M66.862
Spontaneous rupture of other tendons, left lower leg
M66.862 (also written M66862) is a billable ICD-10-CM diagnosis code for spontaneous rupture of other tendons, left lower leg. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 103 codes in category M66 (Spontaneous rupture of synovium and tendon). Its coding notes include 12 Excludes2 entries.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
- rotator cuff syndrome (M75.1-)
- rupture where an abnormal force is applied to normal tissue - see injury of tendon by body region
Also from chapter/block level (10 notes)
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the Musculoskeletal Rehabilitation clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026Includes
Further defines or gives examples of the content of the category.
- rupture that occurs when a normal force is applied to tissues that are inferred to have less than normal strength
Notes
Also from chapter/block level (1 note)
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition