2026 ICD-10-CM Diagnosis Code T39.1X1SPoisoning by 4-Aminophenol derivatives, accidental (unintentional), sequela

ICD-10-CM Codes›S00–T88›T36-T50›T39

ICD-10-CM T39.1X1S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T39.1X1S is a billable ICD-10-CM diagnosis code for poisoning by 4-Aminophenol derivatives, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T39.1X1S
Billable Status
Yes — Valid for Submission
Code Describes
Poisoning by 4-Aminophenol derivatives, accidental (unintentional), sequela
Short Description
Poisoning by 4-Aminophenol derivatives, accidental, sequela
Parent Code
T39.1X1
Poisoning by 4-Aminophenol derivatives, accidental (unintentional)

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
CategoryT39Poisoning by, adverse effect of and underdosing of nonopioid analgesics, antipyretics and antirheumatics
This CodeT39.1X1SPoisoning by 4-Aminophenol derivatives, accidental (unintentional), sequela

Present on Admission (POA)Billing

T39.1X1S 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.

  • Accidental acetaminophen and/or dextropropoxyphene overdose
  • Accidental acetaminophen and/or dextropropoxyphene poisoning
  • Accidental acetaminophen overdose
  • Accidental acetaminophen poisoning
  • Accidental poisoning by acetanilide
  • Accidental poisoning by phenacetin
  • Acetaminophen and/or dextropropoxyphene overdose
  • Acetaminophen and/or dextropropoxyphene poisoning
  • Acetaminophen overdose
  • Acetanilide poisoning
  • Phenacetin poisoning
  • Poisoning caused by acetaminophen

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 nonopioid analgesics, antipyretics and antirheumatics (T39). 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

Clinical InformationClinical

  • Acetaminophen

    analgesic antipyretic derivative of acetanilide. it has weak anti-inflammatory properties and is used as a common analgesic, but may cause liver, blood cell, and kidney damage.

  • Arylsulfotransferase

    a sulfotransferase that catalyzes the sulfation of a phenol in the presence of 3'-phosphoadenylylsulfate as sulfate donor to yield an aryl sulfate and adenosine 3',5'-bisphosphate. a number of aromatic compounds can act as acceptors; however, organic hydroxylamines are not substrates. sulfate conjugation by this enzyme is a major pathway for the biotransformation of phenolic and catechol drugs as well as neurotransmitters. ec 2.8.2.1.

  • Cytochrome P-450 CYP1A2

    a cytochrome p450 enzyme subtype that has specificity for relatively planar heteroaromatic small molecules, such as caffeine and acetaminophen.

  • Phenacetin

    a phenylacetamide that was formerly used in analgesics but nephropathy and methemoglobinemia led to its withdrawal from the market. (from smith and reynard, textbook of pharmacology,1991, p431)

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
P-AcetamidophenolT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
AcetaminophenT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
AcetaminosalolT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
AcetanilideT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
AcetophenetedinT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
4-Aminophenol derivativesT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
Bromo-seltzerT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
ExalginT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
PanadolT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
Para-acetamidophenolT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
Para-aminophenol derivativesT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
ParacetamolT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6
PhenacetinT39.1X1T39.1X2T39.1X3T39.1X4T39.1X5T39.1X6

Patient EducationClinical

Medication Errors

Medicines treat infectious diseases, prevent problems from chronic diseases, and ease pain. But medicines can also cause harmful reactions if not used correctly. Errors can happen in the hospital, at the health care provider's office, at the pharmacy, or at home. You can help prevent errors by:

Read the full article at MedlinePlus

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

Convert T39.1X1S 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
E929.2 Late eff acc poisoning
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 T39.1X1SOverview

Is T39.1X1S a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by 4-Aminophenol derivatives, accidental (unintentional), sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T39.1X1S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by 4-Aminophenol derivatives, accidental (unintentional) itself has resolved, not the original event.

What MS-DRG does T39.1X1S group to?

When poisoning by 4-Aminophenol derivatives, 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 T39.1X1S 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 4-Aminophenol derivatives, accidental (unintentional), sequela on inpatient claims.

What is the ICD-9 equivalent of T39.1X1S?

Under the General Equivalence Mappings, poisoning by 4-Aminophenol derivatives, accidental (unintentional), sequela converts to ICD-9-CM 909.0 (late eff drug poisoning) and E929.2 (late eff acc poisoning). 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.