ICD-10-CM Code Q04.9

Congenital malformation of brain, unspecified

Version 2021 Billable Code POA Exempt

Valid for Submission

Q04.9 is a billable code used to specify a medical diagnosis of congenital malformation of brain, unspecified. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code Q04.9 might also be used to specify conditions or terms like agenesis of corpus callosum, anomalies of cerebellum, aplasia cutis congenita secondary to malformation syndrome , brain malformation, congenital heart disease, postaxial polydactyly syndrome, bresek syndrome, cerebellar cortical dysplasia, etc The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.

Short Description:Congenital malformation of brain, unspecified
Long Description:Congenital malformation of brain, unspecified

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code Q04.9:

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Congenital anomaly NOS of brain
  • Congenital deformity NOS of brain
  • Congenital disease or lesion NOS of brain
  • Multiple anomalies NOS of brain, congenital

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code Q04.9 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Agenesis of corpus callosum
  • Anomalies of cerebellum
  • Aplasia cutis congenita secondary to malformation syndrome
  • Brain malformation, congenital heart disease, postaxial polydactyly syndrome
  • BRESEK syndrome
  • Cerebellar cortical dysplasia
  • Cerebro-costo-mandibular syndrome
  • Cerebrofacioarticular syndrome
  • CODAS syndrome
  • Combined malformation of central nervous system and skeletal muscle
  • Congenital anomaly of brain
  • Congenital anomaly of cerebrum
  • Congenital brain damage
  • Congenital muscular hypertrophy-cerebral syndrome
  • Endocrine-cerebro-osteodysplasia syndrome
  • Familial visceral neuropathy
  • Focal epilepsy, intellectual disability, cerebro-cerebellar malformation syndrome
  • Hypernatremia
  • Intellectual disability, obesity, brain malformation, facial dysmorphism syndrome
  • Leukoencephalopathy, thalamus and brainstem anomalies, high lactate syndrome
  • Microcephalus, brain defect, spasticity, hypernatremia syndrome
  • Microphthalmia with brain and digit anomaly
  • Mitochondrial DNA depletion syndrome hepatocerebrorenal form
  • Multiple brain anomalies
  • Muscle eye brain disease with bilateral multicystic leukodystrophy
  • Oculo-cerebro-cutaneous syndrome
  • Oculopalatocerebral syndrome
  • Persistent hyperplastic primary vitreous
  • Persistent primary vitreous
  • Visceral neuropathy and brain anomaly with facial dysmorphism and developmental delay syndrome
  • X-linked cerebral, cerebellar, coloboma syndrome

Present on Admission (POA)

Q04.9 is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here .

CMS POA Indicator Options and Definitions
POA Indicator CodePOA Reason for CodeCMS will pay the CC/MCC DRG?
YDiagnosis was present at time of inpatient admission.YES
NDiagnosis was not present at time of inpatient admission.NO
UDocumentation insufficient to determine if the condition was present at the time of inpatient admission.NO
WClinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.YES
1Unreported/Not used - Exempt from POA reporting. NO

Convert Q04.9 to ICD-9

  • 742.9 - Nervous system anom NOS (Approximate Flag)

Code Classification

  • Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
    • Congenital malformations of the nervous system (Q00-Q07)
      • Other congenital malformations of brain (Q04)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Brain Malformations

Also called: Cephalic disorders

Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it to develop abnormally. Sometimes it's a genetic problem. In other cases, exposure to certain medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, abnormally small or large, or not fully developed.

Treatment depends upon the problem. In many cases, treatment only helps with symptoms. It may include antiseizure medicines, shunts to drain fluid from the brain, and physical therapy.

There are head malformations that do not involve the brain. Craniofacial disorders are the result of abnormal growth of soft tissue and bones in the face and head. It's common for new babies to have slightly uneven heads, but parents should watch the shape of their baby's head for possible problems.

NIH: National Institute of Neurological Disorders and Stroke

  • Brain surgery (Medical Encyclopedia)
  • Brain surgery - discharge (Medical Encyclopedia)

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