ICD-10-CM 2027
ICD-10 code for brain nondevelopment
From the official ICD-10-CM alphabetic index entry “Nondevelopment › brain”. Page updated September 29, 2026.
About coding brain nondevelopment
The ICD-10-CM code for brain nondevelopment is Q02 (Microcephaly). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on Q02.
Don't report Q02 together with the conditions in its Excludes1 note: Meckel-Gruber syndrome (Q61.9).
Code first: , if applicable, congenital Zika virus disease.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
More specific brain nondevelopment codes (official index)
- part of Q04.3 — Other reduction deformities of brain
Don't confuse with (Excludes1 for Q02)
- Meckel-Gruber syndrome (Q61.9)
Common questions about brain nondevelopment ICD-10 codes
What is the ICD-10 code for brain nondevelopment?
- Q02 — Microcephaly. More specific codes apply when the documentation supports them: Q04.3.
What is the ICD-10 code for part of brain nondevelopment?
- Q04.3 — Other reduction deformities of brain.
Is Q02 billable?
- Yes. Q02 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q02 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q02 as a principal diagnosis.
Is Q02 a CC or MCC?
- No. Q02 is neither a CC nor an MCC under MS-DRG v44.0.