ICD-10 Code G56.20 – Lesion of ulnar nerve, unspecified upper limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G56.20 – Lesion of ulnar nerve, unspecified upper limb
What it is
This code identifies a disorder affecting the ulnar nerve in an upper limb, without specifying whether the right or left side is involved. Use it when documentation confirms ulnar nerve lesion but does not give a more exact site or laterality.
Clinical signs
Typical findings may include numbness or tingling in the ring and little fingers, hand weakness, or reduced grip strength. Clinical features vary; refer to documentation and confirmed exam findings.
When to use this code
Use G56.20 when the provider documents a lesion of the ulnar nerve in an upper limb and laterality is not stated. It also fits records that describe ulnar neuropathy or nerve injury without a more specific codeable detail. If the note identifies right or left side, use the laterality-specific code instead.
Do not use for
Do not use this code for median, radial, or generalized peripheral neuropathies. If documentation is unclear, or another cause is named, check documentation before coding.
Coding tip
Always look for laterality and a more specific ulnar nerve diagnosis before choosing this unspecified code.