2026 ICD-10-CM Diagnosis Code S15.021AMajor laceration of right carotid artery, initial encounter
S15.021A is a billable ICD-10-CM diagnosis code for major laceration of right carotid artery, 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 complete transection of carotid artery. 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.
- Complete transection of carotid artery
- Complete transection of right carotid artery
- Right carotid artery injury
- Transection of carotid artery
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of blood vessels at neck level (S15). 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
Wounds and Injuries
An injury is damage to your body. It is a general term that refers to harm caused by accidents, falls, hits, weapons, and more. In the U.S., millions of people injure themselves every year. These injuries range from minor to life-threatening.
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Convert S15.021A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S15.021AOverview
Is S15.021A (Major laceration of right carotid artery) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report major laceration of right carotid artery, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S15.021A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for major laceration of right carotid artery, such as an emergency visit or first evaluation.
What MS-DRG does S15.021A group to?
When major laceration of right carotid artery, 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 S15.021A?
Under the General Equivalence Mappings, major laceration of right carotid artery, initial encounter converts to ICD-9-CM 900.01 (inj common carotid arter), 900.02 (inj external carotid art), and 900.03 (inj internal carotid art). 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.
