ICD-10-CM 2027
ICD-10 code for nervous system disorder
From the official ICD-10-CM alphabetic index entry “Disorder (of) › nervous system”. Page updated September 29, 2026.
About coding nervous system disorder
The ICD-10-CM code for nervous system disorder is G98.8 (Other disorders of nervous system). The official index lists 8 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on G98.8.
Within G98, choose G98.8 (Other disorders of nervous system) only when documentation doesn't support a more specific option: neurogenic arthritis, not elsewhere classified (G98.0).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 070 (Other Cerebrovascular Disorders with MCC, relative weight 1.6093), DRG 071 (Other Cerebrovascular Disorders with CC, relative weight 1.0177), DRG 072 (Other Cerebrovascular Disorders without CC/MCC, relative weight 0.7348), DRG 974 (HIV with Major Related Condition with MCC, relative weight 3.0506), DRG 975 (HIV with Major Related Condition with CC, relative weight 1.3252) and DRG 976 (HIV with Major Related Condition without CC/MCC, relative weight 0.8124), in MDC 01 (Diseases and Disorders of the Nervous System) and MDC 25 (Human Immunodeficiency Virus Infections), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific nervous system disorder codes (official index)
- autonomic (peripheral) G90.9 — Disorder of the autonomic nervous system, unspecified
- specified NEC G90.89 — Other disorders of autonomic nervous system
- central G96.9 — Disorder of central nervous system, unspecified
- specified NEC G96.89 — Other specified disorders of central nervous system
- parasympathetic G90.9 — Disorder of the autonomic nervous system, unspecified
- specified NEC G98.8 — Other disorders of nervous system
- sympathetic G90.9 — Disorder of the autonomic nervous system, unspecified
- vegetative G90.9 — Disorder of the autonomic nervous system, unspecified
Common questions about nervous system disorder ICD-10 codes
What is the ICD-10 code for nervous system disorder?
- G98.8 — Other disorders of nervous system. More specific codes apply when the documentation supports them: G90.9, G90.89, G96.9, G96.89 and others below.
What is the ICD-10 code for autonomic nervous system disorder?
- G90.9 — Disorder of the autonomic nervous system, unspecified.
What is the ICD-10 code for central nervous system disorder?
- G96.9 — Disorder of central nervous system, unspecified.
What is the ICD-10 code for parasympathetic nervous system disorder?
- G90.9 — Disorder of the autonomic nervous system, unspecified.
What is the ICD-10 code for sympathetic nervous system disorder?
- G90.9 — Disorder of the autonomic nervous system, unspecified.
What is the ICD-10 code for vegetative nervous system disorder?
- G90.9 — Disorder of the autonomic nervous system, unspecified.
Is G98.8 billable?
- Yes. G98.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can G98.8 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict G98.8 as a principal diagnosis.
Is G98.8 a CC or MCC?
- No. G98.8 is neither a CC nor an MCC under MS-DRG v44.0.