2026 ICD-10-CM Diagnosis Code T52.4X1AToxic effect of ketones, accidental (unintentional), initial encounter

ICD-10-CM CodesS00–T88T51-T65T52

ICD-10-CM T52.4X1A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T52.4X1A is a billable ICD-10-CM diagnosis code for toxic effect of ketones, accidental (unintentional), initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 917 through 918. Coders also document this condition as toxic effect of acetone. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, accidental/unintentional; External cause codes: poisoning by non-drug; and Toxic effects, initial encounter.

Code Identity

ICD-10-CM Code
T52.4X1A
Billable Status
Yes — Valid for Submission
Code Describes
Toxic effect of ketones, accidental (unintentional), initial encounter
Short Description
Toxic effect of ketones, accidental (unintentional), init
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 CodeT52.4X1AToxic effect of ketones, accidental (unintentional), initial encounter

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 EXT020
External cause codes: intent of injury, accidental/unintentional
Default principal diagnosis: inpatient No · outpatient No
CCSR EXT015
External cause codes: poisoning by non-drug
Default principal diagnosis: inpatient No · outpatient No
CCSR INJ023
Toxic effects, initial encounter
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 T52.4X1A to ICD-9-CMHistory

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

ICD-9-CM
982.8 Toxic eff nonpetrol solv
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
E862.4 Acc poisn-solvents NEC
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 T52.4X1AOverview

Is T52.4X1A (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), initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T52.4X1A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for toxic effect of ketones, accidental (unintentional), such as an emergency visit or first evaluation.

What MS-DRG does T52.4X1A group to?

When toxic effect of ketones, accidental (unintentional), initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 917, 918, with relative weights from 0.8571 to 1.5684 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of T52.4X1A?

Under the General Equivalence Mappings, toxic effect of ketones, accidental (unintentional), initial encounter converts to ICD-9-CM 982.8 (toxic eff nonpetrol solv) and E862.4 (acc poisn-solvents NEC). 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.