2026 ICD-10-CM Diagnosis Code T45Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified

ICD-10-CM Codes›S00–T88›T36-T50›T45

ICD-10-CM T45
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T45 is a non-billable ICD-10-CM category code for poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified, so it cannot be submitted on claims. Use a more specific code from this category instead, such as T45.0X1A, T45.0X1D, T45.0X1S, and T45.0X2A.

Code Identity

ICD-10-CM Code
T45
Billable Status
No — Non-Billable Category
Code Describes
Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified
Chapter
T36-T50
Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT36-T50Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
CategoryT45Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified
This CodeT45Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified

Specific Coding for Primarily systemic and hematological agents, NECOverview

Non-specific codes like T45 require more characters. Use one of these billable codes instead:

  • T45.0 for Poisoning by, adverse effect of and underdosing of antiallergic and antiemetic drugs

  • T45.0X for Poisoning by, adverse effect of and underdosing of antiallergic and antiemetic drugs

  • T45.1 for Poisoning by, adverse effect of and underdosing of antineoplastic and immunosuppressive drugs

  • T45.1X for Poisoning by, adverse effect of and underdosing of antineoplastic and immunosuppressive drugs

  • T45.2 for Poisoning by, adverse effect of and underdosing of vitamins

  • T45.2X for Poisoning by, adverse effect of and underdosing of vitamins

  • T45.3 for Poisoning by, adverse effect of and underdosing of enzymes

  • T45.3X for Poisoning by, adverse effect of and underdosing of enzymes

  • T45.4 for Poisoning by, adverse effect of and underdosing of iron and its compounds

  • T45.4X for Poisoning by, adverse effect of and underdosing of iron and its compounds

  • T45.5 for Poisoning by, adverse effect of and underdosing of anticoagulants and antithrombotic drugs

  • T45.51 for Poisoning by, adverse effect of and underdosing of anticoagulants

  • T45.52 for Poisoning by, adverse effect of and underdosing of antithrombotic drugs

  • T45.6 for Poisoning by, adverse effect of and underdosing of fibrinolysis-affecting drugs

  • T45.60 for Poisoning by, adverse effect of and underdosing of unspecified fibrinolysis-affecting drugs

  • T45.61 for Poisoning by, adverse effect of and underdosing of thrombolytic drugs

  • T45.62 for Poisoning by, adverse effect of and underdosing of hemostatic drugs

  • T45.69 for Poisoning by, adverse effect of and underdosing of other fibrinolysis-affecting drugs

  • T45.7 for Poisoning by, adverse effect of and underdosing of anticoagulant antagonists, vitamin K and other coagulants

  • T45.7X for Poisoning by, adverse effect of and underdosing of anticoagulant antagonists, vitamin K and other coagulants

  • T45.8 for Poisoning by, adverse effect of and underdosing of other primarily systemic and hematological agents

  • T45.8X for Poisoning by, adverse effect of and underdosing of other primarily systemic and hematological agents

  • T45.9 for Poisoning by, adverse effect of and underdosing of unspecified primarily systemic and hematological agent

  • T45.91 for Poisoning by unspecified primarily systemic and hematological agent, accidental (unintentional)

  • T45.92 for Poisoning by unspecified primarily systemic and hematological agent, intentional self-harm

  • T45.93 for Poisoning by unspecified primarily systemic and hematological agent, assault

  • T45.94 for Poisoning by unspecified primarily systemic and hematological agent, undetermined

  • T45.95 for Adverse effect of unspecified primarily systemic and hematological agent

  • T45.96 for Underdosing of unspecified primarily systemic and hematological agent

  • T45.A for Poisoning by, adverse effect of and underdosing of immune checkpoint inhibitors and immunostimulant drugs

  • T45.AX for Poisoning by, adverse effect of and underdosing of immune checkpoint inhibitors and immunostimulant drugs

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 primarily systemic and hematological agents, not elsewhere classified (T45). 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.

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

7th Character Note

  • The appropriate 7th character is to be added to each code from category T45

7th Character

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

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T45Overview

Is T45 a billable code?

No. This is a category header that groups the codes for poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified, and headers cannot be submitted on claims. Claims for poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified need a more specific code from this category, such as T45.0X1A, T45.0X1D, and T45.0X1S.