Q04.9 Congenital malformation of brain, unspecified

Billable ICD-10-CM code, FY2026. Exempt from present-on-admission (POA) reporting.

Applicable to

• Congenital anomaly NOS of brain
• Congenital deformity NOS of brain
• Congenital disease or lesion NOS of brain
• Multiple anomalies NOS of brain, congenital

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)

• 742.9 Unspecified congenital anomaly of brain, spinal cord, and nervous system (approximate)

Diagnosis Index entries for Q04.9

• Anomaly, anomalous (congenital) (unspecified type) › brain (multiple)
• Anomaly, anomalous (congenital) (unspecified type) › cerebral
• Anomaly, anomalous (congenital) (unspecified type) › dura (brain)
• Cyclencephaly
• Deformity › brain (congenital)
• Deformity › cerebral, acquired › congenital
• Disease, diseased › brain › congenital
• Distortion (s) (congenital) › brain
• Lesion (s) (nontraumatic) › brain › congenital
• Malformation (congenital) › brain (multiple)
• Malformation (congenital) › cerebral
• Malformation (congenital) › dura › brain

Nearby codes

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