2027 ICD-10-CM Diagnosis Code S29.9XXAUnspecified injury of thorax, initial encounter
S29.9XXA is a billable ICD-10-CM diagnosis code for unspecified injury 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 913 through 914, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other unspecified injury.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Blunt injury
- Blunt injury of thorax
- Breast hematoma
- Central cord syndrome of thoracic spinal cord due to traumatic injury
- Chest injury
- Clavicle injury
- Costal cartilage injury
- Deceleration injury of thorax
- Injury of back of chest
- Injury of breast
- Injury of chest wall
- Injury of front of chest
- Injury of interscapular region
- Injury of left breast
- Injury of ribs
- Injury of right breast
- Injury of side of chest
- Injury of sternum
- Injury of thoracic cavity
- Internal injury of chest, abdomen and pelvis
- Multiple injuries of head and chest
- Multiple injuries of thorax
- Traumatic hematoma of breast
- Traumatic injury of chest wall
- Traumatic injury of posterior chest wall
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Other and unspecified injuries of thorax (S29). 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 S29.9XXA: its own notes plus those printed at S29, 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.
- 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.
- 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)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- 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.
Notes
General instructions on how these codes are used.
- 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.
- The appropriate 7th character is to be added to each code from category S29
- Ainitial encounter this code
- Dsubsequent encounter
- Ssequela
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 S29.9XXA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S29.9XXAOverview
What is the ICD-10 code for unspecified injury of thorax, initial encounter?
The ICD-10-CM code for unspecified injury of thorax, initial encounter is S29.9XXA (sometimes written as S299XXA). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is S29.9XXA (Unspecified injury of thorax) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of thorax, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character A in S29.9XXA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified injury of thorax, such as an emergency visit or first evaluation.
What MS-DRG does S29.9XXA group to?
When unspecified injury of thorax, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 964, 965, 914, 913, 963, with relative weights from 0.9281 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S29.9XXA?
Under the General Equivalence Mappings, unspecified injury of thorax, initial encounter converts to ICD-9-CM 959.11 (injury of chest wall NEC). The mapping is approximate, so confirm the match fits the documentation.
