G99.8 – Other specified disorders of nervous system in diseases classified elsewhere

ICD-10-CM 2027 diagnosis code · Other disorders of the nervous system

Billable code

ICD-10-CM code G99.8
Code
G99.8 (claims format: G998)
Description
Other specified disorders of nervous system in diseases classified elsewhere
Short description
Oth disrd of nervous system in diseases classified elsewhere
Billable
Yes – valid for HIPAA-covered transactions
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
6. Diseases of the nervous system (G00-G99)
Block
G89-G99 Other disorders of the nervous system
Parent codes
G99

Notes for G99.8

Excludes1 (not coded here):
  • nervous system involvement in:
  • cysticercosis (B69.0)
  • rubella (B06.0-)
  • syphilis (A52.1-)
Code first:
  • underlying disorder, such as:
  • amyloidosis (E85.-)
  • avitaminosis (E56.-)

Index terms for G99.8

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in G99

Frequently asked questions

What is ICD-10 code G99.8?

G99.8 is the ICD-10-CM code for other specified disorders of nervous system in diseases classified elsewhere, in the block G89-G99 (Other disorders of the nervous system).

Is G99.8 a billable code?

Yes. G99.8 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does G99.8 belong to?

It belongs to category G99 – Other disorders of nervous system in diseases classified elsewhere.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.