2026 ICD-10-CM Diagnosis Code T46.3X3APoisoning by coronary vasodilators, assault, initial encounter

ICD-10-CM CodesS00–T88T36-T50T46

ICD-10-CM T46.3X3A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T46.3X3A is a billable ICD-10-CM diagnosis code for poisoning by coronary vasodilators, assault, 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, assault; External cause codes: poisoning by drug; and Poisoning by drugs, initial encounter.

Code Identity

ICD-10-CM Code
T46.3X3A
Billable Status
Yes — Valid for Submission
Code Describes
Poisoning by coronary vasodilators, assault, initial encounter
Short Description
Poisoning by coronary vasodilators, assault, init encntr
Parent Code
Poisoning by coronary vasodilators, assault

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
CategoryT46Poisoning by, adverse effect of and underdosing of agents primarily affecting the cardiovascular system
This CodeT46.3X3APoisoning by coronary vasodilators, assault, initial encounter

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.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR EXT022
External cause codes: intent of injury, assault
Default principal diagnosis: inpatient No · outpatient No
CCSR EXT014
External cause codes: poisoning by drug
Default principal diagnosis: inpatient No · outpatient No
CCSR INJ022
Poisoning by drugs, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Chromonar

    a coronary vasodilator agent.
  • Dilazep

    coronary vasodilator with some antiarrhythmic activity.
  • Aspirin, Dipyridamole Drug Combination

    a drug combination of aspirin and dipyridamole that functions as a platelet aggregation inhibitor, used to prevent thrombosis and stroke in transient ischemic attack patients.
  • Dipyridamole

    a phosphodiesterase inhibitor that blocks uptake and metabolism of adenosine by erythrocytes and vascular endothelial cells. dipyridamole also potentiates the antiaggregating action of prostacyclin. (from ama drug evaluations annual, 1994, p752)
  • Erythrityl Tetranitrate

    a vasodilator with general properties similar to nitroglycerin. (from martindale, the extra pharmacopoeia, 30th ed, p1020)
  • Heptaminol

    an amino alcohol that has been used as a myocardial stimulant and vasodilator and to relieve bronchospasm. its most common therapeutic use is in orthostatic hypotension. the mechanism of heptaminol's therapeutic actions is not well understood although it has been suggested to affect catecholamine release or calcium metabolism.
  • Hexobendine

    a potent vasoactive agent that dilates cerebral and coronary arteries, but slightly constricts femoral arteries, without any effects on heart rate, blood pressure or cardiac output.
  • Isosorbide Dinitrate

    a vasodilator used in the treatment of angina pectoris. its actions are similar to nitroglycerin but with a slower onset of action.
  • Khellin

    a vasodilator that also has bronchodilatory action. it has been employed in the treatment of angina pectoris, in the treatment of asthma, and in conjunction with ultraviolet light a, has been tried in the treatment of vitiligo. (from martindale, the extra pharmacopoeia, 30th ed, p1024)
  • Molsidomine

    a morpholinyl sydnone imine ethyl ester, having a nitrogen in place of the keto oxygen. it acts as nitric oxide donors and is a vasodilator that has been used in angina pectoris.
  • Nicorandil

    a derivative of the niacinamide that is structurally combined with an organic nitrate. it is a potassium-channel opener that causes vasodilatation of arterioles and large coronary arteries. its nitrate-like properties produce venous vasodilation through stimulation of guanylate cyclase.
  • Oxyfedrine

    a drug used in the treatment of angina pectoris, heart failure, conduction defects, and myocardial infarction. it is a partial agonist at beta adrenergic receptors and acts as a coronary vasodilator and cardiotonic agent.
  • Prenylamine

    a drug formerly used in the treatment of angina pectoris but superseded by less hazardous drugs. prenylamine depletes myocardial catecholamine stores and has some calcium channel blocking activity. (from martindale, the extra pharmacopoeia, 30th ed, p1406)
  • Trapidil

    a coronary vasodilator agent.

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
AmikhellineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
BendazolT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
BenziodaroneT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
CarbocromenT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
ChromonarT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Coronary vasodilator NECT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
CromonarT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
DiisopropylamineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
DilazepT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
DimoxylineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
DioxylineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
DipyridamoleT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
EfloxateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Eritrityl tetranitrateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Erythrityl tetranitrateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Erythrol tetranitrateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
EtafenoneT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
FenalcomineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
FluorosolT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
HeptaminolT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
HexadilineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
HexadylamineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
HexobendineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
IpriflavoneT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Isoamyl nitriteT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Isosorbide dinitrateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Itramin tosilateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
KhellinT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
KhellosideT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
MolsidomineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
NicorandilT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Nitrate, organicT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Nitrite, amyl (medicinal) (vapor)T46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Nitroglycerin, nitro-glycerol (medicinal)T46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Nitroglycerin, nitro-glycerol (medicinal)::nonmedicinalT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Nitroglycerin, nitro-glycerol (medicinal)::nonmedicinal::fumesT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Octyl nitriteT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Organonitrate NECT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
OxyfedrineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
PentaerythritolT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Pentaerythritol::chloralT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Pentaerythritol::tetranitrate NECT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Pentaerythrityl tetranitrateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
PentrinatT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
PerhexileneT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Perhexiline (maleate)T46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
PeritrateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
PiridoxilateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
PrenylamineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
PropatylnitrateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Sorbide nitrateT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Sweet niter spiritT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
TenitramineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
TerodilineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
TrapidilT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
TrinitrineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Trolnitrate (phosphate)T46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
VasodilatorT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Vasodilator::coronary NECT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
Vasodilator::peripheral NECT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6
VisnadineT46.3X1T46.3X2T46.3X3T46.3X4T46.3X5T46.3X6

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 T46.3X3A to ICD-9-CMHistory

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

ICD-9-CM
972.4 Pois-coronary vasodilat
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
E962.0 Assault-pois w medic agt
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 T46.3X3AOverview

Is T46.3X3A (Poisoning by coronary vasodilators, assault) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by coronary vasodilators, assault, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T46.3X3A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by coronary vasodilators, assault, such as an emergency visit or first evaluation.

What MS-DRG does T46.3X3A group to?

When poisoning by coronary vasodilators, assault, 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 T46.3X3A?

Under the General Equivalence Mappings, poisoning by coronary vasodilators, assault, initial encounter converts to ICD-9-CM 972.4 (pois-coronary vasodilat) and E962.0 (assault-pois w medic agt). 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.