Q04.1 – Arhinencephaly

ICD-10-CM 2027 diagnosis code · Congenital malformations of the nervous system

Billable code

ICD-10-CM code Q04.1

Code: Q04.1 (claims format: Q041)
Description: Arhinencephaly
Billable: Yes – valid for HIPAA-covered transactions
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 17. Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (Q00-QA1)
Block: Q00-Q07 Congenital malformations of the nervous system
Parent codes: Q04

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Q04 – Other congenital malformations of brain

Excludes1 (not coded here):

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

Index terms for Q04.1

Entries in the ICD-10-CM alphabetic index that lead to this code:

Arhinencephaly

Related codes in Q04

Q04.0 – Congenital malformations of corpus callosumBillable
Q04.2 – HoloprosencephalyBillable
Q04.3 – Other reduction deformities of brainBillable
Q04.4 – Septo-optic dysplasia of brainBillable
Q04.5 – MegalencephalyBillable
Q04.6 – Congenital cerebral cystsBillable
Q04.8 – Other specified congenital malformations of brainBillable
Q04.9 – Congenital malformation of brain, unspecifiedBillable

Frequently asked questions

What is ICD-10 code Q04.1?

Q04.1 is the ICD-10-CM code for arhinencephaly, in the block Q00-Q07 (Congenital malformations of the nervous system).

Is Q04.1 a billable code?

Yes. Q04.1 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does Q04.1 belong to?

It belongs to category Q04 – Other congenital malformations of brain.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.