Other specified mononeuropathies of unspecified lower limb

This code signifies a mononeuropathy affecting a single nerve in an unspecified lower limb, where the specific nerve involved is known but does not have a more precise ICD-10-CM code. It represents nerve damage or dysfunction presenting with symptoms like pain, numbness, weakness, or paresthesia in a localized area of the leg or foot. This diagnosis is used when the etiology is not specified or is secondary to another condition.

Use this code when documentation clearly identifies a mononeuropathy of a lower limb, but the specific nerve (e.g., peroneal, tibial, sural) is not explicitly stated or a more specific code for that nerve is unavailable. This applies to cases where the laterality (right or left) is also not documented. Supporting documentation would include physician notes detailing neurological deficits consistent with a mononeuropathy, without further specification of the affected nerve or laterality.

• Avoid using this code if the specific nerve (e.g., common peroneal nerve) is documented; look for more precise codes within the G57 series.
• Do not use if laterality (right or left lower limb) is specified; instead, select G57.81 for right or G57.82 for left.
• Always query the provider for more specific nerve identification and laterality if possible to ensure the highest level of specificity.