2026 ICD-10-CM Diagnosis Code M66.232Spontaneous rupture of extensor tendons, left forearm
ICD-10-CM Codes›M00–M99›M65-M67›M66
- Billable — Valid for Submission
- Not Chronic
M66.232 is a billable ICD-10-CM diagnosis code for spontaneous rupture of extensor tendons, left forearm. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 557 through 558. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Tendon and synovial disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Disorder of extensor tendon of left wrist region
- Disorder of extensor tendon of right wrist region
- Disorder of tendon of left forearm
- Injury of tendon of extensor muscle at forearm level
- Nontraumatic rupture of extensor tendon of bilateral wrist regions
- Nontraumatic rupture of extensor tendon of forearm
- Nontraumatic rupture of extensor tendon of left forearm
- Nontraumatic rupture of extensor tendon of left wrist region
- Nontraumatic rupture of extensor tendon of right wrist region
- Nontraumatic rupture of extensor tendon of wrist region
- Rupture wrist extensors
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 M66.232 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M66.232Overview
Is M66.232 (Spontaneous rupture of extensor tendons, forearm) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report spontaneous rupture of extensor tendons, left forearm on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does M66.232 group to?
When spontaneous rupture of extensor tendons, left forearm is the principal diagnosis on an inpatient stay, it groups to MS-DRG 557, 558, with relative weights from 0.8932 to 1.4869 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of M66.232?
Under the General Equivalence Mappings, spontaneous rupture of extensor tendons, left forearm converts to ICD-9-CM 727.63 (rupt exten tendon hand). 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.
