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  6. 2025 ICD-10-CM Code T45.AX5

2025 ICD-10-CM Diagnosis Code T45.AX5

Adverse effect of immune checkpoint inhibitors and immunostimulant drugs

ICD-10-CM Code:
T45.AX5
ICD-10 Code for:
Adverse effect of immune checkpoint inhibtr/immunostim drugs
Is Billable?
Not Valid for Submission
Code Navigator:

T45.AX5 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of adverse effect of immune checkpoint inhibitors and immunostimulant drugs. The code is not specific and is NOT valid for the year 2025 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 Adverse effect of immune checkpoint inhibtr/immunostim drugs

Non-specific codes like T45.AX5 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 adverse effect of immune checkpoint inhibtr/immunostim drugs:

  • Use T45.AX5A for initial encounter - BILLABLE CODE

  • Use T45.AX5D for subsequent encounter - BILLABLE CODE

  • Use T45.AX5S 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 primarily systemic and hematological agents, not elsewhere classified
        T45

Coding Guidelines

When coding an adverse effect of a drug that has been correctly prescribed and properly administered, assign the appropriate code for the nature of the adverse effect followed by the appropriate code for the adverse effect of the drug.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified (T45). Use the following options for the aplicable episode of care:

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

New 2025 ICD-10-CM Code

T45.AX5 is new to ICD-10-CM code set for the FY 2025, effective October 1, 2024. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2024. This is a new and revised code for the FY 2025 (October 1, 2024 - September 30, 2025).

Table of Drugs and Chemicals

The 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
ImmuneT45.AX1T45.AX2T45.AX3T45.AX4T45.AX5T45.AX6
Immune
  »checkpoint inhibitors
T45.AX1T45.AX2T45.AX3T45.AX4T45.AX5T45.AX6
Immune
  »globulin
T45.AX1T45.AX2T45.AX3T45.AX4T45.AX5T45.AX6
Immune
  »serum globulin
T45.AX1T45.AX2T45.AX3T45.AX4T45.AX5T45.AX6
Immunostimulant drugT45.AX1T45.AX2T45.AX3T45.AX4T45.AX5T45.AX6

Code History