2026 ICD-10-CM Diagnosis Code T44.3X4APoisoning by other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics, undetermined, initial encounter
T44.3X4A is a billable ICD-10-CM diagnosis code for poisoning by other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics, undetermined, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, undetermined; External cause codes: poisoning by drug; and Poisoning by drugs, initial encounter.
Code Identity
Code Classification
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
Atropine
an alkaloid, originally from atropa belladonna, but found in other plants, mainly solanaceae. hyoscyamine is the 3(s)-endo isomer of atropine.Atropine Derivatives
analogs and derivatives of atropine.Hyoscyamine
the 3(s)-endo isomer of atropine.Benactyzine
a centrally acting muscarinic antagonist. benactyzine has been used in the treatment of depression and is used in research to investigate the role of cholinergic systems on behavior.Benztropine
a centrally active muscarinic antagonist that has been used in the symptomatic treatment of parkinson disease. benztropine also inhibits the uptake of dopamine.Biperiden
a muscarinic antagonist that has effects in both the central and peripheral nervous systems. it has been used in the treatment of arteriosclerotic, idiopathic, and postencephalitic parkinsonism. it has also been used to alleviate extrapyramidal symptoms induced by phenothiazine derivatives and reserpine.Cyclopentolate
a parasympatholytic anticholinergic used solely to obtain mydriasis or cycloplegia.Dexetimide
a muscarinic antagonist that has been used to treat neuroleptic-induced parkinsonism. benzetimide is the (-)-enantimorph of dexetimide.Dicyclomine
a muscarinic antagonist used as an antispasmodic and in urinary incontinence. it has little effect on glandular secretion or the cardiovascular system. it does have some local anesthetic properties and is used in gastrointestinal, biliary, and urinary tract spasms.Dyphylline
a theophylline derivative with broncho- and vasodilator properties. it is used in the treatment of asthma, cardiac dyspnea, and bronchitis.Flavoxate
a drug that has been used in various urinary syndromes and as an antispasmodic. its therapeutic usefulness and its mechanism of action are not clear. it may have local anesthetic activity and direct relaxing effects on smooth muscle as well as some activity as a muscarinic antagonist.Gefarnate
a water insoluble terpene fatty acid used in the treatment of gastrointestinal ulcers; it facilitates the healing and function of mucosal tissue.Glycopyrrolate
a muscarinic antagonist used as an antispasmodic, in some disorders of the gastrointestinal tract, and to reduce salivation with some anesthetics.Hyoscyamus
a plant genus of the family solanaceae which contains tropanes.Methantheline
a quaternary ammonium compound that acts as an antimuscarinic agent. it has been used in the treatment of peptic ulcer, in gastrointestinal disorders associated with smooth muscle spasm, and in the management of urinary incontinence, and may also be used for the treatment of hyperhidrosis.Papaverine
an alkaloid found in opium but not closely related to the other opium alkaloids in its structure or pharmacological actions. it is a direct-acting smooth muscle relaxant used in the treatment of impotence and as a vasodilator, especially for cerebral vasodilation. the mechanism of its pharmacological actions is not clear, but it apparently can inhibit phosphodiesterases and it may have direct actions on calcium channels.Procyclidine
a muscarinic antagonist that crosses the blood-brain barrier and is used in the treatment of drug-induced extrapyramidal disorders and in parkinsonism.Propantheline
a muscarinic antagonist used as an antispasmodic, in rhinitis, in urinary incontinence, and in the treatment of ulcers. at high doses it has nicotinic effects resulting in neuromuscular blocking.Butylscopolammonium Bromide
antimuscarinic quaternary ammonium derivative of scopolamine used to treat cramps in gastrointestinal, urinary, uterine, and biliary tracts, and to facilitate radiologic visualization of the gastrointestinal tract.N-Methylscopolamine
a muscarinic antagonist used to study binding characteristics of muscarinic cholinergic receptors.Scopolamine
an alkaloid from solanaceae, especially datura and scopolia. scopolamine and its quaternary derivatives act as antimuscarinics like atropine, but may have more central nervous system effects. its many uses include an anesthetic premedication, the treatment of urinary incontinence and motion sickness, an antispasmodic, and a mydriatic and cycloplegic.Scopolamine Derivatives
analogs or derivatives of scopolamine.Tolperisone
a centrally acting muscle relaxant that has been used for the symptomatic treatment of spasticity and muscle spasm. (from martindale, the extra pharmacopoeia, 30th ed, p1211)Trihexyphenidyl
one of the centrally acting muscarinic antagonists used for treatment of parkinsonian disorders and drug-induced extrapyramidal movement disorders and as an antispasmodic.Trimebutine
proposed spasmolytic with possible local anesthetic action used in gastrointestinal disorders.Tropicamide
one of the muscarinic antagonists with pharmacologic action similar to atropine and used mainly as an ophthalmic parasympatholytic or mydriatic.
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
Poisoning
A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be poisonous if too much is taken. Poisons can include:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T44.3X4A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T44.3X4AOverview
Is T44.3X4A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics, undetermined, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T44.3X4A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics, undetermined, such as an emergency visit or first evaluation.
What MS-DRG does T44.3X4A group to?
When poisoning by other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics, undetermined, 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 T44.3X4A?
Under the General Equivalence Mappings, poisoning by other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics, undetermined, initial encounter converts to ICD-9-CM 971.1 (pois-parasympatholytics) and E980.4 (undet pois-med agnt 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.
