G91.0

Communicating hydrocephalus

Risk-adjusting (HCC)Billable code

HCC risk adjustment mapping

CMS-HCC V28

HCC127

Dementia, Mild or Unspecified

CMS-HCC ESRD V24

HCC51

Dementia With Complications

Coding notes

Excludes 1 never coded together · Excludes 2 may co-exist

This code · G91.0

Synonyms

Secondary normal pressure hydrocephalus

Inherited from G91Hydrocephalus

Includes

acquired hydrocephalus

Excludes 1

Arnold-Chiari syndrome with hydrocephalus (Q07.-) congenital hydrocephalus (Q03.-) spina bifida with hydrocephalus (Q05.-)

Inherited from chapter 6Diseases of the nervous system

Excludes 2

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)

Official Guidelines for G91.0

FY 2026 ›

I.C.6Chapter-specific guidanceChapter 6: Diseases of the Nervous System (G00-G99)

Subsections

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