G99 ICD-10-CM Code: Other disorders of nervous system in diseases classified elsewhere
A clear reference for the official code description, hierarchy, and related coding information from the FY 2027 U.S. release.
Official description
G99Other disorders of nervous system in diseases classified elsewhere
ICD-10-CM diagnosis code · United States clinical modification
Where G99 sits
- 1
Chapter 6
Diseases of the nervous system (G00-G99)
- 2
Section
Other disorders of the nervous system (G89-G99)
- 3
Category G99
Other disorders of nervous system in diseases classified elsewhere
- 4
Code G99
Other disorders of nervous system in diseases classified elsewhere
Codes under G99
G99 is a non-billable category. Choose the child code that best matches the documented diagnosis.
Notes for this code
Inclusion terms
No inclusion terms are listed for G99.
Code first
No “code first” instruction is listed for G99.
Use additional code
No “use additional code” instruction is listed for G99.
Excludes1
Conditions that should not be reported together with this code.
No Excludes1 note is listed for G99.
Excludes2
Conditions not included here that may be reported separately when present.
No Excludes2 note is listed for G99.
Source and release
- Data release
- U.S. ICD-10-CM · FY 2027
- Effective date
- Oct 1, 2026
- Publisher
- Vero Scribe Inc.
This reference is generated from Vero’s ICD-10-CM description, hierarchy, and code-note dataset. The visible content and structured data share that source.
Frequently asked questions
What does ICD-10-CM code G99 mean?
G99 is the FY 2027 U.S. ICD-10-CM code for “Other disorders of nervous system in diseases classified elsewhere.”
Is G99 a billable or specific ICD-10-CM code?
No. G99 has more specific child codes in the FY 2027 reference data. Select the code that matches the documentation and confirm the active code set and payer requirements.
Where is G99 located in ICD-10-CM?
G99 is listed in Chapter 6, Diseases of the nervous system (G00-G99), within Other disorders of the nervous system (G89-G99) (G89–G99), under category G99, Other disorders of nervous system in diseases classified elsewhere.
What coding notes are listed for G99?
No inclusion terms are listed for G99 in this reference record. No code-first instruction is listed. No Excludes1 note is listed. No Excludes2 note is listed.