G99.8
Billable codeOther specified disorders of nervous system in diseases classified elsewhere
The ICD-10 code for other specified disorders of nervous system in diseases classified elsewhere is G99.8.
Clinical notes
Code first
This code represents a manifestation of an underlying disease. Coding convention requires the underlying (etiology) code to be sequenced first, with this code listed second.
Excludes1 (not coded here)
An Excludes1 note is a pure exclusion: the excluded condition and this code should never be reported together, because the two conditions cannot occur at the same time (e.g. a congenital form vs. an acquired form of the same disease).
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •Confirm the excluded condition(s) listed above are not also present — Excludes1 conditions cannot be coded together with this one.
- •This code represents a manifestation. Documentation should identify the underlying condition, which must be coded first.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Related codes in this category
- G99.0Autonomic neuropathy in diseases classified elsewhere
- G99.2Myelopathy in diseases classified elsewhere
- G99.8Other specified disorders of nervous system in diseases classified elsewhere
ICD-9-CM equivalent
Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.
- 34989Approximate match
Associated MS-DRGs
G99.8 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.
Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.