2027 ICD-10-CM Diagnosis Code S29.091AOther injury of muscle and tendon of front wall of thorax, initial encounter

ICD-10-CM Codes›S00–T88›S20-S29›S29

ICD-10-CM S29.091A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S29.091A is a billable ICD-10-CM diagnosis code for other injury of muscle and tendon of front wall 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 Injury to nerves, muscles and tendons, initial encounter.

Code Identity

ICD-10-CM Code
S29.091A
Billable Status
Yes — Valid for Submission
Code Describes
Other injury of muscle and tendon of front wall of thorax, initial encounter
Short Description
Inj muscle and tendon of front wall of thorax, init encntr
Parent Code
S29.091
Other injury of muscle and tendon of front wall of thorax

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS20-S29Injuries to the thorax
CategoryS29Other and unspecified injuries of thorax
This CodeS29.091AOther injury of muscle and tendon of front wall of thorax, initial encounter

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 S29.091A: 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.

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 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 S29 Other and unspecified injuries of thorax applies to 42 codes
  • any associated open wound (S21.-)

Notes

General instructions on how these codes are used.

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 S29 Other and unspecified injuries of thorax applies to 42 codes
  • The appropriate 7th character is to be added to each code from category S29
Values for category S29 Encounter: Initial, Subsequent, Sequela
  • 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.

CCSR INJ025
Injury to nerves, muscles and tendons, 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 S29.091A to ICD-9-CMHistory

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

ICD-9-CM
959.11 Injury of chest wall 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 S29.091AOverview

Is S29.091A (Other injury of muscle and tendon of front wall of thorax) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other injury of muscle and tendon of front wall of thorax, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in S29.091A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for other injury of muscle and tendon of front wall of thorax, such as an emergency visit or first evaluation.

What MS-DRG does S29.091A group to?

When other injury of muscle and tendon of front wall 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 S29.091A?

Under the General Equivalence Mappings, other injury of muscle and tendon of front wall 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.