Oth and unsp soft tissue disorders, not elsewhere classified

M79.0 classifies rheumatism when the clinical documentation does not specify a more precise rheumatic condition — a soft tissue disorder catch-all under the M79 parent category.

M79.2 captures nerve pain — including burning, shooting, or aching along a nerve distribution — when no specific etiology, named nerve, or structural cause has been identified or documented.

Inflammation of the subcutaneous fat (panniculitis) where the specific subtype or etiology has not been documented or identified.

Enlargement or hypertrophy of the infrapatellar (Hoffa's) fat pad, a soft tissue structure anterior to the knee joint and posterior to the patellar tendon, classified under other soft tissue disorders.

M79.5 classifies a retained or old foreign body lodged within soft tissue — muscle, fascia, tendon, or connective tissue — that was not removed at the time of the original injury or procedure and persists as a chronic finding.

M79.7 is the single billable ICD-10-CM code covering fibromyalgia, a chronic nonarticular musculoskeletal syndrome marked by widespread myalgia and multiple tender points. It also captures the synonymous terms fibromyositis, fibrositis, and myofibrositis under its 'Applicable To' annotations.

M79.9 identifies a soft tissue disorder affecting muscles, tendons, ligaments, or fascia where the clinical record does not support a more specific diagnosis code.