2027 ICD-10-CM Diagnosis Code G98.8Other disorders of nervous system

ICD-10-CM Codes›G00–G99›G89-G99›G98

ICD-10-CM G98.8
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G98.8 is a billable ICD-10-CM diagnosis code for other disorders of nervous system. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 70 through 72, 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other nervous system disorders (neither hereditary nor degenerative).

Code Identity

ICD-10-CM Code
G98.8
Billable Status
Yes — Valid for Submission
Code Describes
Other disorders of nervous system
Short Description
Other disorders of nervous system
Same as the full description in the CMS dataset.
Parent Code
G98
Other disorders of nervous system not elsewhere classified

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG89-G99Other disorders of the nervous system
CategoryG98Other disorders of nervous system not elsewhere classified
This CodeG98.8Other disorders of nervous system

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abscess of nervous system
  • Acute nervous system disorder
  • Adenoviral nervous system infection
  • Adverse reaction to yellow fever vaccine
  • Allan-Herndon-Dudley syndrome
  • Bacterial infection of the nervous system
  • Bacterial neuritis
  • Balint syndrome
  • Chronic musculoskeletal pain due to disease of nervous system
  • Chronic musculoskeletal pain due to disorder
  • Chronic nervous system disorder
  • Delayed myelination
  • Disease of nervous system complicating pregnancy, childbirth and puerperium
  • Disorder confirmed
  • Disorder of nervous system
  • Disorder of olfactory system
  • Enteroviral neurological disease
  • Fungal neuritis
  • Hemorrhage into nerve trunk
  • Hereditary disorder of nervous system
  • Heterotopic ossification due to neurological disorder
  • Human immunodeficiency virus infection with neurological disease
  • Hypermelanosis due to nervous system disorder
  • Hypohidrosis
  • Hypohidrosis due to neurological disorder
  • Infantile multisystem neurologic, endocrine, pancreatic disease
  • Infection of peripheral nerve caused by fungus
  • Infection of peripheral nerve caused by Mucorales
  • Infectious disease of nervous system
  • Inherited metabolic disorder of nervous system
  • Lathyrus poisoning
  • Lathyrus sylvestris poisoning
  • Localized hyperhidrosis due to focal neurological disorder
  • Lower motor neuron lesion
  • Nervous system and sense organ diseases
  • Neurologic disorder caused by component of vaccine product containing Yellow fever virus antigen
  • Neurological complication of procedure
  • Neurological disorder caused by alcohol
  • Neurological disorder confirmed
  • Neurological disorder due to and following lumbar puncture
  • Neurological disorder due to excess intake of macronutrients
  • Neurological disorder due to excess intake of micronutrients
  • Neurological disorder due to nutrient deficiency
  • Neurological disorder treatment changed
  • Neurological disorder treatment started
  • Neurological lesion
  • Neuronal intranuclear inclusion disease
  • Pancreatic insufficiency
  • Perinatal neurological disorder
  • Post 5-alpha-reductase inhibitor treatment syndrome
  • Pruritus due to neurological disorder
  • Secondary focal hyperhidrosis
  • Space-occupying lesion of nervous system
  • System disorder of the nervous system
  • X-linked hereditary spastic paraplegia

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G98.8: its own notes plus those printed at G98 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From G98 Other disorders of nervous system not elsewhere classified applies to 2 codes
  • nervous system disorder NOS

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Nervous system disorder NOS

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)

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

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR NVS020
Other nervous system disorders (neither hereditary nor degenerative)
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Neurologic Diseases

The brain, spinal cord, and nerves make up the nervous system. Together they control all the workings of the body. When something goes wrong with a part of your nervous system, you can have trouble moving, speaking, swallowing, breathing, or learning. You can also have problems with your memory, senses, or mood.

Read the full article at MedlinePlus

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

Convert G98.8 to ICD-9-CMHistory

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

ICD-9-CM
349.89 Cns disorder NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
349.9 Cns disorder 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 G98.8Overview

What is the ICD-10 code for other disorders of nervous system?

The ICD-10-CM code for other disorders of nervous system is G98.8 (sometimes written as G988). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G98.8 (Other disorders of nervous system not elsewhere classified) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other disorders of nervous system on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G98.8 group to?

When other disorders of nervous system is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 976, 72, 975, 70, 71, with relative weights from 0.7344 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of G98.8?

Under the General Equivalence Mappings, other disorders of nervous system converts to ICD-9-CM 349.89 (cns disorder NEC) and 349.9 (cns disorder NOS). The mapping is approximate, so confirm the match fits the documentation.