2026 ICD-10-CM Diagnosis Code S16.1XXAStrain of muscle, fascia and tendon at neck level, initial encounter
S16.1XXA is a billable ICD-10-CM diagnosis code for strain 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 551 through 552, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sprains and strains, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Dislocations, sprains and strains involving head with neck
- Dislocations, sprains and strains involving multiple body regions
- Dislocations/sprains/strains
- Injury of muscle of neck
- Injury of tendon of neck
- Kinematic imbalance due to suboccipital strain
- Rupture of tendon of head and neck
- Strain of fascia of neck
- Strain of neck muscle
- Strain of tendon of head and neck
- Strain of tendon of 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.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S16.1XXA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S16.1XXAOverview
Is S16.1XXA (Strain of muscle, fascia and tendon at neck level) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report strain 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 S16.1XXA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for strain of muscle, fascia and tendon at neck level, such as an emergency visit or first evaluation.
What MS-DRG does S16.1XXA group to?
When strain of muscle, fascia and tendon at neck level, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 551, 552, 963, 964, 965, with relative weights from 0.9405 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S16.1XXA?
Under the General Equivalence Mappings, strain of muscle, fascia and tendon at neck level, initial encounter converts to ICD-9-CM 847.0 (sprain of neck). 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.
