2026 ICD-10-CM Diagnosis Code T52.4X1SToxic effect of ketones, accidental (unintentional), sequela

ICD-10-CM CodesS00–T88T51-T65T52

ICD-10-CM T52.4X1S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T52.4X1S is a billable ICD-10-CM diagnosis code for toxic effect of ketones, accidental (unintentional), 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 toxic effect of acetone. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T52.4X1S
Billable Status
Yes — Valid for Submission
Code Describes
Toxic effect of ketones, accidental (unintentional), sequela
Short Description
Toxic effect of ketones, accidental (unintentional), sequela
Same as the full description in the CMS dataset.
Parent Code
Toxic effect of ketones, accidental (unintentional)

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT51-T65Toxic effects of substances chiefly nonmedicinal as to source
CategoryT52Toxic effect of organic solvents
This CodeT52.4X1SToxic effect of ketones, accidental (unintentional), sequela

Present on Admission (POA)Billing

T52.4X1S 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.

  • Toxic effect of acetone

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Toxic effect of organic solvents (T52). 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 INJ075
Poisoning/toxic effect/adverse effects/underdosing, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

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
Acetone (oils)T52.4X1T52.4X2T52.4X3T52.4X4
Acetone (oils)::chlorinatedT52.4X1T52.4X2T52.4X3T52.4X4
Acetone (oils)::vaporT52.4X1T52.4X2T52.4X3T52.4X4
AcetophenoneT52.4X1T52.4X2T52.4X3T52.4X4
Butanone, 2-butanoneT52.4X1T52.4X2T52.4X3T52.4X4
CyclohexanoneT52.4X1T52.4X2T52.4X3T52.4X4
Diacetone alcoholT52.4X1T52.4X2T52.4X3T52.4X4
Hexanone, 2-hexanoneT52.4X1T52.4X2T52.4X3T52.4X4
HexoneT52.4X1T52.4X2T52.4X3T52.4X4
HydroxymethylpentanoneT52.4X1T52.4X2T52.4X3T52.4X4
KetolsT52.4X1T52.4X2T52.4X3T52.4X4
Ketone oilsT52.4X1T52.4X2T52.4X3T52.4X4
MEK (methyl ethyl ketone)T52.4X1T52.4X2T52.4X3T52.4X4
MethylT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::acetateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::acetoneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::acrylateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::alcoholT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::aminophenolT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::amphetamineT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::androstanoloneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::atropineT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::benzeneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::benzoateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::benzolT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::bromide (gas)T52.4X1T52.4X2T52.4X3T52.4X4
Methyl::bromide (gas)::fumigantT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::butanolT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::carbinolT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::carbonateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::CCNUT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::cellosolveT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::celluloseT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::chloride (gas)T52.4X1T52.4X2T52.4X3T52.4X4
Methyl::chloroformateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::cyclohexaneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::cyclohexanolT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::cyclohexanoneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::cyclohexyl acetateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::demetonT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::dihydromorphinoneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::ergometrineT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::ergonovineT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::ethyl ketoneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::glucamine antimonateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::hydrazineT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::iodideT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::isobutyl ketoneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::isothiocyanateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::mercaptanT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::morphine NECT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::nicotinateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::parabenT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::parafynolT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::parathionT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::peridolT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::phenidateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::prednisoloneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::prednisolone::ENT agentT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::prednisolone::ophthalmic preparationT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::prednisolone::topical NECT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::propylcarbinolT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::rosaniline NECT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::salicylateT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::sulfate (fumes)T52.4X1T52.4X2T52.4X3T52.4X4
Methyl::sulfate (fumes)::liquidT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::sulfonalT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::testosteroneT52.4X1T52.4X2T52.4X3T52.4X4
Methyl::thiouracilT52.4X1T52.4X2T52.4X3T52.4X4

Convert T52.4X1S to ICD-9-CMHistory

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

ICD-9-CM
909.1 Late eff nonmed substanc
Approximate The match is approximate rather than exact.

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 T52.4X1SOverview

Is T52.4X1S (Toxic effect of ketones, accidental (unintentional)) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report toxic effect of ketones, accidental (unintentional), sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T52.4X1S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the toxic effect of ketones, accidental (unintentional) itself has resolved, not the original event.

What MS-DRG does T52.4X1S group to?

When toxic effect of ketones, accidental (unintentional), 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 T52.4X1S 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 toxic effect of ketones, accidental (unintentional), sequela on inpatient claims.

What is the ICD-9 equivalent of T52.4X1S?

Under the General Equivalence Mappings, toxic effect of ketones, accidental (unintentional), sequela converts to ICD-9-CM 909.1 (late eff nonmed substanc). 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.