G91

Hydrocephalus

Diagnosis reference

Nonbillable category

This entry is a category or subcategory. Choose the appropriate billable descendant based on the clinical documentation.

Effective periodOctober 1, 2026–September 30, 2027

SourceCMS ICD-10-CM order file

ClassificationDiagnosis · clinical modification

Related entries

Up to 30 descendants in this category

CODE	DESCRIPTION	TYPE
G91.0	Communicating hydrocephalus	Billable
G91.1	Obstructive hydrocephalus	Billable
G91.2	(Idiopathic) normal pressure hydrocephalus	Billable
G91.3	Post-traumatic hydrocephalus, unspecified	Billable
G91.4	Hydrocephalus in diseases classified elsewhere	Billable
G91.8	Other hydrocephalus	Billable
G91.9	Hydrocephalus, unspecified	Billable

Use the complete reference

This reference does not reproduce the full tabular hierarchy, inclusion notes, Excludes1/2 notes, sequencing instructions, or seventh-character rules. Review the official tables and coding guidelines.

Open official CMS files

ICD-10-CM codes describe diagnoses. They do not have an independent Medicare PFS reimbursement amount, and billability alone does not establish coverage.