Chronic multifocal osteomyelitis, unspecified shoulder

This code signifies a persistent, widespread bone infection affecting multiple sites within the shoulder region, without specifying the exact location (e.g., humerus, scapula, clavicle). It indicates an ongoing inflammatory process within the bone marrow and cortical bone, often leading to bone destruction and new bone formation.

Apply this code when documentation explicitly states "chronic multifocal osteomyelitis" involving an unspecified shoulder. This diagnosis is typically supported by imaging studies (X-ray, MRI, bone scan) showing characteristic changes of chronic osteomyelitis, along with clinical signs and symptoms of persistent infection.

• Ensure documentation clearly specifies "chronic" and "multifocal" to differentiate from acute or localized osteomyelitis.
• If a specific bone within the shoulder is identified (e.g., humerus, scapula), use a more specific code from the M86.31- subcategory.
• Always code the underlying infectious agent (e.g., B95-B97) as an additional diagnosis, if known.