2026 ICD-10-CM Diagnosis Code T79.A9XSTraumatic compartment syndrome of other sites, sequela
T79.A9XS is a billable ICD-10-CM diagnosis code for traumatic compartment syndrome of other sites, 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 913 through 914. The code is exempt from POA reporting. Coders also document this condition as compartment syndrome of neck due to traumatic injury. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
T79.A9XS 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.
- Compartment syndrome of neck due to traumatic injury
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Certain early complications of trauma, not elsewhere classified (T79). 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
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Convert T79.A9XS to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T79.A9XSOverview
Is T79.A9XS (Traumatic compartment syndrome of other sites) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report traumatic compartment syndrome of other sites, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T79.A9XS mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the traumatic compartment syndrome of other sites itself has resolved, not the original event.
What MS-DRG does T79.A9XS group to?
When traumatic compartment syndrome of other sites, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 913, 914, with relative weights from 0.8855 to 1.6346 depending on complications. Higher weights mean higher Medicare reimbursement.
Is T79.A9XS 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 traumatic compartment syndrome of other sites, sequela on inpatient claims.
What is the ICD-9 equivalent of T79.A9XS?
Under the General Equivalence Mappings, traumatic compartment syndrome of other sites, sequela converts to ICD-9-CM 908.6 (late eff complic trauma). 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.
