2026 ICD-10-CM Diagnosis Code S81.002SUnspecified open wound, left knee, sequela

ICD-10-CM CodesS00–T88S80-S89S81

ICD-10-CM S81.002S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S81.002S is a billable ICD-10-CM diagnosis code for unspecified open wound, left knee, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 604 through 605. The code is exempt from POA reporting. Coders also document this condition as disorder of left patella. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.

Code Identity

ICD-10-CM Code
S81.002S
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified open wound, left knee, sequela
Short Description
Unspecified open wound, left knee, sequela
Same as the full description in the CMS dataset.
Parent Code
Unspecified open wound, left knee

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 CodeS81.002SUnspecified open wound, left knee, sequela

Present on Admission (POA)Billing

S81.002S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Disorder of left patella
  • Fracture of left patella
  • Open dislocation of patella
  • Open fracture of left patella
  • Open fracture of patella
  • Open traumatic dislocation of left knee joint
  • Open traumatic dislocation of left patella
  • Open wound of left knee

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 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ073
Injury, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

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.

Convert S81.002S to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
906.1 Late eff open wnd extrem
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S81.002SOverview

Is S81.002S (Unspecified open wound, left knee) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified open wound, left knee, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in S81.002S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the unspecified open wound, left knee itself has resolved, not the original event.

What MS-DRG does S81.002S group to?

When unspecified open wound, left knee, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, with relative weights from 0.9160 to 1.4721 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S81.002S exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for unspecified open wound, left knee, sequela on inpatient claims.

What is the ICD-9 equivalent of S81.002S?

Under the General Equivalence Mappings, unspecified open wound, left knee, sequela converts to ICD-9-CM 906.1 (late eff open wnd extrem). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.