Diseases of the nervous system (G00–G99) ICD-10-CM
Chapter 6 of the ICD-10-CM classification spans codes G00–G99 and contains 932 diagnosis codes for diseases of the nervous system, of which 700 are billable. The chapter is organized into 11 sections listed below, each linking to its code ranges and individual codes.
Chapter Coding Notes
Excludes2: 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)
Sections in This Chapter 11 ranges · 932 codes
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
About Chapter 6
These conditions affect the nervous system, including its nerves, the brain and spinal cord, and the connection between nerves and muscles.
The blocks separate inflammation, tissue shrinkage primarily affecting the brain and spinal cord, movement disorders, and other conditions involving deterioration of nervous system tissue. Another block groups diseases affecting the covering of nerve fibers.
Other blocks group disorders that occur in episodes; disorders of nerves, nerve roots, and nerve networks; and conditions affecting many peripheral nerves. The remaining blocks cover the connection between nerves and muscles, muscle disease, cerebral palsy, other paralysis syndromes, and other nervous system disorders.
FY 2027 changes: The FY 2027 ICD-10-CM update, effective October 1, 2026, deleted 1 code in this chapter.
Questions About This Page
How many codes are in the G00-G99 range?
The G00-G99 range contains 932 ICD-10-CM diagnosis codes in FY 2027. 700 of them are billable, and the rest are category headers that organize the chapter.
What conditions does G00-G99 cover?
The range covers diseases of the nervous system. The sections listed above break it into groups of related conditions, and each one links to its own page with the full code list.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
