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  3. M00–M99
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  5. Disorders of muscle in diseases classified elsewhere (M63)

Disorders of muscle in diseases classified elsewhere (M63)

The ICD-10-CM codes in the M63 category are specifically used to identify and classify muscle disorders that occur as part of other underlying diseases. These codes capture muscle involvement related to various illnesses rather than primary muscle diseases.

This section details disorders of muscle appearing in other diseases, with codes like M63.80 covering unspecified muscle sites and including conditions such as generalized congenital lipodystrophy with myopathy and parasitic myositis. More precise codes like M63.811 or M63.852 specify the side and exact location; such as the right shoulder or left thigh; where muscle complications are linked to another disease. This distinction helps medical coders assign the correct ICD-10 code for muscle problems as secondary to systemic or infectious conditions, rather than standalone muscle disorders. Knowing these codes aids in accurate documentation for complex cases involving muscles affected by broader diseases.

  • Diseases of the musculoskeletal system and connective tissue (M00–M99)

    • Disorders of muscles (M60-M63)

        • Disorders of muscle in diseases classified elsewhere (M63)

        • M63 Disorders of muscle in diseases classified elsewhere
        • M63.8 Disorders of muscle in diseases classified elsewhere
        • M63.80 Disorders of muscle in diseases classified elsewhere, unspecified site
        • M63.81 Disorders of muscle in diseases classified elsewhere, shoulder
        • M63.811 Disorders of muscle in diseases classified elsewhere, right shoulder
        • M63.812 Disorders of muscle in diseases classified elsewhere, left shoulder
        • M63.819 Disorders of muscle in diseases classified elsewhere, unspecified shoulder
        • M63.82 Disorders of muscle in diseases classified elsewhere, upper arm
        • M63.821 Disorders of muscle in diseases classified elsewhere, right upper arm
        • M63.822 Disorders of muscle in diseases classified elsewhere, left upper arm
        • M63.829 Disorders of muscle in diseases classified elsewhere, unspecified upper arm
        • M63.83 Disorders of muscle in diseases classified elsewhere, forearm
        • M63.831 Disorders of muscle in diseases classified elsewhere, right forearm
        • M63.832 Disorders of muscle in diseases classified elsewhere, left forearm
        • M63.839 Disorders of muscle in diseases classified elsewhere, unspecified forearm
        • M63.84 Disorders of muscle in diseases classified elsewhere, hand
        • M63.841 Disorders of muscle in diseases classified elsewhere, right hand
        • M63.842 Disorders of muscle in diseases classified elsewhere, left hand
        • M63.849 Disorders of muscle in diseases classified elsewhere, unspecified hand
        • M63.85 Disorders of muscle in diseases classified elsewhere, thigh
        • M63.851 Disorders of muscle in diseases classified elsewhere, right thigh
        • M63.852 Disorders of muscle in diseases classified elsewhere, left thigh
        • M63.859 Disorders of muscle in diseases classified elsewhere, unspecified thigh
        • M63.86 Disorders of muscle in diseases classified elsewhere, lower leg
        • M63.861 Disorders of muscle in diseases classified elsewhere, right lower leg
        • M63.862 Disorders of muscle in diseases classified elsewhere, left lower leg
        • M63.869 Disorders of muscle in diseases classified elsewhere, unspecified lower leg
        • M63.87 Disorders of muscle in diseases classified elsewhere, ankle and foot
        • M63.871 Disorders of muscle in diseases classified elsewhere, right ankle and foot
        • M63.872 Disorders of muscle in diseases classified elsewhere, left ankle and foot
        • M63.879 Disorders of muscle in diseases classified elsewhere, unspecified ankle and foot
        • M63.88 Disorders of muscle in diseases classified elsewhere, other site
        • M63.89 Disorders of muscle in diseases classified elsewhere, multiple sites

Instructional Notations

Code First

Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

  • 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