G99

Non-billable

Other disorders of nervous system in diseases classified elsewhere

G99 is the ICD-10-CM code for Other disorders of nervous system in diseases classified elsewhere. It is a non-billable category code — use a more specific child code such as G99.0 for billing.

Status
Header (non-billable)
Chapter
G00-G99
Subcodes
3
Edition
FY2026

G00-G99 Diseases of the nervous system

What this means — in plain language

MedlinePlus · NIH

The brain, spinal cord, and nerves make up the nervous system. Together they control all the workings of the body. When something goes wrong with a part of your nervous system, you can have trouble moving, speaking, swallowing, breathing, or learning. You can also have problems with your memory, senses, or mood. There are more than 600 neurologic diseases. Major types include: Diseases caused by faulty genes, such…

Read more about Neurologic Diseases at MedlinePlus ↗

Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.

No additional coding notes for this code.

Frequently asked questions

What is ICD-10 code G99?
G99 is the ICD-10-CM code for "Other disorders of nervous system in diseases classified elsewhere". It falls under G00-G99 Diseases of the nervous system.
Is G99 a billable code?
No — G99 is a non-billable header code. Use a more specific child code (such as G99.0) for billing.
What are the subcodes of G99?
G99 has 3 more specific child codes, including G99.0, G99.2, G99.8.

Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.

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