2026 ICD-10-CM Diagnosis Code T36.AX3A

Poisoning by fluoroquinolone antibiotics, assault, initial encounter

ICD-10-CM Code:
T36.AX3A
ICD-10 Code for:
Poisoning by fluoroquinolone antibiotics, assault, init
Is Billable?
Yes - Valid for Submission
Code Navigator:

T36.AX3A is a billable diagnosis code used to specify a medical diagnosis of poisoning by fluoroquinolone antibiotics, assault, initial encounter. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

T36.AX3A is an initial encounter code, includes a 7th character and should be used while the patient is receiving active treatment for a condition like poisoning by fluoroquinolone antibiotics assault. According to ICD-10-CM Guidelines an "initial encounter" doesn't necessarily means "initial visit". The 7th character should be used when the patient is undergoing active treatment regardless if new or different providers saw the patient over the course of a treatment. The appropriate 7th character codes should also be used even if the patient delayed seeking treatment for a condition.

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    S00–T88
    • Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
      T36-T50
      • Poisoning by, adverse effect of and underdosing of systemic antibiotics
        T36

Coding Guidelines

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 aplicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

New 2026 ICD-10-CM Code

T36.AX3A is new to ICD-10-CM code set for the FY 2026, effective October 1, 2025. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2025. This is a new and revised code for the FY 2026 (October 1, 2025 - September 30, 2026).

Replacement Code

T36AX3A replaces the following previously assigned ICD-10-CM code(s):

  • T36.8X3A - Poisoning by oth systemic antibiotics, assault, init encntr

Table of Drugs and Chemicals

The parent code T36.AX3 of the current diagnosis code is referenced in the Table of Drugs and Chemicals, this table contains a classification of drugs, industrial solvents, corrosive gases, noxious plants, pesticides, and other toxic agents.

According to ICD-10-CM coding guidelines it is advised to do not code directly from the Table of Drugs and Chemicals, instead always refer back to the Tabular List when doing the initial coding. Each substance in the table is assigned a code according to the poisoning classification and external causes of adverse effects. It is important to use as many codes as necessary to specify all reported drugs, medicinal or chemical substances. If the same diagnosis code describes the causative agent for more than one adverse reaction, poisoning, toxic effect or underdosing, utilize the code only once.

Substance Poisoning
Accidental
(unintentional)
Poisoning
Accidental
(self-harm)
Poisoning
Assault
Poisoning
Undetermined
Adverse
effect
Underdosing
Fluoroquinolone antibioticsT36.AX1T36.AX2T36.AX3T36.AX4T36.AX5T36.AX6

Code History

  • FY 2026 - Code Added, effective from 10/1/2025 through 9/30/2026