ICD-10-CM 2027 diagnosis code

W55Contact with other mammals

Not billable — use a more specific code

W55 is a header code, so it can't be reported by itself. Choose one of the 7 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About W55

W55 is the ICD-10-CM diagnosis code for contact with other mammals. It belongs to block W50-W64 (exposure to animate mechanical forces) and chapter 20 (external causes of morbidity). It is a header code, so it can't be reported by itself; one of its 7 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: W55.0 (cat), W55.1 (horse), W55.2 (cow), W55.3 (stock), W55.4 (pig), W55.5 (raccoon) and W55.8 (mammals).

Don't report W55 together with the conditions in its Excludes1 note: animal being ridden- see transport accidents, bitten or struck by dog (W54), bitten or struck by rodent (W53.-) and contact with marine mammals (W56.-).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Coding notes

IncludesFurther defines the content of the category

contact with saliva, feces or urine of mammal

Excludes1Not coded here — never report together with this code

animal being ridden- see transport accidents
bitten or struck by dog (W54)
bitten or struck by rodent (W53.-)
contact with marine mammals (W56.-)

Notes that apply from higher levels

Instructions written at a parent level also apply to W55.

Broader instructions also apply from W50-W64 Exposure to animate mechanical forces and Chapter 20: External causes of morbidity.

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about W55

Is W55 billable?: No. W55 is a header code. Report one of its more specific subcodes instead.