T65.824Header code — not billable

Toxic effect of harmful algae and algae toxins, undetermined

Chapter
19. Injury, poisoning and certain other consequences of external causes
Category
T65
Effective date
October 1, 2026

Related codes in category T65

Frequently asked questions

What is ICD-10 code T65.824?

T65.824 is an ICD-10-CM diagnosis code for Toxic effect of harmful algae and algae toxins, undetermined.

Is T65.824 a billable code?

No. T65.824 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 T65.824 in?

T65.824 falls under Chapter 19: Injury, poisoning and certain other consequences of external causes.

When did T65.824 become effective?

T65.824 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to T65.824?

T65.824 belongs to category T65, 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.