2026 ICD-10-CM Diagnosis Code S43.50XASprain of unspecified acromioclavicular joint, initial encounter
S43.50XA is a billable ICD-10-CM diagnosis code for sprain of unspecified acromioclavicular joint, 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 562 through 563, 963 through 965. Coders also document this condition as rupture of acromioclavicular ligament. 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.
- Rupture of acromioclavicular ligament
- Sprain of acromioclavicular ligament
- Sprain of trapezoid ligament
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments of shoulder girdle (S43). 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
Shoulder Injuries and Disorders
Your shoulder joint is composed of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone). Your shoulders are the most movable joints in your body. They can also be unstable because the ball of the upper arm is larger than the shoulder socket that holds it.
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Convert S43.50XA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S43.50XAOverview
Is S43.50XA (Sprain of unspecified acromioclavicular joint) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report sprain of unspecified acromioclavicular joint, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S43.50XA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for sprain of unspecified acromioclavicular joint, such as an emergency visit or first evaluation.
What MS-DRG does S43.50XA group to?
When sprain of unspecified acromioclavicular joint, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 562, 563, 963, 964, 965, with relative weights from 0.8955 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S43.50XA?
Under the General Equivalence Mappings, sprain of unspecified acromioclavicular joint, initial encounter converts to ICD-9-CM 840.0 (sprain acromioclavicular). 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.
