ICD-10 Code G91.2 – (Idiopathic) Normal Pressure Hydrocephalus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G91.2 – (Idiopathic) normal pressure hydrocephalus
What it is
G91.2 identifies idiopathic normal pressure hydrocephalus, a form of hydrocephalus with enlarged ventricles and no clear cause. It is used when the condition is documented as idiopathic or normal pressure hydrocephalus.
Clinical signs
Typical findings include gait disturbance, cognitive decline, and urinary incontinence, though not every patient has all three. Clinical features vary; refer to documentation.
When to use this code
Use G91.2 when the provider documents idiopathic normal pressure hydrocephalus or normal pressure hydrocephalus as the diagnosis. Choose it for confirmed cases supported by imaging or specialist assessment. If the record only says hydrocephalus without this specific type, check documentation.
Do not use for
Do not use this code for hydrocephalus with an identified cause, such as obstruction or congenital conditions. Do not use it when the chart does not clearly document normal pressure hydrocephalus.
Coding tip
Confirm the wording “idiopathic” or “normal pressure hydrocephalus” in the assessment before assigning G91.2.