ICD-10-CM 2027 diagnosis code
W55.11XSBitten by horse, sequela
W55.11XS is a valid, billable ICD-10-CM code for bitten by horse, sequela. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
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 W55.11XS
W55.11XS is the ICD-10-CM diagnosis code for Bitten by horse, sequela. It belongs to category W55 (contact with other mammals), block W50-W64 (exposure to animate mechanical forces) and chapter 20 (external causes of morbidity). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
The 7th character "S" means sequela: use it for complications or conditions that arise as a direct result of the original condition.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as E929.5 (late effects of accident due to natural and environmental factors).
7th character
Ssequela
Other encounter types for W55.11:
Notes that apply from higher levels
Instructions written at a parent level also apply to W55.11XS.
Broader instructions also apply from W50-W64 Exposure to animate mechanical forces and Chapter 20: External causes of morbidity.
ICD-9-CM equivalent
Converter →- E929.5Late effects of accident due to natural and environmental factorsapproximate
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
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 W55.11XS
Is W55.11XS billable?
- Yes. W55.11XS is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
What does the "S" at the end of W55.11XS mean?
- It is the 7th character for sequela. Per the official guidelines, use it for complications or conditions that arise as a direct result of the original condition.
Can W55.11XS be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict W55.11XS as a principal diagnosis.
Is W55.11XS a CC or MCC?
- No. W55.11XS is neither a CC nor an MCC under MS-DRG v44.0.
What is the ICD-9 code for W55.11XS?
- The CMS General Equivalence Mappings map W55.11XS to ICD-9-CM E929.5.