2026 ICD-10-CM Diagnosis Code S96.121ALaceration of muscle and tendon of long extensor muscle of toe at ankle and foot level, right foot, initial encounter

ICD-10-CM Codes›S00–T88›S90-S99›S96

ICD-10-CM S96.121A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S96.121A is a billable ICD-10-CM diagnosis code for laceration of muscle and tendon of long extensor muscle of toe at ankle and foot level, right foot, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 564 through 566, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Open wounds to limbs, initial encounter.

Code Identity

ICD-10-CM Code
S96.121A
Billable Status
Yes — Valid for Submission
Code Describes
Laceration of muscle and tendon of long extensor muscle of toe at ankle and foot level, right foot, initial encounter
Short Description
Lacerat msl/tnd lng extn msl toe at ank/ft lev, r foot, init
Parent Code
S96.121
Laceration of muscle and tendon of long extensor muscle of toe at ankle and foot level, right foot

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS90-S99Injuries to the ankle and foot
CategoryS96Injury of muscle and tendon at ankle and foot level
This CodeS96.121ALaceration of muscle and tendon of long extensor muscle of toe at ankle and foot level, right foot, initial encounter

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Injury of muscle and tendon at ankle and foot level (S96). 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 INJ012
Open wounds to limbs, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Foot Injuries and Disorders

Each of your feet has 26 bones, 33 joints, and more than 100 tendons, muscles, and ligaments. No wonder a lot of things can go wrong. Here are a few common problems:

Read the full article at MedlinePlus

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

Convert S96.121A to ICD-9-CMHistory

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

ICD-9-CM
891.2 Opn wnd knee/leg w tendn
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 S96.121AOverview

Is S96.121A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report laceration of muscle and tendon of long extensor muscle of toe at ankle and foot level, right foot, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S96.121A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for laceration of muscle and tendon of long extensor muscle of toe at ankle and foot level, right foot, such as an emergency visit or first evaluation.

What MS-DRG does S96.121A group to?

When laceration of muscle and tendon of long extensor muscle of toe at ankle and foot level, right foot, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, 963, 964, 965, with relative weights from 0.7493 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S96.121A?

Under the General Equivalence Mappings, laceration of muscle and tendon of long extensor muscle of toe at ankle and foot level, right foot, initial encounter converts to ICD-9-CM 891.2 (opn wnd knee/leg w tendn). 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.