2024 ICD-10-CM Diagnosis Code Q04.9

Congenital malformation of brain, unspecified

ICD-10-CM Code:
ICD-10 Code for:
Congenital malformation of brain, unspecified
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Code Navigator:

Code Classification

  • Congenital malformations, deformations and chromosomal abnormalities
    • Congenital malformations of the nervous system
      • Other congenital malformations of brain

Q04.9 is a billable diagnosis code used to specify a medical diagnosis of congenital malformation of brain, unspecified. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024. The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.

Unspecified diagnosis codes like Q04.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Approximate Synonyms

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

  • Anomalies of cerebellum
  • Aplasia cutis congenita secondary to malformation syndrome
  • Bilateral renal hypoplasia
  • Brain malformation, congenital heart disease, postaxial polydactyly syndrome
  • Brain malformations, musculoskeletal abnormalities, facial dysmorphism, intellectual disability syndrome
  • BRESEK syndrome
  • Cerebellar cortical dysplasia
  • Cerebro-costo-mandibular syndrome
  • Cerebrofacioarticular syndrome
  • Choreoathetosis
  • CODAS syndrome
  • Combined malformation of central nervous system and skeletal muscle
  • Congenital anomaly of brain
  • Congenital anomaly of cerebrum
  • Congenital atresia of duodenum
  • Congenital brain damage
  • Congenital corneal dystrophy
  • Congenital hypotrichia
  • Congenital labioscrotal agenesis, cerebellar malformation, corneal dystrophy, facial dysmorphism syndrome
  • Congenital muscular hypertrophy-cerebral syndrome
  • Diplegia
  • Disorder of ornithine metabolism
  • Dysplasia with defective mineralization
  • Early-onset epilepsy, intellectual disability, brain anomalies syndrome
  • Endocrine-cerebro-osteodysplasia syndrome
  • Epilepsy due to congenital anomaly of brain
  • Familial visceral neuropathy
  • Focal epilepsy, intellectual disability, cerebro-cerebellar malformation syndrome
  • Global developmental delay, alopecia, macrocephaly, facial dysmorphism, structural brain anomalies syndrome
  • Hypernatremia
  • Intellectual disability, obesity, brain malformation, facial dysmorphism syndrome
  • Left renal hypoplasia
  • Lethal brain and heart developmental defects syndrome
  • Lethal fetal brain malformation, duodenal atresia, bilateral renal hypoplasia syndrome
  • Leukoencephalopathy, thalamus and brainstem anomalies, high lactate syndrome
  • Linear hypopigmentation and craniofacial asymmetry with acral, ocular and brain anomalies
  • Microcephalus, brain defect, spasticity, hypernatremia syndrome
  • Microphthalmia with brain and digit anomaly
  • Microphthalmos due to Delleman syndrome
  • Mitochondrial DNA depletion syndrome hepatocerebrorenal form
  • Multiple brain anomalies
  • Muscle eye brain disease with bilateral multicystic leukodystrophy
  • Oculocerebrocutaneous syndrome
  • Oculocerebrodental syndrome
  • Oculopalatocerebral syndrome
  • Persistent hyperplastic primary vitreous
  • Right renal hypoplasia
  • Severe oculo-renal-cerebellar syndrome
  • Spastic diplegia
  • Spastic paralysis
  • Visceral neuropathy and brain anomaly with facial dysmorphism and developmental delay syndrome
  • X-linked cerebral, cerebellar, coloboma syndrome

Clinical Classification

Clinical Information

  • Persistent Hyperplastic Primary Vitreous

    a developmental ocular anomaly in which the primary vitreous body and its surrounding hyaloid vasculature failed to regress. it is usually unilateral and characterized by cataract; microphthalmos (small eyeballs), and retrolenticular fibrovascular tissue. (from yanoff: ophthalmology, 2nd ed.)
  • Hypernatremia

    excessive amount of sodium in the blood. (dorland, 27th ed)
  • Brachial Amyotrophic Diplegia|BAD|FAS|Flail Arm Syndrome|MIBS|Man-in-barrel Syndrome

    a neurodegenerative condition characterized by asymmetric weakness in the upper extremities resulting from segmental lower motor neuron dysfunction.
  • Diplegia

    paralysis affecting corresponding parts on both sides of the body.
  • Diplegia of Upper Limbs|Diplegia of upper limbs

    evidence of diplegia of the upper limbs.
  • Neurodevelopmental Disorder with Spastic Diplegia and Visual Defects|MRD19|Mental Retardation, Autosomal Dominant 19|NEDSDV

    an autosomal dominant condition caused by mutation(s) in the ctnnb1 gene, encoding catenin beta-1. it is characterized by severe intellectual disability, progressive spastic diplegia, visual impairment, and dysmorphic craniofacial features.
  • Quadriplegia|Bilateral Diplegia|Bilateral Diplegia|Quadriplegia, unspecified|Tetraplegia

    paralysis of all four limbs.
  • Spastic Diplegia|Little's Disease|Spastic diplegic cerebral palsy

    a type of cerebral palsy characterized by spasticity and hypertonia of the lower extremities bilaterally, particularly the legs, hips, and pelvis; this is the most common (70%) form of cerebral palsy.
  • Codas Syndrome

    a rare syndrome caused by mutations in the lonp1 gene. it is characterized by developmental delay, cerebral, ocular, dental, auricular, and skeletal abnormalities.
  • Grade 1 Hypernatremia, CTCAE|Grade 1 Hypernatremia

    >uln-150 mmol/l
  • Grade 2 Hypernatremia, CTCAE|Grade 2 Hypernatremia

    >150-155 mmol/l; intervention initiated
  • Grade 3 Hypernatremia, CTCAE|Grade 3 Hypernatremia

    >155-160 mmol/l; hospitalization indicated
  • Grade 4 Hypernatremia, CTCAE|Grade 4 Hypernatremia

    >160 mmol/l; life-threatening consequences
  • Grade 5 Hypernatremia, CTCAE|Grade 5 Hypernatremia

  • Hypernatremia

    higher than normal levels of sodium in the circulating blood.
  • Hypernatremia, CTCAE|Hypernatremia|Hypernatremia

    a disorder characterized by laboratory test results that indicate an elevation in the concentration of sodium in the blood.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.

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 References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

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 IndicatorReason 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-CM

  • ICD-9-CM Code: 742.9 - Nervous system anom NOS
    Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education

Brain Malformations

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

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.


[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.