M63.8 – Disorders of muscle in diseases classified elsewhere

ICD-10-CM 2027 diagnosis code · Disorders of muscles

Non-billable header

ICD-10-CM code M63.8

Code: M63.8 (claims format: M638)
Description: Disorders of muscle in diseases classified elsewhere
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
Block: M60-M63 Disorders of muscles
Parent codes: M63

Billable codes under M63.8

M63.8 is a header code and cannot be used on claims. Choose the most specific code:

M63.80 – Disorders of muscle in diseases classified elsewhere, unspecified siteBillable
M63.81 – Disorders of muscle in diseases classified elsewhere, shoulderHeader (more codes below)
M63.82 – Disorders of muscle in diseases classified elsewhere, upper armHeader (more codes below)
M63.83 – Disorders of muscle in diseases classified elsewhere, forearmHeader (more codes below)
M63.84 – Disorders of muscle in diseases classified elsewhere, handHeader (more codes below)
M63.85 – Disorders of muscle in diseases classified elsewhere, thighHeader (more codes below)
M63.86 – Disorders of muscle in diseases classified elsewhere, lower legHeader (more codes below)
M63.87 – Disorders of muscle in diseases classified elsewhere, ankle and footHeader (more codes below)
M63.88 – Disorders of muscle in diseases classified elsewhere, other siteBillable
M63.89 – Disorders of muscle in diseases classified elsewhere, multiple sitesBillable

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

M63 – Disorders of muscle in diseases classified elsewhere

Excludes1 (not coded here):

myopathy in cysticercosis (B69.81)
myopathy in endocrine diseases (G73.7)
myopathy in metabolic diseases (G73.7)
myopathy in sarcoidosis (D86.87)
myopathy in secondary syphilis (A51.49)
myopathy in syphilis (late) (A52.78)
myopathy in toxoplasmosis (B58.82)
myopathy in tuberculosis (A18.09)

Code first:

underlying disease, such as:
leprosy (A30.-)
neoplasm (C49.-, C79.89, D21.-, D48.1-)
schistosomiasis (B65.-)
trichinellosis (B75)

Block M60-M63

Excludes1 (not coded here):

dermatopolymyositis (M33.-)
myopathy in amyloidosis (E85.-)
myopathy in polyarteritis nodosa (M30.0)
myopathy in rheumatoid arthritis (M05.32)
myopathy in scleroderma (M34.-)
myopathy in Sjögren's syndrome (M35.03)
myopathy in systemic lupus erythematosus (M32.-)

Excludes2 (not included here):

muscular dystrophies and myopathies (G71-G72)

Index terms for M63.8

Entries in the ICD-10-CM alphabetic index that lead to this code:

Frequently asked questions

What is ICD-10 code M63.8?

M63.8 is the ICD-10-CM code for disorders of muscle in diseases classified elsewhere, in the block M60-M63 (Disorders of muscles).

Is M63.8 a billable code?

No. M63.8 is a header code with more specific child codes; report one of the billable codes listed above.

What category does M63.8 belong to?

It belongs to category M63 – Disorders of muscle in diseases classified elsewhere.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.