G91.9
BillableHydrocephalus, unspecified
HCC Category Mapping
V28HCC 127 — Dementia, Mild or Unspecified
0.464What This Code Means
A condition where excess fluid accumulates in the brain, but the specific type or cause has not been determined or documented.
Coding Tips
- •This is a non-specific code; attempt to obtain more detailed documentation to assign a more specific G91 code
- •Query the provider if additional clinical information is available to clarify the type of hydrocephalus
Clinical Significance
Hydrocephalus, unspecified is used when hydrocephalus is documented but the specific type cannot be determined from the available clinical information. While this code still carries significant risk adjustment value, it represents an opportunity for improved documentation specificity. Coders should query providers when possible to capture a more specific hydrocephalus diagnosis.
Documentation Requirements
- ✓Documentation of hydrocephalus diagnosis, even if type is not further specified
- ✓Imaging evidence of ventricular enlargement
- ✓Clinical symptoms attributable to hydrocephalus
- ✓Any available information about etiology or type that could support a more specific code
- ✓Current management plan including monitoring, medical therapy, or surgical intervention
Commonly Confused Codes
G91.0 — Communicating hydrocephalus: use when CSF absorption impairment without obstruction is documentedG91.1 — Obstructive hydrocephalus: use when a physical blockage of CSF flow is identifiedG91.2 — Normal pressure hydrocephalus: use when the classic triad with normal CSF pressure is documentedQ03.9 — Congenital hydrocephalus, unspecified: use for hydrocephalus present at birth or due to congenital malformation