Q04.8
Other specified congenital malformations of brain
Risk-adjusting (HCC)Billable code
HCC risk adjustment mapping
CMS-HCC V28
HCC182
Spinal Cord Disorders/Injuries
CMS-HCC ESRD V24
HCC72
Spinal Cord Disorders/Injuries
RxHCC V08
RXHCC155
Spinal Cord Disorders
Coding notes
Excludes 1 never coded together · Excludes 2 may co-exist
This code · Q04.8
Synonyms
Arnold-Chiari syndrome, type IV Macrogyria
Inherited from Q04Other congenital malformations of brain
Inherited from chapter 17Congenital malformations, deformations and chromosomal abnormalities
Excludes 2
inborn errors of metabolism (E70-E88)
Note
Codes from this chapter are not for use on maternal records
Official Guidelines for Q04.8
FY 2026 ›Sections that reference Q04.8
Sections whose FY 2026 text names Q04.8, its Q04 category, or a range containing it — the chapter guidance above is the authoritative source.
Find Q04.8 in the alphabetic index
16 index paths lead to this code
- Macrogyria
- Ulegyria
- Arnold-Chiari disease, obstruction or syndrome › type IV
- Displacement, displaced › brain stem, caudal
- Displacement, displaced › cerebellum, caudal
- Distortion › gyri
- Ectopic, ectopia › brain
- Ectopic, ectopia › cerebral
- Heterotopia, heterotopic › cerebralis
- Anomaly, anomalous › meninges › cerebral
- Deformity › meninges or membrane › cerebral
- Dilatation › ventricular, ventricle › cerebral, congenital
- Malformation › brain › specified type NEC
- Malformation › meninges or membrane › cerebral
- Malposition › congenital › brain tissue
- Softening › brain › congenital