2027 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 2027 (October 1, 2026 through September 30, 2027) 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 the other POA exempt codes in Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances (T36-T50).
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 2027, published by CMS and the National Center for Health Statistics.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to T40.5X4S: its own notes plus those printed at T40, block T36-T50, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- adverse effect of correct substance properly administered
- poisoning by overdose of substance
- poisoning by wrong substance given or taken in error
- underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- toxic reaction to local anesthesia in pregnancy (O29.3-)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Code First
The underlying condition named in the note is sequenced before this code.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify any retained foreign body, if applicable (Z18.-)
Notes
General instructions on how these codes are used.
- Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
- The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.
7th Character
Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.
- The appropriate 7th character is to be added to each code from category T40
- Ainitial encounter
- Dsubsequent encounter
- Ssequela this code
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name T40.5X4S, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming T40.5X4S: they are not reported together with it, unless the two conditions are unrelated.
- T41 Poisoning by, adverse effect of and underdosing of anesthetics and therapeutic gasescocaine (T40.5-) names T40.5-, which includes this code
- T43.6 Poisoning by, adverse effect of and underdosing of psychostimulantspoisoning by, adverse effect of and underdosing of cocaine (T40.5-) names T40.5-, which includes this code
Excludes2 2
These codes carry an Excludes2 note naming T40.5X4S: its condition is not part of those codes, and both may be reported when the patient has both.
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.
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
What is the ICD-10 code for poisoning by cocaine, undetermined, sequela?
The ICD-10-CM code for poisoning by cocaine, undetermined, sequela is T40.5X4S (sometimes written as T405X4S). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
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, 2026 through September 30, 2027.
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 923, 922, with relative weights from 0.9980 to 1.6248 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. The code appears in the Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances (T36-T50) range of the CMS exempt list.
