code T40.903SPoisoning by unspecified psychodysleptics [hallucinogens], assault, sequela

ICD-10-CM Codes›S00–T88›T36-T50›T40

ICD-10-CM T40.903S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T40.903S is a billable ICD-10-CM diagnosis code for poisoning by unspecified psychodysleptics [hallucinogens], assault, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Mental and substance use disorders; sequela; and Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T40.903S
Billable Status
Yes — Valid for Submission
Code Describes
Poisoning by unspecified psychodysleptics [hallucinogens], assault, sequela
Short Description
Poisoning by unspecified psychodysleptics, assault, sequela
Parent Code
T40.903
Poisoning by unspecified psychodysleptics [hallucinogens], assault

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT36-T50Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
CategoryT40Poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens]
This CodeT40.903SPoisoning by unspecified psychodysleptics [hallucinogens], assault, sequela

Present on Admission (POA)Billing

T40.903S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Coding GuidelinesGuidance

When coding a poisoning or reaction to the improper use of a medication (e.g., overdose, wrong substance given or taken in error, wrong route of administration), first assign the appropriate code from categories T36-T50. The poisoning codes have an associated intent as their 5th or 6th character (accidental, intentional self-harm, assault and undetermined). If the intent of the poisoning is unknown or unspecified, code the intent as accidental intent. The undetermined intent is only for use if the documentation in the record specifies that the intent cannot be determined. Use additional code(s) for all manifestations of poisonings.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens] (T40). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MBD034
Mental and substance use disorders; sequela
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INJ075
Poisoning/toxic effect/adverse effects/underdosing, sequela
Default principal diagnosis: inpatient No · outpatient No

Table of Drugs and ChemicalsClinical

Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.

SubstanceAccidentalSelf-harmAssaultUndeter­minedAdverse
Effect		Under­dosing
Hallucinogen NOST40.901T40.902T40.903T40.904T40.905T40.906
Hallucinogen NOS::specified NECT40.901T40.902T40.903T40.904T40.905T40.906
MegahallucinogenT40.901T40.902T40.903T40.904T40.905T40.906
Psychodysleptic drug NOST40.901T40.902T40.903T40.904T40.905T40.906
Psychodysleptic drug NOS::specified NECT40.901T40.902T40.903T40.904T40.905T40.906
Psychotomimetic agentsT40.901T40.902T40.903T40.904T40.905T40.906

Patient EducationClinical

Poisoning

A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be poisonous if too much is taken. Poisons can include:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T40.903S to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
909.0 Late eff drug poisoning
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
E969 Late effect assault
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T40.903SOverview

Is T40.903S a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by unspecified psychodysleptics [hallucinogens], assault, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T40.903S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by unspecified psychodysleptics [hallucinogens], assault itself has resolved, not the original event.

What MS-DRG does T40.903S group to?

When poisoning by unspecified psychodysleptics [hallucinogens], assault, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T40.903S exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for poisoning by unspecified psychodysleptics [hallucinogens], assault, sequela on inpatient claims.

What is the ICD-9 equivalent of T40.903S?

Under the General Equivalence Mappings, poisoning by unspecified psychodysleptics [hallucinogens], assault, sequela converts to ICD-9-CM 909.0 (late eff drug poisoning) and E969 (late effect assault). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.