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ICD-10-CM 2027 diagnosis code

T40.415Adverse effect of fentanyl or fentanyl analogs

Not billable — use a more specific codeRequires 7th character

T40.415 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it and add the required 7th character.

Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS, effective October 1, 2026. Updated September 29, 2026. About our data

About T40.415

T40.415 is the ICD-10-CM diagnosis code for adverse effect of fentanyl or fentanyl analogs. It belongs to category T40 (poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens]), 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 3 subcodes must be used instead.

Within T40.41 (poisoning by, adverse effect of and underdosing of fentanyl or fentanyl analogs), T40.415 is specifically for adverse effect of fentanyl or fentanyl analogs. Related codes cover poisoning by fentanyl or fentanyl analogs, accidental (unintentional) (T40.411), poisoning by fentanyl or fentanyl analogs, intentional self-harm (T40.412), poisoning by fentanyl or fentanyl analogs, assault (T40.413), poisoning by fentanyl or fentanyl analogs, undetermined (T40.414) and underdosing of fentanyl or fentanyl analogs (T40.416).

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 was added in FY2021, effective October 1, 2020.

7th character

The appropriate 7th character is to be added to each code from category T40

Notes that apply from higher levels

Instructions written at a parent level also apply to T40.415.

Table of Drugs & Neoplasms entries

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2021 (effective 10/1/2020): Added
  • No changes since FY2021.

Common questions about T40.415

Is T40.415 billable?

No. T40.415 is a header code. Report one of its more specific subcodes instead.