All ICD10 Codes

G91

Non-Billable
ChapterG00–G99
Rankcategory
Description

Hydrocephalus

About ICD-10-CM code G91

Under G00-G99 Diseases of the Nervous System, within Other disorders of the nervous system (G89-G99), ICD-10-CM code G91 describes Hydrocephalus. This code cannot be billed directly because more specific child codes exist beneath it.

Use a more specific code (7 billable)
G91.0Communicating hydrocephalusG91.1Obstructive hydrocephalusG91.2(Idiopathic) normal pressure hydrocephalusG91.3Post-traumatic hydrocephalus, unspecifiedG91.4Hydrocephalus in diseases classified elsewhereG91.8Other hydrocephalusG91.9Hydrocephalus, unspecified
Metadata & Insights
  • •Non-billable category (requires more specific sub-code).
  • •Chapter 6: Diseases of the Nervous System (G00-G99).

CH6 Parent Instructions

Excludes2(Not included here. Code separately if applicable.)
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Instructional Notes

Includes
  • acquired hydrocephalus
Excludes1(Not coded here. Use a different code.)
  • Arnold-Chiari syndrome with hydrocephalus (Q07.-)
  • congenital hydrocephalus (Q03.-)
  • spina bifida with hydrocephalus (Q05.-)

Clinical Hierarchy

BillableHas subcodes
CH6Diseases of the nervous system (G00-G99)
G89-G99Other disorders of the nervous system (G89-G99)
G91HydrocephalusNot billable
G91.0Communicating hydrocephalusBillable
G91.1Obstructive hydrocephalusBillable
G91.2(Idiopathic) normal pressure hydrocephalusBillable
G91.3Post-traumatic hydrocephalus, unspecifiedBillable
G91.4Hydrocephalus in diseases classified elsewhereBillable
G91.8Other hydrocephalusBillable
G91.9Hydrocephalus, unspecifiedBillable

Applicable Ancestor Context

The following parent sections contain instructions or notes that apply to G91:

chapterCH6
Diseases of the nervous system (G00-G99)
View context instructions

MS-DRG Classification

2026

No direct MS-DRG triggers identified.

Cross Reference

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