2026 ICD-10-CM Diagnosis Code S45.202AUnspecified injury of axillary or brachial vein, left side, initial encounter
S45.202A is a billable ICD-10-CM diagnosis code for unspecified injury of axillary or brachial vein, left side, 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 axillary vein. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury to blood vessels, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Injury of axillary vein
- Injury of brachial vein
- Injury of left axillary vein
- Injury of left brachial vein
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of blood vessels at shoulder and upper arm level (S45). 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
Arm Injuries and Disorders
Of the 206 bones in your body, three of them are in your arm: the humerus, radius, and ulna. Your arms are also made up of muscles, joints, tendons, and other connective tissue. Injuries to any of these parts of the arm can occur during sports, a fall, or an accident.
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Convert S45.202A to ICD-9-CMHistory
Code HistoryHistory
Questions About S45.202AOverview
Is S45.202A (Unspecified injury of axillary or brachial vein, left side) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of axillary or brachial vein, left side, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S45.202A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified injury of axillary or brachial vein, left side, such as an emergency visit or first evaluation.
What MS-DRG does S45.202A group to?
When unspecified injury of axillary or brachial vein, left side, 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 S45.202A?
Under the General Equivalence Mappings, unspecified injury of axillary or brachial vein, left side, initial encounter converts to ICD-9-CM 903.02 (injury axillary vein) and 903.1 (injury brachial vessels). 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.
