ICD-10-CM 2027 diagnosis code
T45.5Poisoning by, adverse effect of and underdosing of anticoagulants and antithrombotic drugs
T45.5 is a header code, so it can't be reported by itself. Choose one of the 2 more specific codes beneath it and add the required 7th character.Short description: Anticoagulants and antithrombotic drugs
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About T45.5
T45.5 is the ICD-10-CM diagnosis code for poisoning by, adverse effect of and underdosing of anticoagulants and antithrombotic drugs. It belongs to category T45 (poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified), block T36-T50 (poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.
Within T45 (poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified), T45.5 is specifically for poisoning by, adverse effect of and underdosing of anticoagulants and antithrombotic drugs. Related codes cover antiallergic and antiemetic drugs (T45.0), antineoplastic and immunosuppressive drugs (T45.1), vitamins (T45.2), enzymes (T45.3), iron and its compounds (T45.4), fibrinolysis-affecting drugs (T45.6), anticoagulant antagonists, vitamin K and other coagulants (T45.7), other primarily systemic and hematological agents (T45.8) and 2 more.
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
7th character
The appropriate 7th character is to be added to each code from category T45
- T45.51Poisoning by, adverse effect of and underdosing of anticoagulants
- T45.52Poisoning by, adverse effect of and underdosing of antithrombotic drugs
- T45.521Poisoning by antithrombotic drugs, accidental (unintentional)
- T45.522Poisoning by antithrombotic drugs, intentional self-harm
- T45.523Poisoning by antithrombotic drugs, assault
- T45.524Poisoning by antithrombotic drugs, undetermined
- T45.525Adverse effect of antithrombotic drugs
- T45.526Underdosing of antithrombotic drugs
- Ainitial encounter
- Dsubsequent encounter
- Ssequela
Notes that apply from higher levels
Instructions written at a parent level also apply to T45.5.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about T45.5
Is T45.5 billable?
- No. T45.5 is a header code. Report one of its more specific subcodes instead.