2026 ICD-10-CM Diagnosis Code S56.329SLaceration of extensor or abductor muscles, fascia and tendons of unspecified thumb at forearm level, sequela
S56.329S is a billable ICD-10-CM diagnosis code for laceration of extensor or abductor muscles, fascia and tendons of unspecified thumb at forearm level, 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 604 through 605. 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
S56.329S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of muscle, fascia and tendon at forearm level (S56). 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
Arm Injuries and Disorders
Of the 206 bones in your body, three of them are in your arm: the humerus, radius, and ulna. Your arms are also made up of muscles, joints, tendons, and other connective tissue. Injuries to any of these parts of the arm can occur during sports, a fall, or an accident.
Read the full article at MedlinePlus
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Convert S56.329S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S56.329SOverview
Is S56.329S a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report laceration of extensor or abductor muscles, fascia and tendons of unspecified thumb at forearm level, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in S56.329S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the laceration of extensor or abductor muscles, fascia and tendons of unspecified thumb at forearm level itself has resolved, not the original event.
What MS-DRG does S56.329S group to?
When laceration of extensor or abductor muscles, fascia and tendons of unspecified thumb at forearm level, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, with relative weights from 0.9160 to 1.4721 depending on complications. Higher weights mean higher Medicare reimbursement.
Is S56.329S 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 laceration of extensor or abductor muscles, fascia and tendons of unspecified thumb at forearm level, sequela on inpatient claims.
What is the ICD-9 equivalent of S56.329S?
Under the General Equivalence Mappings, laceration of extensor or abductor muscles, fascia and tendons of unspecified thumb at forearm level, sequela converts to ICD-9-CM 906.1 (late eff open wnd extrem). 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.
