Lesion of ulnar nerve, unspecified upper limb

This code signifies a non-traumatic injury or disorder affecting the ulnar nerve, specifically when the laterality (left or right upper limb) is not documented. It represents a lesion that could manifest as sensory disturbances (e.g., numbness, tingling) or motor weakness in the distribution of the ulnar nerve.

Use this code when the physician's documentation clearly indicates an ulnar nerve lesion but does not specify whether it affects the left or right upper limb. This is appropriate for conditions like ulnar neuropathy or entrapment where the exact side is unknown or not recorded.

• Avoid using this code if the laterality is known; instead, select the more specific G56.21 (right) or G56.22 (left).
• Ensure the documentation supports a "lesion" of the nerve, not just symptoms like paresthesia without an identified underlying nerve issue.
• Consider if an external cause code is also needed if the lesion is due to trauma.