2026 ICD-10-CM Diagnosis Code T36.5X4APoisoning by aminoglycosides, undetermined, initial encounter
T36.5X4A is a billable ICD-10-CM diagnosis code for poisoning by aminoglycosides, 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 systemic antibiotics (T36). 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
Amikacin
a broad-spectrum antibiotic derived from kanamycin. it is reno- and oto-toxic like the other aminoglycoside antibiotics.Kanamycin Kinase
a class of enzymes that inactivate aminocyclitol-aminoglycoside antibiotics (aminoglycosides) by regiospecific phosphorylation of the 3' and/or 5' hydroxyl.Dibekacin
analog of kanamycin with antitubercular as well as broad-spectrum antimicrobial properties.Framycetin
a component of neomycin that is produced by streptomyces fradiae. on hydrolysis it yields neamine and neobiosamine b. (from merck index, 11th ed)Kanamycin
antibiotic complex produced by streptomyces kanamyceticus from japanese soil. comprises 3 components: kanamycin a, the major component, and kanamycins b and c, the minor components.Kanamycin Resistance
nonsusceptibility of bacteria to the antibiotic kanamycin, which can bind to their 70s ribosomes and cause misreading of messenger rna.Netilmicin
semisynthetic 1-n-ethyl derivative of sisomycin, an aminoglycoside antibiotic with action similar to gentamicin, but less ear and kidney toxicity.Novobiocin
an antibiotic compound derived from streptomyces niveus. it has a chemical structure similar to coumarin. novobiocin binds to dna gyrase, and blocks adenosine triphosphatase (atpase) activity. (from reynolds, martindale the extra pharmacopoeia, 30th ed, p189)Paromomycin
an aminoglycoside antibacterial and antiprotozoal agent produced by species of streptomyces.Ribostamycin
a broad-spectrum antimicrobial isolated from streptomyces ribosifidicus.Sisomicin
antibiotic produced by micromonospora inyoensis. it is closely related to gentamicin c1a, one of the components of the gentamicin complex (gentamicins).Spectinomycin
an antibiotic produced by streptomyces spectabilis. it is active against gram-negative bacteria and used for the treatment of gonorrhea.Tobramycin
an aminoglycoside, broad-spectrum antibiotic produced by streptomyces tenebrarius. it is effective against gram-negative bacteria, especially the pseudomonas species. it is a 10% component of the antibiotic complex, nebramycin, produced by the same species.Tobramycin, Dexamethasone Drug Combination
a topical preparation of tobramycin and dexamethasone that is used for treating or preventing superficial bacterial infections of the eye.
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
Antibiotics
Antibiotics are medicines that fight bacterial infections in people and animals. They work by killing the bacteria or by making it hard for the bacteria to grow and multiply.
The full article covers:
- What are antibiotics?
- What do antibiotics treat?
- Do antibiotics treat viral infections?
- What are the side effects of antibiotics?
- Why is it important to take antibiotics only when they're needed?
- How do I use antibiotics correctly?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T36.5X4A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T36.5X4AOverview
Is T36.5X4A (Poisoning by aminoglycosides, undetermined) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by aminoglycosides, undetermined, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T36.5X4A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by aminoglycosides, undetermined, such as an emergency visit or first evaluation.
What MS-DRG does T36.5X4A group to?
When poisoning by aminoglycosides, 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 T36.5X4A?
Under the General Equivalence Mappings, poisoning by aminoglycosides, undetermined, initial encounter converts to ICD-9-CM 960.8 (poisoning-antibiotic NEC) 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.
