Muscle wasting and atrophy, not elsewhere classified, back, thoracic

• 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)

Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

• 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.-)

muscular dystrophies and myopathies (G71-G72)

• alcoholic myopathy (G72.1)
• cramp and spasm (R25.2)
• drug-induced myopathy (G72.0)
• myalgia (M79.1-)
• stiff-man syndrome (G25.82)

nontraumatic hematoma of muscle (M79.81)

Disuse atrophy NEC

• neuralgic amyotrophy (G54.5)
• progressive muscular atrophy (G12.21)
• sarcopenia (M62.84)

pelvic muscle wasting (N81.84)