2027 ICD-10-CM Diagnosis Code S24.4XXAInjury of thoracic sympathetic nervous system, initial encounter

ICD-10-CM Codes›S00–T88›S20-S29›S24

ICD-10-CM S24.4XXA
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S24.4XXA is a billable ICD-10-CM diagnosis code for injury of thoracic sympathetic nervous system, 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 73 through 74, 963 through 965. Coders also document this condition as injury of ganglion of nervous system. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury to nerves, muscles and tendons, initial encounter.

Code Identity

ICD-10-CM Code
S24.4XXA
Billable Status
Yes — Valid for Submission
Code Describes
Injury of thoracic sympathetic nervous system, initial encounter
Short Description
Injury of thoracic sympathetic nervous system, init encntr
Parent Code
S24.4
Injury of thoracic sympathetic nervous system

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS20-S29Injuries to the thorax
CategoryS24Injury of nerves and spinal cord at thorax level
This CodeS24.4XXAInjury of thoracic sympathetic nervous system, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Injury of ganglion of nervous system
  • Injury of stellate ganglion
  • Injury of thoracic sympathetic nerves

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 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 S24.4XXA: its own notes plus those printed at S24, block S20-S29, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block S20-S29 Injuries to the thorax applies to 1,602 codes
  • injuries of breast
  • injuries of chest (wall)
  • injuries of interscapular area

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.

From S24 Injury of nerves and spinal cord at thorax level applies to 93 codes
  • injury of brachial plexus (S14.3)
From Block S20-S29 Injuries to the thorax applies to 1,602 codes
  • burns and corrosions (T20-T32)
  • effects of foreign body in bronchus (T17.5)
  • effects of foreign body in esophagus (T18.1)
  • effects of foreign body in lung (T17.8)
  • effects of foreign body in trachea (T17.4)
  • frostbite (T33-T34)
  • injuries of axilla
  • injuries of clavicle
  • injuries of scapular region
  • injuries of shoulder
  • 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.

From S24 Injury of nerves and spinal cord at thorax level applies to 93 codes
  • any associated:
  • fracture of thoracic vertebra (S22.0-)
  • open wound of thorax (S21.-)
  • transient paralysis (R29.5)

Notes

General instructions on how these codes are used.

From S24 Injury of nerves and spinal cord at thorax level applies to 93 codes
  • Code to highest level of thoracic spinal cord injury
  • Injuries to the spinal cord (S24.0 and S24.1) refer to the cord level and not bone level injury, and can affect nerve roots at and below the level given.
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.

From S24 Injury of nerves and spinal cord at thorax level applies to 93 codes
  • The appropriate 7th character is to be added to each code from category S24
Values for category S24 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter this code
  • 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 S24.4XXA, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming S24.4XXA: they are not reported together with it, unless the two conditions are unrelated.

  • G83.8 Other specified paralytic syndromes
    paralytic syndromes due to current spinal cord injury-code to spinal cord injury (S14, S24, S34) names S24, which includes this code

Clinical ClassificationClinical

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

CCSR INJ025
Injury to nerves, muscles and tendons, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

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 S24.4XXA to ICD-9-CMHistory

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

ICD-9-CM
954.1 Inj sympath nerve NEC
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S24.4XXAOverview

What is the ICD-10 code for injury of thoracic sympathetic nervous system, initial encounter?

The ICD-10-CM code for injury of thoracic sympathetic nervous system, initial encounter is S24.4XXA (sometimes written as S244XXA). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is S24.4XXA (Injury of thoracic sympathetic nervous system) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report injury of thoracic sympathetic nervous system, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in S24.4XXA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for injury of thoracic sympathetic nervous system, such as an emergency visit or first evaluation.

What MS-DRG does S24.4XXA group to?

When injury of thoracic sympathetic nervous system, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 964, 965, 74, 73, 963, with relative weights from 1.0054 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S24.4XXA?

Under the General Equivalence Mappings, injury of thoracic sympathetic nervous system, initial encounter converts to ICD-9-CM 954.1 (inj sympath nerve NEC). The mapping is approximate, so confirm the match fits the documentation.