2026 ICD-10-CM Diagnosis Code T46Poisoning by, adverse effect of and underdosing of agents primarily affecting the cardiovascular system
T46 is a non-billable ICD-10-CM category code for poisoning by, adverse effect of and underdosing of agents primarily affecting the cardiovascular system, so it cannot be submitted on claims. Use a more specific code from this category instead, such as T46.0X1A, T46.0X1D, T46.0X1S, and T46.0X2A.
Code Identity
Code Classification
Specific Coding for Agents primarily affecting the cardiovascular systemOverview
Non-specific codes like T46 require more characters. Use one of these billable codes instead:
T46.0 for Poisoning by, adverse effect of and underdosing of cardiac-stimulant glycosides and drugs of similar action
T46.0X for Poisoning by, adverse effect of and underdosing of cardiac-stimulant glycosides and drugs of similar action
T46.1 for Poisoning by, adverse effect of and underdosing of calcium-channel blockers
T46.1X for Poisoning by, adverse effect of and underdosing of calcium-channel blockers
T46.2 for Poisoning by, adverse effect of and underdosing of other antidysrhythmic drugs, not elsewhere classified
T46.2X for Poisoning by, adverse effect of and underdosing of other antidysrhythmic drugs
T46.3 for Poisoning by, adverse effect of and underdosing of coronary vasodilators
T46.3X for Poisoning by, adverse effect of and underdosing of coronary vasodilators
T46.4 for Poisoning by, adverse effect of and underdosing of angiotensin-converting-enzyme inhibitors
T46.4X for Poisoning by, adverse effect of and underdosing of angiotensin-converting-enzyme inhibitors
T46.5 for Poisoning by, adverse effect of and underdosing of other antihypertensive drugs
T46.5X for Poisoning by, adverse effect of and underdosing of other antihypertensive drugs
T46.6 for Poisoning by, adverse effect of and underdosing of antihyperlipidemic and antiarteriosclerotic drugs
T46.6X for Poisoning by, adverse effect of and underdosing of antihyperlipidemic and antiarteriosclerotic drugs
T46.7 for Poisoning by, adverse effect of and underdosing of peripheral vasodilators
T46.7X for Poisoning by, adverse effect of and underdosing of peripheral vasodilators
T46.8 for Poisoning by, adverse effect of and underdosing of antivaricose drugs, including sclerosing agents
T46.8X for Poisoning by, adverse effect of and underdosing of antivaricose drugs, including sclerosing agents
T46.9 for Poisoning by, adverse effect of and underdosing of other and unspecified agents primarily affecting the cardiovascular system
T46.90 for Poisoning by, adverse effect of and underdosing of unspecified agents primarily affecting the cardiovascular system
T46.99 for Poisoning by, adverse effect of and underdosing of other agents primarily affecting the cardiovascular 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 agents primarily affecting the cardiovascular system (T46). 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.
Type 1 Excludes
- poisoning by, adverse effect of and underdosing of metaraminol T44.4
7th Character Note
- The appropriate 7th character is to be added to each code from category T46
7th Character
- A - initial encounter
- D - subsequent encounter
- S - sequela
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
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.
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Drug Reactions
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Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Code HistoryHistory
Questions About T46Overview
Is T46 a billable code?
No. This is a category header that groups the codes for poisoning by, adverse effect of and underdosing of agents primarily affecting the cardiovascular system, and headers cannot be submitted on claims. Claims for poisoning by, adverse effect of and underdosing of agents primarily affecting the cardiovascular system need a more specific code from this category, such as T46.0X1A, T46.0X1D, and T46.0X1S.
