ICD-10 Code G57.40 – Lesion of medial popliteal nerve, unspecified lower limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G57.40 – Lesion of medial popliteal nerve, unspecified lower limb
What it is
This code identifies a lesion or disorder affecting the medial popliteal nerve in an unspecified lower limb. Use it when documentation names that nerve problem but does not specify the side.
Clinical signs
Clinical features may include pain, numbness, tingling, or weakness in the nerve distribution. Findings depend on the underlying lesion; if documentation is limited, check documentation.
When to use this code
Use G57.40 when the provider documents a lesion of the medial popliteal nerve and does not identify the right or left lower limb. It also fits follow-up notes that carry the same documented diagnosis without added laterality.
If the record describes a different peripheral nerve, a more specific entrapment, or a clearly stated side, choose the documented, more precise code instead. When the note is vague, code only what is supported.
Do not use for
Do not use this code for sciatica, generalized neuropathy, or lesions of other named nerves. It is also inappropriate when the record specifies a different lower-limb side.
Coding tip
Look for laterality in the assessment and imaging or exam notes before assigning the unspecified code.