Skip to main content

W55.31XA ICD-10-CM Code: Bitten by other hoof stock, initial encounter

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

Coding at a Glance

7th character
Required — see the character table on this page
Tabular directives
1 inclusion term · 5 Excludes1

Code Overview

Bitten by other hoof stock, initial encounter is a billable ICD-10-CM diagnosis code (W55.31XA).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for W55.31XA in the official ICD-10-CM tabular list.

Notes without a marker are published on W55.31XA itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • contact with saliva, feces or urine of mammal

Source: inherited from W55

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).

7th Character Guide

"The appropriate 7th character is to be added to each code from category W55"

  • A — initial encounter (this page’s code)
  • D — subsequent encounter
  • S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

W55.31XA, W55.31XD, W55.31XS

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Bitten by other hoof stock, initial encounter

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Verify Before Coding

  • Principal-diagnosis restriction. External cause of morbidity codes (V, W, X and Y) describe the circumstance that caused an injury, not the condition treated. The Medicare Code Editor rejects them as a principal diagnosis; sequence the injury or condition first and report this code as secondary.

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

Relationships & Classification

Clinical classification (AHRQ CCSR):EXT012 — External cause codes: bites; initial encounter; EXT020 — External cause codes: intent of injury, accidental/unintentional.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (External cause codes: bites; initial encounter, External cause codes: intent of injury, accidental/unintentional).

T63.93XA — Toxic effect of contact with unspecified venomous animal, assault, initial encounter, T63.94XA — Toxic effect of contact with unspecified venomous animal, undetermined, initial encounter, W53.01XA — Bitten by mouse, initial encounter, W53.11XA — Bitten by rat, initial encounter, W53.21XA — Bitten by squirrel, initial encounter, W53.81XA — Bitten by other rodent, initial encounter, W54.0XXA — Bitten by dog, initial encounter, W55.01XA — Bitten by cat, initial encounter, W55.11XA — Bitten by horse, initial encounter, W55.21XA — Bitten by cow, initial encounter, W55.41XA — Bitten by pig, initial encounter, W55.51XA — Bitten by raccoon, initial encounter, W55.81XA — Bitten by other mammals, initial encounter, W56.01XA — Bitten by dolphin, initial encounter, W56.11XA — Bitten by sea lion, initial encounter, W56.21XA — Bitten by orca, initial encounter, W56.31XA — Bitten by other marine mammals, initial encounter, W56.41XA — Bitten by shark, initial encounter, W56.51XA — Bitten by other fish, initial encounter, W56.81XA — Bitten by other nonvenomous marine animals, initial encounter, +2395 more

Contextual Map

Every relationship of W55.31XA 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

Clinical classification (CCSR)

Nearest codes (40)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]

Frequently Asked Questions (FAQ) & Clinical Guidance

Does W55.31XA require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category W55.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to W55.31XA in its code family, with their registry titles.

View all codes in the W55 family