Other rupture of muscle (nontraumatic), unspecified forearm

This code signifies a spontaneous, non-traumatic tear or disruption of muscle tissue within an unspecified forearm. This condition typically results from underlying muscle degeneration, overuse, or systemic disease rather than an acute external injury. It describes the anatomical location of the rupture without specifying the exact muscle involved.

Apply this code when documentation indicates a non-traumatic muscle rupture in the forearm, and the specific muscle affected is not identified. This is appropriate for conditions like spontaneous tears due to chronic tendinopathy or myopathy. Ensure the physician explicitly states the rupture is "nontraumatic" or provides clinical context supporting a non-injury etiology.

• Differentiate from traumatic muscle ruptures (S46.3-S46.9 for forearm muscle/tendon injuries).
• Avoid if a specific forearm muscle is documented; instead, use a more precise M62.13- subcategory.
• Query the provider for clarification if the etiology (traumatic vs. nontraumatic) or specific muscle is unclear.