2026 ICD-10-CM Diagnosis Code T40.5X4SPoisoning by cocaine, undetermined, sequela
T40.5X4S is a billable ICD-10-CM diagnosis code for poisoning by cocaine, undetermined, 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. Coders also document this condition as poisoning by cocaine. 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
Code Classification
Present on Admission (POA)Billing
T40.5X4S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Poisoning by cocaine
- Poisoning by crack cocaine
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.
Clinical InformationClinical
Cocaine
an alkaloid ester extracted from the leaves of plants including coca. it is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. it also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake.Cocaine- and Amphetamine-Regulated Transcript Protein
neuropeptide that functions with neuropeptide y and leptin in the regulation of appetite. it also plays a role in neural development and is involved in the regulation of energy homeostasis and stress control.Cocaine Smoking
smoking of cocaine.Cocaine-Related Disorders
disorders related or resulting from use of cocaine.Crack Cocaine
the purified, alkaloidal, extra-potent form of cocaine. it is smoked (free-based), injected intravenously, and orally ingested. use of crack results in alterations in function of the cardiovascular system, the autonomic nervous system, the central nervous system, and the gastrointestinal system. the slang term crack was derived from the crackling sound made upon igniting of this form of cocaine for smoking.
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.
Patient EducationClinical
Cocaine
Cocaine is a very addictive drug that is made from leaves of the coca plant found in South America. It is mostly available as an illegal drug that some people use to get high. In rare cases, it is also used as a prescription drug for for anesthesia during certain surgeries.
The full article covers:
- What is cocaine?
- How do people use cocaine?
- What are the short-term effects of cocaine?
- What are the long-term effects of cocaine?
- Can a person overdose on cocaine?
- What are the treatments for cocaine use disorder?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T40.5X4S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T40.5X4SOverview
Is T40.5X4S (Poisoning by cocaine, undetermined) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by cocaine, undetermined, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T40.5X4S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by cocaine, undetermined itself has resolved, not the original event.
What MS-DRG does T40.5X4S group to?
When poisoning by cocaine, undetermined, 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 T40.5X4S 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 cocaine, undetermined, sequela on inpatient claims.
What is the ICD-9 equivalent of T40.5X4S?
Under the General Equivalence Mappings, poisoning by cocaine, undetermined, sequela converts to ICD-9-CM 909.0 (late eff drug poisoning) and E989 (late eff inj-undet circ). 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.
