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ICD-10/W55.21XA

W55.21XA ICD-10-CM Code: Bitten by cow, initial encounter

W55.21XA is the authoritative medical code for Bitten by cow, initial encounter. This classification is used in medical billing and clinical recording to specify the clinical criteria for bitten by cow, initial encounter (ICD-10-CM W55.21XA), ensuring healthcare documentation aligns with current federal coding standards.

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

Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.

Official Registry Overview & Definition

Bitten by cow, initial encounter is a billable ICD-10-CM diagnosis code (W55.21A). Includes: contact with saliva, feces or urine of mammal. Excludes1 (not coded here): animal being ridden- see transport accidents; bitten or struck by dog (W54); bitten or struck by rodent (W53.-); contact with marine mammals (W56.-); Toxic effect of contact with venomous animals and plants (T63.-). 7th character: The appropriate 7th character is to be added to each code from category W55.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for W55.21XA in the official ICD-10-CM tabular list.

Includes

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

  • contact with saliva, feces or urine of mammal

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • animal being ridden- see transport accidents
  • bitten or struck by dog (W54)
  • bitten or struck by rodent (W53.-)
  • contact with marine mammals (W56.-)
  • Toxic effect of contact with venomous animals and plants (T63.-)

Frequently Asked Questions (FAQ) & Clinical Guidance

Does W55.21XA require a 7th character?

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

What can't be coded together with W55.21XA?

Per official ICD-10-CM Excludes1 instructions, W55.21XA must not be reported together with: animal being ridden- see transport accidents; bitten or struck by dog (W54); bitten or struck by rodent (W53.-); contact with marine mammals (W56.-).

Nearest Codes in This Family

Official ICD-10-CM classifications closest to W55.21XA in its code family, with their registry titles.

  • W55.19XA — Other contact with horse, initial encounter
  • W55.19XD — Other contact with horse, subsequent encounter
  • W55.19XS — Other contact with horse, sequela
  • W55.2 — Contact with cow
  • W55.21 — Bitten by cow
  • W55.21XD — Bitten by cow, subsequent encounter
  • W55.21XS — Bitten by cow, sequela
  • W55.22 — Struck by cow
  • W55.22XA — Struck by cow, initial encounter
  • W55.22XD — Struck by cow, subsequent encounter

View all codes in the W55 family