2026 ICD-10-CM Diagnosis Code S24.3XXAInjury of peripheral nerves of thorax, initial encounter
S24.3XXA is a billable ICD-10-CM diagnosis code for injury of peripheral nerves of thorax, 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. Coders also document this condition as injury of cutaneous sensory nerve of upper limb. 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.
- Injury of cutaneous sensory nerve of upper limb
- Injury of intercostobrachial nerve
- Injury of peripheral nerve of thorax
- Long thoracic nerve injury
- Long thoracic nerve lesion
- Open injury, long thoracic nerve
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of nerves and spinal cord at thorax level (S24). 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
Peripheral Nerve Disorders
Nerves are like wires that carry messages back and forth between your brain and your body. Your peripheral nerves branch off from your brain and spinal cord and connect to all parts of your body, including your muscles and organs.
The full article covers:
- What are peripheral nerves?
- What are peripheral nerve disorders?
- What causes peripheral nerve disorders?
- What are the symptoms of peripheral nerve disorders?
- How are peripheral nerve disorders diagnosed?
- What are the treatments for peripheral nerve disorders?
- Can peripheral nerve disorders be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S24.3XXA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S24.3XXAOverview
Is S24.3XXA (Injury of peripheral nerves of thorax) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report injury of peripheral nerves of thorax, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S24.3XXA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for injury of peripheral nerves of thorax, such as an emergency visit or first evaluation.
What MS-DRG does S24.3XXA group to?
When injury of peripheral nerves of thorax, 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 S24.3XXA?
Under the General Equivalence Mappings, injury of peripheral nerves of thorax, initial encounter converts to ICD-9-CM 954.8 (injury trunk nerve NEC). 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.
