Chronic osteomyelitis with draining sinus, unspecified site

This code signifies a long-standing bone infection that has created a persistent tract or opening to the skin, allowing pus or fluid to drain. It indicates a chronic inflammatory process within the bone marrow and cortex, characterized by the presence of a draining sinus, without specifying the affected anatomical location.

Apply this code when documentation clearly states chronic osteomyelitis with an associated draining sinus, and the specific bone or site is not identified. This diagnosis is typically supported by imaging studies (e.g., X-ray, MRI, bone scan) showing chronic osteomyelitis and clinical notes describing a persistent draining fistula.

• Ensure documentation explicitly states "chronic" osteomyelitis and the presence of a "draining sinus."
• If the specific site of osteomyelitis is known, a more specific code from the M86.4- subcategory should be used.
• Do not use this code for acute osteomyelitis or osteomyelitis without a draining sinus.