2026 ICD-10-CM Diagnosis Code S23.101ADislocation of unspecified thoracic vertebra, initial encounter

ICD-10-CM CodesS00–T88S20-S29S23

ICD-10-CM S23.101A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S23.101A is a billable ICD-10-CM diagnosis code for dislocation of unspecified thoracic vertebra, 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
S23.101A
Billable Status
Yes — Valid for Submission
Code Describes
Dislocation of unspecified thoracic vertebra, initial encounter
Short Description
Dislocation of unspecified thoracic vertebra, init encntr
Parent Code
Dislocation of unspecified thoracic vertebra

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 CodeS23.101ADislocation of unspecified thoracic vertebra, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Anterior lesion of thoracic spinal cord due to closed dislocation of joint of thoracic spine
  • Anterior lesion of thoracic spinal cord due to open dislocation of joint of thoracic spine
  • Central cord syndrome of thoracic spinal cord due to closed dislocation of joint of thoracic spine
  • Central cord syndrome of thoracic spinal cord due to open dislocation of joint of thoracic spine
  • Central cord syndrome of thoracic spinal cord due to traumatic injury
  • Closed dislocation of thoracic and lumbar spine
  • Closed dislocation thoracic spine
  • Closed spinal dislocation with complete thoracic cord lesion
  • Closed traumatic dislocation of lumbar vertebra
  • Closed traumatic dislocation of thoracic vertebra
  • Dislocation of costovertebral joint
  • Dislocation of thoracic facet joint
  • Fracture dislocation of spine
  • Fracture dislocation of thoracic spine
  • Lesion of thoracic spinal cord due to closed dislocation of joint of thoracic spine
  • Lesion of thoracic spinal cord due to open dislocation of joint of thoracic spine
  • Open dislocation thoracic spine
  • Open spinal dislocation with complete thoracic cord lesion
  • Open traumatic dislocation costovertebral joint
  • Posterior cord syndrome of thoracic spinal cord due to closed dislocation of joint of thoracic spine
  • Posterior cord syndrome of thoracic spinal cord due to open dislocation of joint of thoracic spine
  • Thoracic spinal cord lesion due to thoracic spinal dislocation
  • Traumatic dislocation of joint of thoracic vertebra
  • Traumatic injury of thoracic and lumbar vertebral column regions

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

Dislocations

Dislocations are joint injuries that force the ends of your bones out of position. The cause is often a fall or a blow, sometimes from playing a contact sport. You can dislocate your ankles, knees, shoulders, hips, elbows and jaw. You can also dislocate your finger and toe joints.

Read the full article at MedlinePlus

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

Convert S23.101A to ICD-9-CMHistory

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

ICD-9-CM
839.21 Disloc thoracic vert-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 S23.101AOverview

Is S23.101A (Dislocation of unspecified thoracic vertebra) a billable code?

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

What does the 7th character A in S23.101A mean?

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

What MS-DRG does S23.101A group to?

When dislocation of unspecified thoracic vertebra, 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 S23.101A?

Under the General Equivalence Mappings, dislocation of unspecified thoracic vertebra, initial encounter converts to ICD-9-CM 839.21 (disloc thoracic vert-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.