2026 ICD-10-CM Diagnosis Code S16.9XXAUnspecified injury of muscle, fascia and tendon at neck level, initial encounter
S16.9XXA is a billable ICD-10-CM diagnosis code for unspecified injury of muscle, fascia and tendon at neck level, 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 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 913 through 914, 963 through 965. Coders also document this condition as injury of fascia of neck. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury to nerves, muscles and tendons, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Injury of fascia of neck
- Injury of muscle and tendon at neck level
- Injury of muscle of neck
- Injury of tendon of neck
- Traumatic division of tendon of head and neck
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of muscle, fascia and tendon at neck level (S16). 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
Neck Injuries and Disorders
Any part of your neck - muscles, bones, joints, tendons, ligaments, or nerves - can cause neck problems. Neck pain is very common. Pain may also come from your shoulder, jaw, head, or upper arms.
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Convert S16.9XXA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S16.9XXAOverview
Is S16.9XXA a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of muscle, fascia and tendon at neck level, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S16.9XXA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified injury of muscle, fascia and tendon at neck level, such as an emergency visit or first evaluation.
What MS-DRG does S16.9XXA group to?
When unspecified injury of muscle, fascia and tendon at neck level, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 913, 914, 963, 964, 965, with relative weights from 0.8855 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S16.9XXA?
Under the General Equivalence Mappings, unspecified injury of muscle, fascia and tendon at neck level, initial encounter converts to ICD-9-CM 959.09 (face & neck injury). 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.
