2026 ICD-10-CM Diagnosis Code S23.9XXSSprain of unspecified parts of thorax, sequela

ICD-10-CM CodesS00–T88S20-S29S23

ICD-10-CM S23.9XXS
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S23.9XXS is a billable ICD-10-CM diagnosis code for sprain of unspecified parts of thorax, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 562 through 563. The code is exempt from POA reporting. Coders also document this condition as dislocations, sprains and strains involving multiple body regions. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.

Code Identity

ICD-10-CM Code
S23.9XXS
Billable Status
Yes — Valid for Submission
Code Describes
Sprain of unspecified parts of thorax, sequela
Short Description
Sprain of unspecified parts of thorax, sequela
Same as the full description in the CMS dataset.
Parent Code
Sprain of unspecified 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 CodeS23.9XXSSprain of unspecified parts of thorax, sequela

Present on Admission (POA)Billing

S23.9XXS is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Dislocations, sprains and strains involving multiple body regions
  • Dislocations, sprains and strains involving thorax with lower back and pelvis
  • Dislocations/sprains/strains

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 INJ073
Injury, sequela
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 S23.9XXS to ICD-9-CMHistory

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

ICD-9-CM
905.7 Late effec sprain/strain
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 S23.9XXSOverview

Is S23.9XXS (Sprain of unspecified parts of thorax) a billable code?

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

What does the 7th character S in S23.9XXS mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the sprain of unspecified parts of thorax itself has resolved, not the original event.

What MS-DRG does S23.9XXS group to?

When sprain of unspecified parts of thorax, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 562, 563, with relative weights from 0.8955 to 1.4248 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S23.9XXS exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for sprain of unspecified parts of thorax, sequela on inpatient claims.

What is the ICD-9 equivalent of S23.9XXS?

Under the General Equivalence Mappings, sprain of unspecified parts of thorax, sequela converts to ICD-9-CM 905.7 (late effec sprain/strain). 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.