2026 ICD-10-CM Diagnosis Code T65.844SToxic effect of xylazine, undetermined, sequela

ICD-10-CM Codes›S00–T88›T51-T65›T65

ICD-10-CM T65.844S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T65.844S is a billable ICD-10-CM diagnosis code for toxic effect of xylazine, undetermined, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting.

Code Identity

ICD-10-CM Code
T65.844S
Billable Status
Yes — Valid for Submission
Code Describes
Toxic effect of xylazine, undetermined, sequela
Short Description
Toxic effect of xylazine, undetermined, sequela
Same as the full description in the CMS dataset.
Parent Code
T65.844
Toxic effect of xylazine, undetermined

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 CodeT65.844SToxic effect of xylazine, undetermined, sequela

Present on Admission (POA)Billing

T65.844S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

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 T65.844S was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

Replacement T65.844S replaces the following previously assigned code(s):

  • T65.894S - Toxic effect of oth substances, undetermined, sequela
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 T65.844SOverview

Is T65.844S (Toxic effect of xylazine, undetermined) a billable code?

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

What does the 7th character S in T65.844S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the toxic effect of xylazine, undetermined itself has resolved, not the original event.

What MS-DRG does T65.844S group to?

When toxic effect of xylazine, undetermined, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T65.844S exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for toxic effect of xylazine, undetermined, sequela on inpatient claims.