2026 ICD-10-CM Diagnosis Code M66.142Rupture of synovium, left hand
ICD-10-CM Codes›M00–M99›M65-M67›M66
- Billable — Valid for Submission
- Not Chronic
M66.142 is a billable ICD-10-CM diagnosis code for rupture of synovium, left hand. 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
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Hand Injuries and Disorders
No matter how old you are or what you do for a living, you are always using your hands. When there is something wrong with them, you may not be able to do your regular activities.
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Convert M66.142 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M66.142Overview
Is M66.142 (Rupture of synovium, hand and fingers) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report rupture of synovium, left hand on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does M66.142 group to?
When rupture of synovium, left hand 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 M66.142?
Under the General Equivalence Mappings, rupture of synovium, left hand converts to ICD-9-CM 727.59 (rupture of synovium NEC). 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.
