2026 ICD-10-CM Diagnosis Code S29.012SStrain of muscle and tendon of back wall of thorax, sequela
S29.012S is a billable ICD-10-CM diagnosis code for strain of muscle and tendon of back wall 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
S29.012S 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.
- Injury of muscle of neck
- Left shoulder skeletal muscle injury
- Right shoulder skeletal muscle injury
- Strain of back muscle
- Strain of left rhomboid muscle
- Strain of left trapezius muscle
- Strain of muscle at thorax level
- Strain of muscle of chest wall
- Strain of muscle of left shoulder
- Strain of muscle of right shoulder
- Strain of neck muscle
- Strain of right rhomboid muscle
- Strain of right trapezius muscle
- Strain of shoulder muscle
- Strain of trapezius muscle
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 2026, published by CMS and the National Center for Health Statistics.
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 S29.012S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S29.012SOverview
Is S29.012S (Strain of muscle and tendon of back wall of thorax) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report strain of muscle and tendon of back wall of thorax, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in S29.012S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the strain of muscle and tendon of back wall of thorax itself has resolved, not the original event.
What MS-DRG does S29.012S group to?
When strain of muscle and tendon of back wall 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 S29.012S 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 strain of muscle and tendon of back wall of thorax, sequela on inpatient claims.
What is the ICD-9 equivalent of S29.012S?
Under the General Equivalence Mappings, strain of muscle and tendon of back wall 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.
