2027 ICD-10-CM Diagnosis Code G59Mononeuropathy in diseases classified elsewhere

ICD-10-CM Codes›G00–G99›G50-G59›G59

ICD-10-CM G59
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G59 is a billable ICD-10-CM diagnosis code for mononeuropathy in diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 73 through 74. The code is a manifestation code that cannot be reported as the principal diagnosis. Coders also document this condition as neuropathy in arteriosclerotic occlusive disease. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nerve and nerve root disorders.

Code Identity

ICD-10-CM Code
G59
Billable Status
Yes — Valid for Submission
Code Describes
Mononeuropathy in diseases classified elsewhere
Short Description
Mononeuropathy in diseases classified elsewhere
Same as the full description in the CMS dataset.
Chapter
G50-G59
Nerve, nerve root and plexus disorders

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG50-G59Nerve, nerve root and plexus disorders
CategoryG59Mononeuropathy in diseases classified elsewhere
This CodeG59Mononeuropathy in diseases classified elsewhere

Code EditsBilling

Medicare Code Editor checks that affect claim validity for G59.

Manifestation diagnoses
Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and therefore should not be used as a principal diagnosis.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Neuropathy in arteriosclerotic occlusive disease
  • Neuropathy in thromboangiitis obliterans

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G59: its own notes plus those printed at block G50-G59 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

On G59 itself
  • diabetic mononeuropathy (E08-E13 with .41)
  • syphilitic nerve paralysis (A52.19)
  • syphilitic neuritis (A52.15)
  • tuberculous mononeuropathy (A17.83)
From Block G50-G59 Nerve, nerve root and plexus disorders applies to 106 codes
  • current traumatic nerve, nerve root and plexus disorders - see Injury, nerve by body region
  • neuralgia NOS (M79.2)
  • neuritis NOS (M79.2)
  • peripheral neuritis in pregnancy (O26.82-)
  • radiculitis NOS (M54.1-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Code First

The underlying condition named in the note is sequenced before this code.

  • underlying disease

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Clinical ClassificationClinical

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

CCSR NVS017
Nerve and nerve root disorders
Default principal diagnosis: inpatient No · outpatient No

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 G59 to ICD-9-CMHistory

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

ICD-9-CM
355.9 Mononeuritis NOS
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G59Overview

What is the ICD-10 code for mononeuropathy in diseases classified elsewhere?

The ICD-10-CM code for mononeuropathy in diseases classified elsewhere is G59. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G59 (Mononeuropathy in diseases classified elsewhere) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report mononeuropathy in diseases classified elsewhere on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G59 group to?

On inpatient claims, mononeuropathy in diseases classified elsewhere maps to MS-DRG 74, 73, with relative weights from 1.0172 to 1.5773 depending on complications. Higher weights mean higher Medicare reimbursement.

Can G59 be a principal diagnosis?

No. This is a manifestation code: mononeuropathy in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.

Can G59 be reported with A52.19?

Not as a rule. The Excludes1 note on G59 lists "syphilitic nerve paralysis (A52.19)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).