2027 ICD-10-CM Diagnosis Code T65.85Toxic effect of medetomidine

ICD-10-CM Codes›S00–T88›T51-T65›T65

ICD-10-CM T65.85
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T65.85 is a non-billable ICD-10-CM category code for toxic effect of medetomidine, so it cannot be submitted on claims. Use a more specific code from this category instead, such as T65.851A, T65.851D, T65.851S, and T65.852A.

Code Identity

ICD-10-CM Code
T65.85
Billable Status
No — Non-Billable Category
Code Describes
Toxic effect of medetomidine
Short Description
Toxic effect of medetomidine
Same as the full description in the CMS dataset.
Parent Code
T65.8
Toxic effect of other specified substances

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT51-T65Toxic effects of substances chiefly nonmedicinal as to source
CategoryT65Toxic effect of other and unspecified substances
This CodeT65.85Toxic effect of medetomidine

Specific Coding for Toxic effect of medetomidineOverview

Non-specific codes like T65.85 require more characters. Use one of these billable codes instead:

  • T65.851 for Toxic effect of medetomidine, accidental (unintentional)

  • Use T65.851A for initial encounter

  • Use T65.851D for subsequent encounter

  • Use T65.851S for sequela

  • T65.852 for Toxic effect of medetomidine, intentional self-harm

  • Use T65.852A for initial encounter

  • Use T65.852D for subsequent encounter

  • Use T65.852S for sequela

  • T65.853 for Toxic effect of medetomidine, assault

  • Use T65.853A for initial encounter

  • Use T65.853D for subsequent encounter

  • Use T65.853S for sequela

  • T65.854 for Toxic effect of medetomidine, undetermined

  • Use T65.854A for initial encounter

  • Use T65.854D for subsequent encounter

  • Use T65.854S for sequela

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Toxic effect of other and unspecified substances (T65). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to T65.85: its own notes plus those printed at T65, block T51-T65, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block T51-T65 Toxic effects of substances chiefly nonmedicinal as to source applies to 1,680 codes
  • contact with and (suspected) exposure to toxic substances (Z77.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

On T65.85 itself
  • code to identify associated manifestations, such as:
  • bradycardia NOS (R00.1)
  • somnolence, stupor and coma (R40.-)
From Block T51-T65 Toxic effects of substances chiefly nonmedicinal as to source applies to 1,680 codes
  • 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.-)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Notes

General instructions on how these codes are used.

From Block T51-T65 Toxic effects of substances chiefly nonmedicinal as to source applies to 1,680 codes
  • 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.
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From T65 Toxic effect of other and unspecified substances applies to 192 codes
  • The appropriate 7th character is to be added to each code from category T65
Values for category T65 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Code HistoryHistory

FY 2027AddedAdded to the ICD-10-CM code setEffective October 1, 2026.
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About T65.85Overview

What is the ICD-10 code for toxic effect of medetomidine?

T65.85 (sometimes written as T6585) is the ICD-10-CM category for toxic effect of medetomidine, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is T65.85 (Toxic effect of other specified substances) a billable code?

No. This is a category header that groups the codes for toxic effect of medetomidine, and headers cannot be submitted on claims. Claims for toxic effect of medetomidine need a more specific code from this category, such as T65.851A, T65.851D, and T65.851S.

Can T65.85 be reported with a code from Z77?

Not as a rule. The Excludes1 note at block T51-T65, which applies to T65.85, lists "contact with and (suspected) exposure to toxic substances (Z77.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does T65.85 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code to identify associated manifestations, such as: bradycardia NOS (R00.1); somnolence, stupor and coma (R40.-). The additional code is reported after T65.85.