2026 ICD-10-CM Diagnosis Code S04.70XSInjury of accessory nerve, unspecified side, sequela
S04.70XS is a billable ICD-10-CM diagnosis code for injury of accessory nerve, unspecified side, 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). The code is exempt from POA reporting. Coders also document this condition as closed injury, accessory nerve. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
S04.70XS 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.
- Closed injury, accessory nerve
- Injury of accessory nerve
- Open injury, accessory nerve
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of cranial nerve (S04). 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
Neuromuscular Disorders
Neuromuscular disorders affect your neuromuscular system. They can cause problems with:
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Convert S04.70XS to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S04.70XSOverview
Is S04.70XS (Injury of accessory nerve, unspecified side) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report injury of accessory nerve, unspecified side, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in S04.70XS mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the injury of accessory nerve, unspecified side itself has resolved, not the original event.
Is S04.70XS 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 injury of accessory nerve, unspecified side, sequela on inpatient claims.
What is the ICD-9 equivalent of S04.70XS?
Under the General Equivalence Mappings, injury of accessory nerve, unspecified side, sequela converts to ICD-9-CM 907.1 (late eff cran nerve inj). 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.
