G99Header code — not billable
Other disorders of nervous system in diseases classified elsewhere
Short description: Oth disorders of nervous system in diseases classd elswhr
- Chapter
- 6. Diseases of the nervous system
- Category
- G99
- Effective date
- October 1, 2026
Related codes in category G99
Frequently asked questions
What is ICD-10 code G99?
G99 is an ICD-10-CM diagnosis code for Other disorders of nervous system in diseases classified elsewhere.
Is G99 a billable code?
No. G99 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is G99 in?
G99 falls under Chapter 6: Diseases of the nervous system.
When did G99 become effective?
G99 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to G99?
G99 belongs to category G99, which includes 3 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.