Q04.6 Congenital cerebral cysts

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis. Exempt from present-on-admission (POA) reporting.

Applicable to

• Porencephaly
• Schizencephaly

Excludes1 (never code together)

• acquired porencephalic cyst (G93.0)

Applies from Q04 Other congenital malformations of brain

Excludes1 (never code together)

• cyclopia (Q87.0)
• macrocephaly (Q75.3)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 182 — Spinal Cord Disorders/Injuries
• CMS-HCC V22: HCC 72 — Spinal Cord Disorders/Injuries
• RxHCC V08: HCC 155 — Spinal Cord Disorders
• ESRD V24: HCC 72

MS-DRG index

Defines the logic of DRG(s) 091-093 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 742.4 Other specified congenital anomalies of brain (approximate)

Code annotations containing back-references to Q04.6

Back-references to Q04.6

• Type 1 Excludes: G93.0 Cerebral cysts ("congenital cerebral cysts (Q04.6)")

Diagnosis Index entries for Q04.6

• Cyst (colloid) (mucous) (simple) (retention) › arachnoid, brain (acquired) › congenital
• Cyst (colloid) (mucous) (simple) (retention) › brain (acquired) › congenital
• Cyst (colloid) (mucous) (simple) (retention) › brain (acquired) › third ventricle (colloid), congenital
• Cyst (colloid) (mucous) (simple) (retention) › choroid plexus › congenital
• Cyst (colloid) (mucous) (simple) (retention) › paraphysis, cerebri, congenital
• Cyst (colloid) (mucous) (simple) (retention) › porencephalic
• Degeneration, degenerative › brain (cortical) (progressive) › cystic › congenital
• Porencephaly (congenital) (developmental) (true)
• Schizencephaly

Nearby codes

• Q04.1 Arhinencephaly
• Q04.2 Holoprosencephaly
• Q04.3 Other reduction deformities of brain
• Q04.4 Septo-optic dysplasia of brain
• Q04.5 Megalencephaly
• Q04.6 Congenital cerebral cysts (this code)
• Q04.8 Other specified congenital malformations of brain
• Q04.9 Congenital malformation of brain, unspecified