2027 ICD-10-CM Diagnosis Code S91Open wound of ankle, foot and toes

ICD-10-CM Codes›S00–T88›S90-S99›S91

ICD-10-CM S91
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S91 is a non-billable ICD-10-CM category code for open wound of ankle, foot and toes, so it cannot be submitted on claims. Use a more specific code from this category instead, such as S91.001A, S91.001D, S91.001S, and S91.002A.

Code Identity

ICD-10-CM Code
S91
Billable Status
No — Non-Billable Category
Code Describes
Open wound of ankle, foot and toes
Short Description
Open wound of ankle, foot and toes
Same as the full description in the CMS dataset.
Chapter
S90-S99
Injuries to the ankle and foot

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS90-S99Injuries to the ankle and foot
CategoryS91Open wound of ankle, foot and toes
This CodeS91Open wound of ankle, foot and toes

Specific Coding for Open wound of ankle, foot and toesOverview

Non-specific codes like S91 require more characters. Use one of these billable codes instead:

  • S91.0 for Open wound of ankle

  • S91.00 for Unspecified open wound of ankle

  • S91.01 for Laceration without foreign body of ankle

  • S91.02 for Laceration with foreign body of ankle

  • S91.03 for Puncture wound without foreign body of ankle

  • S91.04 for Puncture wound with foreign body of ankle

  • S91.05 for Open bite of ankle

  • S91.1 for Open wound of toe without damage to nail

  • S91.10 for Unspecified open wound of toe without damage to nail

  • S91.11 for Laceration without foreign body of toe without damage to nail

  • S91.12 for Laceration with foreign body of toe without damage to nail

  • S91.13 for Puncture wound without foreign body of toe without damage to nail

  • S91.14 for Puncture wound with foreign body of toe without damage to nail

  • S91.15 for Open bite of toe without damage to nail

  • S91.2 for Open wound of toe with damage to nail

  • S91.20 for Unspecified open wound of toe with damage to nail

  • S91.21 for Laceration without foreign body of toe with damage to nail

  • S91.22 for Laceration with foreign body of toe with damage to nail

  • S91.23 for Puncture wound without foreign body of toe with damage to nail

  • S91.24 for Puncture wound with foreign body of toe with damage to nail

  • S91.25 for Open bite of toe with damage to nail

  • S91.3 for Open wound of foot

  • S91.30 for Unspecified open wound of foot

  • S91.31 for Laceration without foreign body of foot

  • S91.32 for Laceration with foreign body of foot

  • S91.33 for Puncture wound without foreign body of foot

  • S91.34 for Puncture wound with foreign body of foot

  • S91.35 for Open bite of foot

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Open wound of ankle, foot and toes (S91). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to S91: its own notes plus those printed at block S90-S99 and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • open fracture of ankle, foot and toes (S92.-with 7th character B)
  • traumatic amputation of ankle and foot (S98.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block S90-S99 Injuries to the ankle and foot applies to 3,324 codes
  • burns and corrosions (T20-T32)
  • fracture of ankle and malleolus (S82.-)
  • frostbite (T33-T34)
  • insect bite or sting, venomous (T63.4)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

  • any associated wound infection

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

  • The appropriate 7th character is to be added to each code from category S91
Values for category S91 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name S91, its category, or a range that includes it.

Excludes2 2

These codes carry an Excludes2 note naming S91: its condition is not part of those codes, and both may be reported when the patient has both.

  • S71 Open wound of hip and thigh
    open wound of ankle, foot and toes (S91.-)
  • S81 Open wound of knee and lower leg
    open wound of ankle and foot (S91.-)

Code Also 3

These codes say S91 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • S94 Injury of nerves at ankle and foot level
    any associated open wound (S91.-)
  • S95 Injury of blood vessels at ankle and foot level
    any associated open wound (S91.-)
  • S96 Injury of muscle and tendon at ankle and foot level
    any associated open wound (S91.-)

Patient EducationClinical

Ankle Injuries and Disorders

Your ankle bone and the ends of your two lower leg bones make up the ankle joint. Your ligaments, which connect bones to one another, stabilize and support it. Your muscles and tendons move it.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S91Overview

What is the ICD-10 code for open wound of ankle, foot and toes?

S91 is the ICD-10-CM category for open wound of ankle, foot and toes, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is S91 (Open wound of ankle, foot and toes) a billable code?

No. This is a category header that groups the codes for open wound of ankle, foot and toes, and headers cannot be submitted on claims. Claims for open wound of ankle, foot and toes need a more specific code from this category, such as S91.001A, S91.001D, and S91.001S.

Can S91 be reported with S92?

Not as a rule. The Excludes1 note on S91 lists "open fracture of ankle, foot and toes (S92.-with 7th character B)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).