M66
⚠ Non-billable
Spontaneous rupture of synovium and tendon
ICD-10-CM · FY2026 · Diseases of the Musculoskeletal System and Connective Tissue
Code
M66
System
ICD-10-CM
Billable
No — use specific code
Effective
FY2026
Chapter
Diseases of the Musculoskeletal System and Connective Tissue
Source
CMS / CDC NCHS
⚠ Verify before billing. Confirm against the current CMS/NCHS ICD-10-CM files and your payer's rules before claims submission.
Official coding notes
From CMS's ICD-10-CM Tabular List.
Includes
- rupture that occurs when a normal force is applied to tissues that are inferred to have less than normal strength
Excludes2 — not included here, but may code together
- rotator cuff syndrome (M75.1-)
- rupture where an abnormal force is applied to normal tissue - see injury of tendon by body region
Frequently asked questions
What is ICD-10 code M66?
ICD-10-CM code M66 represents Spontaneous rupture of synovium and tendon. It is a non-billable header code requiring a more specific subcategory in the Diseases of the Musculoskeletal System and Connective Tissue chapter, effective October 1, 2025 – September 30, 2026.
Is M66 billable?
No. M66 is a non-billable header. Select a more specific subcategory for claims submission.
What chapter is M66 in?
M66 belongs to the Diseases of the Musculoskeletal System and Connective Tissue chapter (M00–M99) of ICD-10-CM.
Related codes in the M66 category
M66.0
Rupture of popliteal cyst
Billable
M66.1
Rupture of synovium
Non-billable
M66.2
Spontaneous rupture of extensor tendons
Non-billable
M66.10
Rupture of synovium, unspecified joint
Billable
M66.11
Rupture of synovium, shoulder
Non-billable
M66.12
Rupture of synovium, elbow
Non-billable
M66.13
Rupture of synovium, wrist
Non-billable
M66.14
Rupture of synovium, hand and fingers
Non-billable
Search all 98,186 ICD-10-CM codes instantly
Search ICDwise →