2026 ICD-10-CM Diagnosis Code T44.0X1SPoisoning by anticholinesterase agents, accidental (unintentional), sequela
T44.0X1S is a billable ICD-10-CM diagnosis code for poisoning by anticholinesterase agents, 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 accidental anticholinesterase overdose. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
T44.0X1S 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 anticholinesterase overdose
- Accidental poisoning by anticholinesterase
- Accidental poisoning by cholinergic
- Anticholinesterase overdose
- Poisoning by anticholinesterase
- Poisoning by organophosphorus anticholinesterase
- Poisoning by reversible anticholinesterase
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 drugs primarily affecting the autonomic nervous system (T44). 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
Edrophonium
a rapid-onset, short-acting cholinesterase inhibitor used in cardiac arrhythmias and in the diagnosis of myasthenia gravis. it has also been used as an antidote to curare principles.Galantamine
a benzazepine derived from norbelladine. it is found in galanthus and other amaryllidaceae. it is a cholinesterase inhibitor that has been used to reverse the muscular effects of gallamine triethiodide and tubocurarine and has been studied as a treatment for alzheimer disease and other central nervous system disorders.Isoflurophate
a di-isopropyl-fluorophosphate which is an irreversible cholinesterase inhibitor used to investigate the nervous system.Pyridostigmine Bromide
a cholinesterase inhibitor with a slightly longer duration of action than neostigmine. it is used in the treatment of myasthenia gravis and to reverse the actions of muscle relaxants.Tacrine
a cholinesterase inhibitor that crosses the blood-brain barrier. tacrine has been used to counter the effects of muscle relaxants, as a respiratory stimulant, and in the treatment of alzheimer's disease and other central nervous system disorders.
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
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 T44.0X1S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T44.0X1SOverview
Is T44.0X1S a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by anticholinesterase agents, accidental (unintentional), sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T44.0X1S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by anticholinesterase agents, accidental (unintentional) itself has resolved, not the original event.
What MS-DRG does T44.0X1S group to?
When poisoning by anticholinesterase agents, 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 T44.0X1S 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 anticholinesterase agents, accidental (unintentional), sequela on inpatient claims.
What is the ICD-9 equivalent of T44.0X1S?
Under the General Equivalence Mappings, poisoning by anticholinesterase agents, 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.
