T40.416Header code — not billable

Underdosing of fentanyl or fentanyl analogs

Chapter
19. Injury, poisoning and certain other consequences of external causes
Category
T40
Effective date
October 1, 2026

Related codes in category T40

Frequently asked questions

What is ICD-10 code T40.416?

T40.416 is an ICD-10-CM diagnosis code for Underdosing of fentanyl or fentanyl analogs.

Is T40.416 a billable code?

No. T40.416 is a category/header code, not billable on its own — use one of its more specific child codes instead.

What ICD-10-CM chapter is T40.416 in?

T40.416 falls under Chapter 19: Injury, poisoning and certain other consequences of external causes.

When did T40.416 become effective?

T40.416 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to T40.416?

T40.416 belongs to category T40, which includes 12 other codes — see the related codes list on this page.

ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.