2026 ICD-10-CM Diagnosis Code T41.5X3APoisoning by therapeutic gases, assault, initial encounter
T41.5X3A is a billable ICD-10-CM diagnosis code for poisoning by therapeutic gases, 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
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 anesthetics and therapeutic gases (T41). 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
3-Hydroxyanthranilate 3,4-Dioxygenase
an enzyme that catalyzes the conversion of 3-hydroxyanthranilate to 2-amino-3-carboxymuconate semialdehyde. it was formerly characterized as ec 1.13.1.6.Biological Oxygen Demand Analysis
testing for the amount of biodegradable organic material in a water sample by measuring the quantity of oxygen consumed by biodegradation of those materials over a specific time period.Blood Gas Monitoring, Transcutaneous
the noninvasive measurement or determination of the partial pressure (tension) of oxygen and/or carbon dioxide locally in the capillaries of a tissue by the application to the skin of a special set of electrodes. these electrodes contain photoelectric sensors capable of picking up the specific wavelengths of radiation emitted by oxygenated versus reduced hemoglobin.Extracorporeal Membrane Oxygenation
application of a life support system that circulates the blood through an oxygenating system, which may consist of a pump, a membrane oxygenator, and a heat exchanger. examples of its use are to assist victims of smoke inhalation injury; respiratory failure; and cardiac failure.Heme Oxygenase (Decyclizing)
a mixed function oxidase enzyme which during hemoglobin catabolism catalyzes the degradation of heme to ferrous iron, carbon monoxide and biliverdin in the presence of molecular oxygen and reduced nadph. the enzyme is induced by metals, particularly cobalt.Heme Oxygenase-1
a ubiquitous stress-responsive enzyme that catalyzes the oxidative cleavage of heme to yield iron; carbon monoxide; and biliverdin.Homogentisate 1,2-Dioxygenase
a mononuclear fe(ii)-dependent oxygenase, this enzyme catalyzes the conversion of homogentisate to 4-maleylacetoacetate, the third step in the pathway for the catabolism of tyrosine. deficiency in the enzyme causes alkaptonuria, an autosomal recessive disorder, characterized by homogentisic aciduria, ochronosis and arthritis. this enzyme was formerly characterized as ec 1.13.1.5 and ec 1.99.2.5.Hyperbaric Oxygenation
the therapeutic intermittent administration of oxygen in a chamber at greater than sea-level atmospheric pressures (three atmospheres). it is considered effective treatment for air and gas embolisms, smoke inhalation, acute carbon monoxide poisoning, caisson disease, clostridial gangrene, etc. (from segen, dictionary of modern medicine, 1992). the list of treatment modalities includes stroke.Hypoxia
sub-optimal oxygen levels in the ambient air of living organisms.Inositol Oxygenase
a non-heme iron enzyme that catalyzes the conversion of myoinositol to d-glucuronic acid. the reaction is the first committed step in myoinositol catabolic pathway. this enzyme was formerly characterized as ec 1.13.1.11 and 1.99.2.6.Mixed Function Oxygenases
widely distributed enzymes that carry out oxidation-reduction reactions in which one atom of the oxygen molecule is incorporated into the organic substrate; the other oxygen atom is reduced and combined with hydrogen ions to form water. they are also known as monooxygenases or hydroxylases. these reactions require two substrates as reductants for each of the two oxygen atoms. there are different classes of monooxygenases depending on the type of hydrogen-providing cosubstrate (coenzymes) required in the mixed-function oxidation.Oxygen
an element with atomic symbol o, atomic number 8, and atomic weight [15.99903; 15.99977]. it is the most abundant element on earth and essential for respiration.Oxygen Compounds
inorganic compounds that contain oxygen as an integral part of the molecule.Oxygen Consumption
the rate at which oxygen is used by a tissue; microliters of oxygen stpd used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (stedman, 25th ed, p346)Oxygen Inhalation Therapy
inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (from dorland, 27th ed & stedman, 25th ed)Oxygen Isotopes
stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. o-17 and 18 are stable oxygen isotopes.Oxygen Radical Absorbance Capacity
a measure of the ability of a substance, such as a food, to quench oxygen free radicals in vitro.Oxygen Radioisotopes
unstable isotopes of oxygen that decay or disintegrate emitting radiation. o atoms with atomic weights 13, 14, 15, 19, and 20 are radioactive oxygen isotopes.Oxygen Saturation
extent to which hemoglobin is saturated with oxygen typically as measured in arterial blood. it can be measured by various methods (e.g., pulse oxymeter, blood gas analysis). a low blood oxygen saturation level indicates a condition called hypoxemia.Oxygenases
oxidases that specifically introduce dioxygen-derived oxygen atoms into a variety of organic molecules.Oxygenators
devices which mechanically oxygenate venous blood extracorporeally. they are used in combination with one or more pumps for maintaining circulation during open heart surgery and for assisting the circulation in patients seriously ill with some cardiac and pulmonary disorders. (umdns, 1999)Oxygenators, Membrane
devices in which blood and oxygen are separated by a semipermeable membrane, generally of teflon or polypropylene, across which gas exchange occurs. the membrane may be arranged as a series of parallel plates or as a number of hollow fibers; in the latter arrangement, the blood may flow inside the fibers, which are surrounded by gas, or the blood may flow outside the fibers and the gas inside the fibers. (dorland, 28th ed)Photosystem II Protein Complex
a large multisubunit protein complex found in the thylakoid membrane. it uses light energy derived from light-harvesting protein complexes to catalyze the splitting of water into dioxygen and of reducing equivalents of hydrogen.Reactive Oxygen Species
molecules or ions formed by the incomplete one-electron reduction of oxygen. these reactive oxygen intermediates include singlet oxygen; superoxides; peroxides; hydroxyl radical; and hypochlorous acid. they contribute to the microbicidal activity of phagocytes, regulation of signal transduction and gene expression, and the oxidative damage to nucleic acids; proteins; and lipids.Singlet Oxygen
an excited state of molecular oxygen generated photochemically or chemically. singlet oxygen reacts with a variety of biological molecules such as nucleic acids; proteins; and lipids; causing oxidative damages.Tryptophan Oxygenase
a dioxygenase with specificity for the oxidation of the indoleamine ring of tryptophan. it is a liver-specific enzyme that is the first and rate limiting enzyme in the kynurenine pathway of tryptophan catabolism.
Table of Drugs and ChemicalsClinical
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 T41.5X3A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T41.5X3AOverview
Is T41.5X3A (Poisoning by therapeutic gases, assault) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by therapeutic gases, assault, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T41.5X3A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by therapeutic gases, assault, such as an emergency visit or first evaluation.
What MS-DRG does T41.5X3A group to?
When poisoning by therapeutic gases, 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 T41.5X3A?
Under the General Equivalence Mappings, poisoning by therapeutic gases, assault, initial encounter converts to ICD-9-CM 975.8 (pois-respir drug NEC/NOS) 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.
