2026 ICD-10-CM Diagnosis Code S84.10XAInjury of peroneal nerve at lower leg level, unspecified leg, initial encounter
S84.10XA is a billable ICD-10-CM diagnosis code for injury of peroneal nerve at lower leg level, unspecified leg, 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 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury to nerves, muscles and tendons, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Closed injury common peroneal nerve
- Closed injury deep peroneal nerve
- Closed injury superficial peroneal nerve
- Deep peroneal nerve lesion
- Open injury common peroneal nerve
- Open injury deep peroneal nerve
- Open injury superficial peroneal nerve
- Peroneal nerve injury
- Superficial peroneal neuropathy
- Traumatic injury of common peroneal nerve
- Traumatic injury of deep peroneal nerve
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of nerves at lower leg level (S84). 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.
Patient EducationClinical
Leg Injuries and Disorders
Your legs are made up of bones, blood vessels, muscles, and other connective tissue. They are important for motion and standing. Playing sports, running, falling, or having an accident can damage your legs. Common leg injuries include sprains and strains, joint dislocations, and fractures (broken bones).
Read the full article at MedlinePlus
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Convert S84.10XA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S84.10XAOverview
Is S84.10XA (Injury of peroneal nerve at lower leg level, unspecified leg) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report injury of peroneal nerve at lower leg level, unspecified leg, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S84.10XA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for injury of peroneal nerve at lower leg level, unspecified leg, such as an emergency visit or first evaluation.
What MS-DRG does S84.10XA group to?
When injury of peroneal nerve at lower leg level, unspecified leg, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 963, 964, 965, with relative weights from 0.9405 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S84.10XA?
Under the General Equivalence Mappings, injury of peroneal nerve at lower leg level, unspecified leg, initial encounter converts to ICD-9-CM 956.3 (injury peroneal nerve). 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.
