ICD-10 Code G56.91 – Unspecified mononeuropathy of right upper limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G56.91 – Unspecified mononeuropathy of right upper limb
What it is
This code identifies a single-nerve disorder affecting the right upper limb when the exact nerve and cause are not specified. Use it when documentation confirms mononeuropathy but does not name a more precise diagnosis.
Clinical signs
Typical findings include localized numbness, tingling, pain, weakness, or reduced sensation in one nerve distribution of the right arm or hand. Clinical features vary; refer to documentation.
When to use this code
Use G56.91 when the provider documents an unspecified mononeuropathy limited to the right upper limb and no more specific site is recorded. It may fit initial evaluations, incomplete specialty notes, or cases where the nerve cannot yet be identified. Check documentation if laterality or nerve involvement is clarified.
Do not use for
Do not use this code for bilateral, left-sided, or lower-limb mononeuropathy. It is also incorrect when a more specific mononeuropathy, entrapment neuropathy, or another neurologic diagnosis is documented.
Coding tip
Confirm right-sided laterality and unspecified nerve involvement before assigning G56.91.