Mononeuropathy in diseases classified elsewhere
In Nerve, nerve root and plexus disorders (G50-G59), chapter 6: Diseases of the Nervous System
- G59 is billable and valid on claims for FY 2027. If the record has more detail, check the other codes under G50-G59 below.
- As a secondary diagnosis it is not a CC or MCC, so it doesn't raise the MS-DRG payment.
- Doesn't count toward a Medicare Advantage risk score (no HCC in V28).
- AHRQ's Chronic Condition Indicator classes it as chronic: expected to last 12 months or longer and to limit daily life or need ongoing care.
- Can't be the principal diagnosis: code the underlying condition first. (Manifestation list)
Also indexed as: Mononeuropathy, in diseases classified elsewhere
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Instructional notes
Also applies, from Nerve, nerve root and plexus disorders (G50-G59)
These notes sit on G50-G59 and apply to every code under it, including G59.
Official coding guidelines
From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.
Covers default dominant or nondominant side for hemiplegia and monoplegia, and use and sequencing of G89 pain codes, including postoperative, chronic, and neoplasm-related pain.
- Dominant/nondominant side (page 45)
- Pain - Category G89 (page 45)
Other codes under G50-G59
Nerve, nerve root and plexus disorders (G50-G59)
- G50Disorders of trigeminal nerve
- G51Facial nerve disorders
- G52Disorders of other cranial nerves
- G53Cranial nerve disorders in diseases classified elsewhere
- G54Nerve root and plexus disorders
- G55Nerve root and plexus compressions in diseases classified elsewhere
- G56Mononeuropathies of upper limb
- G57Mononeuropathies of lower limb
- G58Other mononeuropathies
- G59Mononeuropathy in diseases classified elsewhere(this code)
G59 MS-DRGs
As the principal diagnosis, G59 groups to MS-DRG 073 or 074 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.
Related conditions
Grouped by AHRQ's Clinical Classifications Software Refined (CCSR), which sorts every diagnosis code into clinically meaningful categories.
G59 is in Nerve and nerve root disorders (NVS017), with 114 codes. Others in it:
- A17.83 Tuberculous neuritis
- B02.21 Postherpetic geniculate ganglionitis
- B02.22 Postherpetic trigeminal neuralgia
- E08.41 Diabetes mellitus due to underlying condition with diabetic mononeuropathy
- E09.41 Drug or chemical induced diabetes mellitus with neurological complications with diabetic mononeuropathy
- E10.41 Type 1 diabetes mellitus with diabetic mononeuropathy
- E11.41 Type 2 diabetes mellitus with diabetic mononeuropathy
- E13.41 Other specified diabetes mellitus with diabetic mononeuropathy
Medicare coverage articles listing G59
These 10 Medicare billing and coding articles list G59 as a diagnosis that supports medical necessity for the services they cover. From the CMS Medicare Coverage Database; check your own contractor's article before billing.
- Nerve Conduction Studies and Electromyography (7 contractors)
- MolDX: Molecular Testing for Identification and Management of Hereditary Transthyretin Amyloidosis (4 contractors)
- Peripheral Nerve Blocks (2 contractors)
- Continuous Peripheral Nerve Blocks (CPNB)
- Lumbar MRI
- MRI and CT Scans of the Head and Neck
- Nerve Blockade for Treatment of Chronic Pain and Neuropathy
- Outpatient Occupational Therapy
- Peripheral Nerve Stimulation
- Spinal Cord Stimulators for Chronic Pain
About the condition
Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.
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. Peripheral nerves carry messages from your brain that control your movement, breathing, heartbeat, digestion, and more. They also carry messages from your body to your brain, so you can feel things, such as pain, heat, and cold.
Read more about peripheral nerve disorders on MedlinePlusCode history
Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.
ICD-9-CM equivalent
Legacy crosswalk from the CMS General Equivalence Mappings (last updated 2018).
- 355.9 Mononeuritis of unspecified site (approximate)