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ICD-10-CM 2027 diagnosis code

S91.00Unspecified open wound of ankle

Not billable — use a more specific codeRequires 7th character

S91.00 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it and add the required 7th character.

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 S91.00

S91.00 is the ICD-10-CM diagnosis code for unspecified open wound of ankle. It belongs to category S91 (open wound of ankle, foot and toes), block S90-S99 (injuries to the ankle and foot) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within S91.0, choose S91.00 (Unspecified open wound of ankle) only when documentation doesn't support a more specific option: laceration without foreign body of ankle (S91.01), laceration with foreign body of ankle (S91.02), puncture wound without foreign body of ankle (S91.03), puncture wound with foreign body of ankle (S91.04) and open bite of ankle (S91.05).

Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.

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

7th character

The appropriate 7th character is to be added to each code from category S91

  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela

Notes that apply from higher levels

Instructions written at a parent level also apply to S91.00.

› From S91 Open wound of ankle, foot and toes
Excludes1
  • open fracture of ankle, foot and toes (S92.-with 7th character B)
  • traumatic amputation of ankle and foot (S98.-)
Code also
  • any associated wound infection

Broader instructions also apply from S90-S99 Injuries to the ankle and foot and Chapter 19: Injury, poisoning and certain other consequences of external causes.

Alphabetic index entries

1 entries

Terms in the official ICD-10-CM index that lead to S91.00.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about S91.00

Is S91.00 billable?

No. S91.00 is a header code. Report one of its more specific subcodes instead.