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ICD-10/T65.851A

T65.851A ICD-10-CM Code: Toxic effect of medetomidine, accidental (unintentional), initial encounter

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Code Set: New for FY2027 — not valid before October 1, 2026.

Official Registry Overview & Definition

No additional overview provided for this record.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T65.851A in the official ICD-10-CM tabular list.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Toxic effect of medetomidine NOS

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code to identify associated manifestations, such as:
  • bradycardia NOS (R00.1)
  • somnolence, stupor and coma (R40.-)
  • Use additional 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.-)

Change history

  • FY2027 — 2026-10-01
    Added to the code set
    Toxic effect of medetomidine, accidental (unintentional), initial encounter
    FY2027 changes

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.

Contextual Map

Every relationship of T65.851A in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

  • S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88) [Hierarchy]
  • T51-T65 — Toxic effects of substances chiefly nonmedicinal as to source [Hierarchy]

Drugs & chemicals

  • Medetomidine — Medetomidine — Poisoning, Accidental (unintentional) [Drug table]: “Medetomidine (Poisoning, Accidental (unintentional))”

Nearest codes (40)

  • T65 — Toxic effect of other and unspecified substances [Sibling]
  • T65.834S — Toxic effect of fiberglass, undetermined, sequela [Sibling]
  • T65.84 — Toxic effect of xylazine [Sibling]
  • T65.841 — Toxic effect of xylazine, accidental (unintentional) [Sibling]
  • T65.841A — Toxic effect of xylazine, accidental (unintentional), initial encounter [Sibling]
  • T65.841D — Toxic effect of xylazine, accidental (unintentional), subsequent encounter [Sibling]
  • T65.841S — Toxic effect of xylazine, accidental (unintentional), sequela [Sibling]
  • T65.842 — Toxic effect of xylazine, intentional self-harm [Sibling]
  • and 32 more

Change history

  • FY2027 — Added to the code set [Change history]

Frequently Asked Questions (FAQ) & Clinical Guidance

Does T65.851A require a 7th character?

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T65.851A in its code family, with their registry titles.

  • T65.844A — Toxic effect of xylazine, undetermined, initial encounter
  • T65.844D — Toxic effect of xylazine, undetermined, subsequent encounter
  • T65.844S — Toxic effect of xylazine, undetermined, sequela
  • T65.85 — Toxic effect of medetomidine
  • T65.851 — Toxic effect of medetomidine, accidental (unintentional)
  • T65.851D — Toxic effect of medetomidine, accidental (unintentional), subsequent encounter
  • T65.851S — Toxic effect of medetomidine, accidental (unintentional), sequela
  • T65.852 — Toxic effect of medetomidine, intentional self-harm
  • T65.852A — Toxic effect of medetomidine, intentional self-harm, initial encounter
  • T65.852D — Toxic effect of medetomidine, intentional self-harm, subsequent encounter

View all codes in the T65 family

Associated Substances (1)

Substances from the official ICD-10-CM Table of Drugs and Chemicals that map to this code.

  • Medetomidine