2026 ICD-10-CM Diagnosis Code T44.0X5SAdverse effect of anticholinesterase agents, sequela

ICD-10-CM CodesS00–T88T36-T50T44

ICD-10-CM T44.0X5S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T44.0X5S is a billable ICD-10-CM diagnosis code for adverse effect of anticholinesterase agents, 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 not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. Coders also document this condition as anticholinesterase parasympathomimetic adverse reaction. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T44.0X5S
Billable Status
Yes — Valid for Submission
Code Describes
Adverse effect of anticholinesterase agents, sequela
Short Description
Adverse effect of anticholinesterase agents, sequela
Same as the full description in the CMS dataset.
Parent Code
Adverse effect of anticholinesterase agents

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
CategoryT44Poisoning by, adverse effect of and underdosing of drugs primarily affecting the autonomic nervous system
This CodeT44.0X5SAdverse effect of anticholinesterase agents, sequela

Code EditsBilling

Medicare Code Editor checks that affect claim validity for T44.0X5S.

There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)Billing

T44.0X5S 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.

  • Anticholinesterase parasympathomimetic adverse reaction
  • Distigmine adverse reaction
  • Edrophonium adverse reaction
  • Neostigmine adverse reaction
  • Pyridostigmine adverse reaction

Coding GuidelinesGuidance

When coding an adverse effect of a drug that has been correctly prescribed and properly administered, assign the appropriate code for the nature of the adverse effect followed by the appropriate code for the adverse effect of the drug.

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.

CCSR INJ075
Poisoning/toxic effect/adverse effects/underdosing, sequela
Default principal diagnosis: inpatient No · outpatient Yes

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.

SubstanceAccidentalSelf-harmAssaultUndeter­minedAdverse
Effect
Under­dosing
Ambenonium (chloride)T44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
AnticholinesteraseT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
Anticholinesterase::organophosphorusT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
Anticholinesterase::organophosphorus::insecticideT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
Anticholinesterase::organophosphorus::nerve gasT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
Anticholinesterase::reversibleT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
Anticholinesterase::reversible::ophthalmologicalT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
DFPT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
DiflosT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
DifluorophateT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
DiisopropylfluorophosphateT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
Distigmine (bromide)T44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
DyflosT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
EdrophoniumT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
Edrophonium::chlorideT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
GalantamineT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
IsoflurophateT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
Neostigmine bromideT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
ProstigminT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
Pyridostigmine bromideT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
TacrineT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6
TetrahydroaminoacridineT44.0X1T44.0X2T44.0X3T44.0X4T44.0X5T44.0X6

Patient EducationClinical

Drug Reactions

Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions, such as drug interactions, side effects, and allergies.

The full article covers:

  • What is a drug interaction?
  • What are side effects?
  • What are drug allergies?
  • How can I stay safe when taking medicines?

Read the full article at MedlinePlus

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

Convert T44.0X5S to ICD-9-CMHistory

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

ICD-9-CM
909.5 Lte efct advrs efct drug
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
E941.0 Adv eff cholinergics
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 T44.0X5SOverview

Is T44.0X5S (Adverse effect of anticholinesterase agents) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report adverse effect of anticholinesterase agents, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T44.0X5S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the adverse effect of anticholinesterase agents itself has resolved, not the original event.

What MS-DRG does T44.0X5S group to?

On inpatient claims, adverse effect of anticholinesterase agents, sequela maps to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

Can T44.0X5S be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because adverse effect of anticholinesterase agents, sequela describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is T44.0X5S 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 adverse effect of anticholinesterase agents, sequela on inpatient claims.

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.