M63.86
Disorders of muscle in diseases classified elsewhere, lower leg
M63.86 is a non-billable ICD-10-CM code header for disorders of muscle in diseases classified elsewhere, lower leg. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are M63.861 Disorders of muscle in diseases classified elsewhere, right lower leg; M63.862 Disorders of muscle in diseases classified elsewhere, left lower leg and M63.869 Disorders of muscle in diseases classified elsewhere, unspecified lower leg. Its coding notes include a Code first instruction, 15 Excludes1 entries and 11 Excludes2 entries.
Code first
If the underlying condition listed here is present and known, sequence it first.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Also from chapter/block level (7 notes)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (11 notes)
- muscular dystrophies and myopathies (G71-G72)
- 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)
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
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 3 entries