G91 ICD-10-CA category: Hydrocephalus
G91 isn’t a code on its own. Choose one of the 6 codes beneath it, the one the documentation supports.
Official description
G91Hydrocephalus
ICD-10-CA · Canada
Codes in G91
G91 isn’t a code on its own. Open the code that matches what the note documents.
Notes for G91
As CIHI prints them, with any note G91 takes from the headings above it.
Includes
- Acquired hydrocephalus
Excludes
Conditions classified elsewhere.
- Hydrocephalus:• acquired, of newborn (P91.7)• congenital (Q03.-)• due to congenital toxoplasmosis (P37.1)
- Certain:• conditions originating in the perinatal period (P00-P96)• infectious and parasitic diseases (A00-B99)complications of pregnancy, childbirth and the puerperium (O00-O99)congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E90)injury, poisoning and certain other consequences of external causes (S00-T98)neoplasms (C00-D48)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)From Chapter 6: Diseases of the nervous system (G00-G99)
Where G91 sits
- 1ChapterChapter 6: Diseases of the nervous system (G00-G99)
- 2Block G90-G99Other disorders of the nervous system
- 3Category G91Hydrocephalus
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
Is G91 a valid ICD-10-CA code?
No. G91 (Hydrocephalus) is a category heading in CIHI’s ICD-10-CA FY 2026–2027 release. It holds 6 codes; record the one the documentation supports.
Where is G91 in ICD-10-CA?
G91 sits under G90-G99 Other disorders of the nervous system, within Chapter 6: Diseases of the nervous system (G00-G99).
What coding notes apply to G91?
ICD-10-CA lists Includes, Excludes notes for G91, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.
Codes beside G91
View G90-G99G90Disorders of autonomic nervous systemG92Toxic encephalopathyG93Other disorders of brainG94Other disorders of brain in diseases classified elsewhereG95Other diseases of spinal cordG96Other disorders of central nervous systemG97Postprocedural disorders of nervous system, not elsewhere classifiedG98Other disorders of nervous system, not elsewhere classifiedG99Other disorders of nervous system in diseases classified elsewhere