2026 ICD-10-CM Diagnosis Code T63.891AToxic effect of contact with other venomous animals, accidental (unintentional), initial encounter

ICD-10-CM Codes›S00–T88›T51-T65›T63

ICD-10-CM T63.891A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T63.891A is a billable ICD-10-CM diagnosis code for toxic effect of contact with other venomous animals, accidental (unintentional), 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. Coders also document this condition as poisoning due to sting of duckbill platypus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: bites; initial encounter; External cause codes: intent of injury, accidental/unintentional; and Toxic effects, initial encounter.

Code Identity

ICD-10-CM Code
T63.891A
Billable Status
Yes — Valid for Submission
Code Describes
Toxic effect of contact with other venomous animals, accidental (unintentional), initial encounter
Short Description
Toxic effect of contact w oth venomous animals, acc, init
Parent Code
T63.891
Toxic effect of contact with other venomous animals, accidental (unintentional)

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT51-T65Toxic effects of substances chiefly nonmedicinal as to source
CategoryT63Toxic effect of contact with venomous animals and plants
This CodeT63.891AToxic effect of contact with other venomous animals, accidental (unintentional), initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Poisoning due to sting of duckbill platypus

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Toxic effect of contact with venomous animals and plants (T63). 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 ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR EXT012
External cause codes: bites; initial encounter
Default principal diagnosis: inpatient No · outpatient No
CCSR EXT020
External cause codes: intent of injury, accidental/unintentional
Default principal diagnosis: inpatient No · outpatient No
CCSR INJ023
Toxic effects, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Poisoning

A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be poisonous if too much is taken. Poisons can include:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T63.891A to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
989.5 Toxic effect venom
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
E905.6 Venom sea animals/plants
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T63.891AOverview

Is T63.891A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report toxic effect of contact with other venomous animals, accidental (unintentional), initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T63.891A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for toxic effect of contact with other venomous animals, accidental (unintentional), such as an emergency visit or first evaluation.

What MS-DRG does T63.891A group to?

When toxic effect of contact with other venomous animals, accidental (unintentional), 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.

What is the ICD-9 equivalent of T63.891A?

Under the General Equivalence Mappings, toxic effect of contact with other venomous animals, accidental (unintentional), initial encounter converts to ICD-9-CM 989.5 (toxic effect venom) and E905.6 (venom sea animals/plants). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.