2026 ICD-10-CM Diagnosis Code G56.21Lesion of ulnar nerve, right upper limb

ICD-10-CM Codes›G00–G99›G50-G59›G56

ICD-10-CM G56.21
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G56.21 is a billable ICD-10-CM diagnosis code for lesion of ulnar nerve, right upper limb. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nerve and nerve root disorders.

Code Identity

ICD-10-CM Code
G56.21
Billable Status
Yes — Valid for Submission
Code Describes
Lesion of ulnar nerve, right upper limb
Short Description
Lesion of ulnar nerve, right upper limb
Same as the full description in the CMS dataset.
Parent Code
G56.2
Lesion of ulnar nerve

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG50-G59Nerve, nerve root and plexus disorders
CategoryG56Mononeuropathies of upper limb
This CodeG56.21Lesion of ulnar nerve, right upper limb

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Entrapment of right ulnar nerve
  • Entrapment of right ulnar nerve at elbow
  • Entrapment of ulnar nerve at right wrist
  • Inflammation of peripheral nerve of right upper limb
  • Lesion of right ulnar nerve
  • Neuritis of right ulnar nerve
  • Tardy right ulnar nerve palsy
  • Tardy ulnar nerve palsy
  • Ulnar nerve entrapment at elbow
  • Ulnar nerve entrapment at wrist
  • Ulnar nerve palsy
  • Ulnar neuritis
  • Ulnar neuropathy at wrist
  • Ulnar neuropathy of right arm

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS017
Nerve and nerve root disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Peripheral Nerve Disorders

Nerves are like wires that carry messages back and forth between your brain and your body. Your peripheral nerves branch off from your brain and spinal cord and connect to all parts of your body, including your muscles and organs.

The full article covers:

  • What are peripheral nerves?
  • What are peripheral nerve disorders?
  • What causes peripheral nerve disorders?
  • What are the symptoms of peripheral nerve disorders?
  • How are peripheral nerve disorders diagnosed?
  • What are the treatments for peripheral nerve disorders?
  • Can peripheral nerve disorders be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G56.21 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
354.2 Ulnar nerve lesion
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About G56.21Overview

Is G56.21 (Lesion of ulnar nerve) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report lesion of ulnar nerve, right upper limb on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of G56.21?

Under the General Equivalence Mappings, lesion of ulnar nerve, right upper limb converts to ICD-9-CM 354.2 (ulnar nerve lesion). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.