2027 ICD-10-CM Diagnosis Code S81Open wound of knee and lower leg

ICD-10-CM Codes›S00–T88›S80-S89›S81

ICD-10-CM S81
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S81 is a non-billable ICD-10-CM category code for open wound of knee and lower leg, so it cannot be submitted on claims. Use a more specific code from this category instead, such as S81.001A, S81.001D, S81.001S, and S81.002A.

Code Identity

ICD-10-CM Code
S81
Billable Status
No — Non-Billable Category
Code Describes
Open wound of knee and lower leg
Short Description
Open wound of knee and lower leg
Same as the full description in the CMS dataset.
Chapter
S80-S89
Injuries to the knee and lower leg

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS80-S89Injuries to the knee and lower leg
CategoryS81Open wound of knee and lower leg
This CodeS81Open wound of knee and lower leg

Specific Coding for Open wound of knee and lower legOverview

Non-specific codes like S81 require more characters. Use one of these billable codes instead:

  • S81.0 for Open wound of knee

  • S81.00 for Unspecified open wound of knee

  • S81.01 for Laceration without foreign body of knee

  • S81.02 for Laceration with foreign body of knee

  • S81.03 for Puncture wound without foreign body of knee

  • S81.04 for Puncture wound with foreign body of knee

  • S81.05 for Open bite of knee

  • S81.8 for Open wound of lower leg

  • S81.80 for Unspecified open wound of lower leg

  • S81.81 for Laceration without foreign body of lower leg

  • S81.82 for Laceration with foreign body of lower leg

  • S81.83 for Puncture wound without foreign body of lower leg

  • S81.84 for Puncture wound with foreign body of lower leg

  • S81.85 for Open bite of lower leg

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Open wound of knee and lower leg (S81). 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 S81: its own notes plus those printed at block S80-S89 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 knee and lower leg (S82.-)
  • traumatic amputation of lower leg (S88.-)

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.

On S81 itself
  • open wound of ankle and foot (S91.-)
From Block S80-S89 Injuries to the knee and lower leg applies to 4,680 codes
  • burns and corrosions (T20-T32)
  • frostbite (T33-T34)
  • injuries of ankle and foot, except fracture of ankle and malleolus (S90-S99)
  • 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 S81
Values for category S81 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 S81, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming S81: 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 knee and lower leg (S81.-)

Code Also 3

These codes say S81 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • S84 Injury of nerves at lower leg level
    any associated open wound (S81.-)
  • S85 Injury of blood vessels at lower leg level
    any associated open wound (S81.-)
  • S86 Injury of muscle, fascia and tendon at lower leg level
    any associated open wound (S81.-)

Patient EducationClinical

Knee Injuries and Disorders

Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty walking.

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 S81Overview

What is the ICD-10 code for open wound of knee and lower leg?

S81 is the ICD-10-CM category for open wound of knee and lower leg, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is S81 (Open wound of knee and lower leg) a billable code?

No. This is a category header that groups the codes for open wound of knee and lower leg, and headers cannot be submitted on claims. Claims for open wound of knee and lower leg need a more specific code from this category, such as S81.001A, S81.001D, and S81.001S.

Can S81 be reported with a code from S82?

Not as a rule. The Excludes1 note on S81 lists "open fracture of knee and lower leg (S82.-)". 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).