ICD-10-CM · Chapter 6 · G00-G99
G91 Hydrocephalus
Includes
- acquired hydrocephalus
Excludes 1 (cannot be coded together)
- Arnold-Chiari syndrome with hydrocephalus (Q07.-)
- congenital hydrocephalus (Q03.-)
- spina bifida with hydrocephalus (Q05.-)
Subcodes
Each subcode links to a detail page with full clinical annotations.
| Code | Description | Billable |
|---|---|---|
| G91..0 | Communicating hydrocephalus | Yes |
| G91..1 | Obstructive hydrocephalus | Yes |
| G91..2 | (Idiopathic) normal pressure hydrocephalus | Yes |
| G91..3 | Post-traumatic hydrocephalus, unspecified | Yes |
| G91..4 | Hydrocephalus in diseases classified elsewhere | Yes |
| G91..8 | Other hydrocephalus | Yes |
| G91..9 | Hydrocephalus, unspecified | Yes |
Last reviewed: September 2026