2026 ICD-10-CM Diagnosis Code S65.412ALaceration of blood vessel of left thumb, initial encounter
S65.412A is a billable ICD-10-CM diagnosis code for laceration of blood vessel of left thumb, 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 blood vessel of left thumb. 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 blood vessel of left thumb
- Injury of blood vessel of thumb
- Laceration of blood vessel of left thumb
- Laceration of blood vessel of thumb
- Laceration of left thumb
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of blood vessels at wrist and hand level (S65). 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
Finger Injuries and Disorders
You use your fingers and thumbs to do everything from grasping objects to playing musical instruments to typing. When there is something wrong with them, it can make life difficult. Common problems include:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S65.412A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S65.412AOverview
Is S65.412A (Laceration of blood vessel of left thumb) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report laceration of blood vessel of left thumb, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S65.412A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for laceration of blood vessel of left thumb, such as an emergency visit or first evaluation.
What MS-DRG does S65.412A group to?
When laceration of blood vessel of left thumb, 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 S65.412A?
Under the General Equivalence Mappings, laceration of blood vessel of left thumb, initial encounter converts to ICD-9-CM 903.5 (injury finger 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.
