ICD-10/Q04.5

Q04.5 ICD 2026 Code: Megalencephaly

Q04.5 is the authoritative medical code for Megalencephaly. This classification is used in medical billing and clinical recording to specify the clinical criteria for megalencephaly (ICD-10-CM Q04.5), ensuring healthcare documentation aligns with 2026 federal coding standards.

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Official Registry Overview & Definition

Megalencephaly is a billable ICD-10-CM diagnosis code Q04.5. Excludes1 (not coded here): cyclopia Q87.0; macrocephaly Q75.3.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for Q04.5 in the official ICD-10-CM tabular list.

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • cyclopia Q87.0
  • macrocephaly Q75.3

Frequently Asked Questions (FAQ) & Clinical Guidance

What can't be coded together with Q04.5?

Per Excludes1 instructions, Q04.5 must not be reported with: cyclopia (Q87.0); macrocephaly (Q75.3).

Codes in This Family (9)

Official ICD-10-CM classifications in the same code family as Q04.5, with their registry titles.

  • Q04 — Other congenital malformations of brain
  • Q04.0 — Congenital malformations of corpus callosum
  • Q04.1 — Arhinencephaly
  • Q04.2 — Holoprosencephaly
  • Q04.3 — Other reduction deformities of brain
  • Q04.4 — Septo-optic dysplasia of brain
  • Q04.6 — Congenital cerebral cysts
  • Q04.8 — Other specified congenital malformations of brain
  • Q04.9 — Congenital malformation of brain, unspecified

Indexed Clinical Terms (2)

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.

  • Hemimegalencephaly
  • Megalencephaly

Related Codes & Numerical Sequence (Crawl Map)

Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:

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