ICD-10 Code G91.3 – Post-traumatic hydrocephalus, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G91.3 – Post-traumatic hydrocephalus, unspecified
What it is
G91.3 identifies hydrocephalus that develops after head trauma, without a more specific subtype documented. Use it when the record states post-traumatic hydrocephalus but does not further define the cause or type.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include symptoms of increased intracranial pressure or neurologic decline after injury, but you should code only what is supported in the chart.
When to use this code
Use G91.3 when the provider documents post-traumatic hydrocephalus as the diagnosis and no additional detail is available. It may appear in follow-up notes after traumatic brain injury, especially when imaging or neurosurgical assessment confirms hydrocephalus.
If the record links hydrocephalus to a prior head injury but does not specify obstructive, communicating, or another type, this unspecified code is appropriate. Check documentation for the traumatic event and any more specific hydrocephalus description.
Do not use for
Do not use this code for congenital, normal pressure, or other non-traumatic hydrocephalus. If the documentation identifies a more specific post-traumatic type, code that instead.
Coding tip
Confirm that the provider explicitly connects hydrocephalus to trauma before assigning G91.3.