2026 ICD-10-CM Diagnosis Code T65.843AToxic effect of xylazine, assault, initial encounter

ICD-10-CM Codes›S00–T88›T51-T65›T65

ICD-10-CM T65.843A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T65.843A is a billable ICD-10-CM diagnosis code for toxic effect of xylazine, assault, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 917 through 918.

Code Identity

ICD-10-CM Code
T65.843A
Billable Status
Yes — Valid for Submission
Code Describes
Toxic effect of xylazine, assault, initial encounter
Short Description
Toxic effect of xylazine, assault, initial encounter
Same as the full description in the CMS dataset.
Parent Code
T65.843
Toxic effect of xylazine, assault

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 CodeT65.843AToxic effect of xylazine, assault, initial encounter

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 2026, published by CMS and the National Center for Health Statistics.

Clinical InformationClinical

  • Xylazine

    an adrenergic alpha-2 agonist used as a sedative, analgesic and centrally acting muscle relaxant in veterinary medicine.

Table of Drugs and ChemicalsClinical

Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.

SubstanceAccidentalSelf-harmAssaultUndeter­minedAdverse
Effect		Under­dosing
XylazineT65.841T65.842T65.843T65.844––

Code History & ChangesHistory

New Code T65.843A was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

Replacement T65.843A replaces the following previously assigned code(s):

  • T65.893A - Toxic effect of oth substances, assault, init encntr
FY 2026AddedAdded to the ICD-10-CM code setEffective October 1, 2025.
FY 2026CurrentRevised in the current code setEffective October 1, 2025 through September 30, 2026.

Questions About T65.843AOverview

Is T65.843A (Toxic effect of xylazine, assault) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report toxic effect of xylazine, assault, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T65.843A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for toxic effect of xylazine, assault, such as an emergency visit or first evaluation.

What MS-DRG does T65.843A group to?

When toxic effect of xylazine, assault, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 917, 918, with relative weights from 0.8571 to 1.5684 depending on complications. Higher weights mean higher Medicare reimbursement.