Toxic effect of harmful algae and algae toxins, undetermined

Not billableICD-10-CM diagnosis code.

This code exists but cannot be submitted on its own. It groups the more specific codes beneath it.

A category header for its whole life, FY2016 onwards. It has never been valid for submission on its own.

Submit one of these 3 more specific codes instead:

T65.824A Toxic effect of harmful algae and algae toxins, undetermined, initial encounter
T65.824D Toxic effect of harmful algae and algae toxins, undetermined, subsequent encounter
T65.824S Toxic effect of harmful algae and algae toxins, undetermined, sequela

This code requires a seventh character. See the rule below.

What has happened to this code

Every change the publisher made, from 2014 to now. Entries marked draft are from the pre-implementation releases: ICD-10 took effect on 1 October 2015, so nothing before FY2016 was ever valid on a claim.

FY2014 Added to the draft code set draft Toxic effect of harmful algae and algae toxins, undetermined

Official coding rules

Published by CDC for FY2027. A rule attached to a category binds every code beneath it, so the rules inherited from this code's ancestors are shown with the code they come from.

Inherited from T65 Toxic effect of other and unspecified substances

Seventh character required

The appropriate 7th character is to be added to each code from category T65

Inherited from the T51-T65 section Toxic effects of substances chiefly nonmedicinal as to source (T51-T65)

Excludes1 - never coded here

contact with and (suspected) exposure to toxic substances (Z77.-)

Use additional code

code(s):
for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents (J60-J70)
personal history of foreign body fully removed (Z87.821)
to identify any retained foreign body, if applicable (Z18.-)

Note

When no intent is indicated code to accidental. Undetermined intent is only for use when there is specific documentation in the record that the intent of the toxic effect cannot be determined.

How CDC's index refers to this code

Wording from the official alphabetic index. Much of it appears nowhere in the code description, which is why a search for the everyday phrase so often finds nothing.

Algae

Codes in the same group

Code	Description	Status
T65.821	Toxic effect of harmful algae and algae toxins, accidental (unintentional)	Not billable
T65.822	Toxic effect of harmful algae and algae toxins, intentional self-harm	Not billable
T65.823	Toxic effect of harmful algae and algae toxins, assault	Not billable