2026 ICD-10-CM Diagnosis Code S23.29XADislocation of other parts of thorax, initial encounter

ICD-10-CM Codes›S00–T88›S20-S29›S23

ICD-10-CM S23.29XA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S23.29XA is a billable ICD-10-CM diagnosis code for dislocation of other parts 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 551 through 552, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Dislocations, initial encounter.

Code Identity

ICD-10-CM Code
S23.29XA
Billable Status
Yes — Valid for Submission
Code Describes
Dislocation of other parts of thorax, initial encounter
Short Description
Dislocation of other parts of thorax, initial encounter
Same as the full description in the CMS dataset.
Parent Code
S23.29
Dislocation of other parts of thorax

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS20-S29Injuries to the thorax
CategoryS23Dislocation and sprain of joints and ligaments of thorax
This CodeS23.29XADislocation of other parts of thorax, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Closed fracture dislocation of sternum
  • Closed fracture of sternum
  • Closed traumatic dislocation costovertebral joint
  • Closed traumatic dislocation of costochondral joint
  • Closed traumatic dislocation of sternum
  • Closed traumatic subluxation costovertebral joint
  • Closed traumatic subluxation of costochondral joint
  • Closed traumatic subluxation of sternum
  • Dislocation of costal cartilage
  • Dislocation of costovertebral joint
  • Dislocation of scapulothoracic joint
  • Dislocation of sternocostal joint
  • Open fracture dislocation of sternum
  • Open fracture of sternum
  • Open fracture subluxation of sternum
  • Open traumatic dislocation costovertebral joint
  • Open traumatic dislocation of costochondral joint
  • Open traumatic dislocation of sternum
  • Open traumatic subluxation costovertebral joint
  • Open traumatic subluxation of costochondral joint
  • Open traumatic subluxation of sternum
  • Subluxation of costochondral joint
  • Subluxation of costovertebral joint
  • Subluxation of scapulothoracic joint
  • Subluxation of sternocostal joint
  • Traumatic dislocation of sternum

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments of thorax (S23). 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 INJ007
Dislocations, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Chest Injuries and Disorders

The chest is the part of your body between your neck and your abdomen (belly). The medical term for your chest is thorax.

The full article covers:

  • What is the chest?
  • What are chest injuries and disorders?
  • How are chest injuries and disorders diagnosed?

Read the full article at MedlinePlus

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

Convert S23.29XA to ICD-9-CMHistory

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

ICD-9-CM
839.40 Dislocat vertebra NOS-cl
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 S23.29XAOverview

Is S23.29XA (Dislocation of other parts of thorax) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report dislocation of other parts of thorax, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S23.29XA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for dislocation of other parts of thorax, such as an emergency visit or first evaluation.

What MS-DRG does S23.29XA group to?

When dislocation of other parts of thorax, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 551, 552, 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 S23.29XA?

Under the General Equivalence Mappings, dislocation of other parts of thorax, initial encounter converts to ICD-9-CM 839.40 (dislocat vertebra NOS-cl). 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.