2026 ICD-10-CM Diagnosis Code T44Poisoning by, adverse effect of and underdosing of drugs primarily affecting the autonomic nervous system
T44 is a non-billable ICD-10-CM category code for poisoning by, adverse effect of and underdosing of drugs primarily affecting the autonomic nervous system, so it cannot be submitted on claims. Use a more specific code from this category instead, such as T44.0X1A, T44.0X1D, T44.0X1S, and T44.0X2A.
Code Identity
Code Classification
Specific Coding for Drugs primarily affecting the autonomic nervous systemOverview
Non-specific codes like T44 require more characters. Use one of these billable codes instead:
T44.0 for Poisoning by, adverse effect of and underdosing of anticholinesterase agents
T44.0X for Poisoning by, adverse effect of and underdosing of anticholinesterase agents
T44.1 for Poisoning by, adverse effect of and underdosing of other parasympathomimetics [cholinergics]
T44.1X for Poisoning by, adverse effect of and underdosing of other parasympathomimetics [cholinergics]
T44.2 for Poisoning by, adverse effect of and underdosing of ganglionic blocking drugs
T44.2X for Poisoning by, adverse effect of and underdosing of ganglionic blocking drugs
T44.3 for Poisoning by, adverse effect of and underdosing of other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics
T44.3X for Poisoning by, adverse effect of and underdosing of other parasympatholytics [anticholinergics and antimuscarinics] and spasmolytics
T44.4 for Poisoning by, adverse effect of and underdosing of predominantly alpha-adrenoreceptor agonists
T44.4X for Poisoning by, adverse effect of and underdosing of predominantly alpha-adrenoreceptor agonists
T44.5 for Poisoning by, adverse effect of and underdosing of predominantly beta-adrenoreceptor agonists
T44.5X for Poisoning by, adverse effect of and underdosing of predominantly beta-adrenoreceptor agonists
T44.6 for Poisoning by, adverse effect of and underdosing of alpha-adrenoreceptor antagonists
T44.6X for Poisoning by, adverse effect of and underdosing of alpha-adrenoreceptor antagonists
T44.7 for Poisoning by, adverse effect of and underdosing of beta-adrenoreceptor antagonists
T44.7X for Poisoning by, adverse effect of and underdosing of beta-adrenoreceptor antagonists
T44.8 for Poisoning by, adverse effect of and underdosing of centrally-acting and adrenergic-neuron- blocking agents
T44.8X for Poisoning by, adverse effect of and underdosing of centrally-acting and adrenergic- neuron-blocking agents
T44.9 for Poisoning by, adverse effect of and underdosing of other and unspecified drugs primarily affecting the autonomic nervous system
T44.90 for Poisoning by, adverse effect of and underdosing of unspecified drugs primarily affecting the autonomic nervous system
T44.99 for Poisoning by, adverse effect of and underdosing of other drugs primarily affecting the autonomic nervous system
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.
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
7th Character Note
- The appropriate 7th character is to be added to each code from category T44
7th Character
- A - initial encounter
- D - subsequent encounter
- S - sequela
Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.
Indicates that a seventh character is to be assigned to codes in a subcategory.
Patient EducationClinical
Drug Reactions
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Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Code HistoryHistory
Questions About T44Overview
Is T44 a billable code?
No. This is a category header that groups the codes for poisoning by, adverse effect of and underdosing of drugs primarily affecting the autonomic nervous system, and headers cannot be submitted on claims. Claims for poisoning by, adverse effect of and underdosing of drugs primarily affecting the autonomic nervous system need a more specific code from this category, such as T44.0X1A, T44.0X1D, and T44.0X1S.
