G56.91 ICD-10-CM Code: Unspecified mononeuropathy of right upper limb

G56.91 is the ICD-10-CM diagnosis code for unspecified mononeuropathy of right upper limb. This code describes nerve damage affecting a single nerve in the right arm, but the specific nerve involved has not been identified or documented. The condition causes weakness, numbness, or pain in the affected arm. G56.91 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering nerve, nerve root and plexus disorders (g50-g59).

G56.91 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Query the provider if more specific nerve involvement can be documented (e.g., radial, ulnar, median nerve) as this would allow for a more specific code and better clinical clarity.