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  6. 2026 ICD-10-CM Code T36.AX

2026 ICD-10-CM Diagnosis Code T36.AX

Poisoning by, adverse effect of and underdosing of fluoroquinolone antibiotics

ICD-10-CM Code:
T36.AX
ICD-10 Code for:
Fluoroquinolone antibiotics
Is Billable?
Not Valid for Submission
Code Navigator:

T36.AX is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of poisoning by, adverse effect of and underdosing of fluoroquinolone antibiotics. The code is not specific and is NOT valid for the year 2026 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Fluoroquinolone antibiotics

Non-specific codes like T36.AX require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for fluoroquinolone antibiotics:

  • T36.AX1 for Poisoning by fluoroquinolone antibiotics, accidental (unintentional) - NON-BILLABLE CODE

  • Use T36.AX1A for initial encounter - BILLABLE CODE

  • Use T36.AX1D for subsequent encounter - BILLABLE CODE

  • Use T36.AX1S for sequela - BILLABLE CODE

  • T36.AX2 for Poisoning by fluoroquinolone antibiotics, intentional self-harm - NON-BILLABLE CODE

  • Use T36.AX2A for initial encounter - BILLABLE CODE

  • Use T36.AX2D for subsequent encounter - BILLABLE CODE

  • Use T36.AX2S for sequela - BILLABLE CODE

  • T36.AX3 for Poisoning by fluoroquinolone antibiotics, assault - NON-BILLABLE CODE

  • Use T36.AX3A for initial encounter - BILLABLE CODE

  • Use T36.AX3D for subsequent encounter - BILLABLE CODE

  • Use T36.AX3S for sequela - BILLABLE CODE

  • T36.AX4 for Poisoning by fluoroquinolone antibiotics, undetermined - NON-BILLABLE CODE

  • Use T36.AX4A for initial encounter - BILLABLE CODE

  • Use T36.AX4D for subsequent encounter - BILLABLE CODE

  • Use T36.AX4S for sequela - BILLABLE CODE

  • T36.AX5 for Adverse effect of fluoroquinolone antibiotics - NON-BILLABLE CODE

  • Use T36.AX5A for initial encounter - BILLABLE CODE

  • Use T36.AX5D for subsequent encounter - BILLABLE CODE

  • Use T36.AX5S for sequela - BILLABLE CODE

  • T36.AX6 for Underdosing of fluoroquinolone antibiotics - NON-BILLABLE CODE

  • Use T36.AX6A for initial encounter - BILLABLE CODE

  • Use T36.AX6D for subsequent encounter - BILLABLE CODE

  • Use T36.AX6S for sequela - BILLABLE CODE

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

Code History

  • FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026