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ICD-10-CM 2027 diagnosis code

Q02Microcephaly

✓ Billable / specificPOA exempt

Q02 is a valid, billable ICD-10-CM code for microcephaly. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About Q02

Q02 is the ICD-10-CM diagnosis code for microcephaly. It belongs to block Q00-Q07 (congenital malformations of the nervous system) and chapter 17 (congenital malformations, deformations, chromosomal abnormalities, and genetic disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

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.

In MS-DRG v44.0, it is part of the grouping logic for DRG 091 (Other Disorders of Nervous System with MCC, relative weight 1.7046), DRG 092 (Other Disorders of Nervous System with CC, relative weight 1.0239), DRG 093 (Other Disorders of Nervous System without CC/MCC, relative weight 0.7783), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 01 (Diseases and Disorders of the Nervous System) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 742.1 (Microcephalus).

Coding notes

IncludesFurther defines the content of the category
  • hydromicrocephaly
  • micrencephalon
Excludes1Not coded here — never report together with this code
  • Meckel-Gruber syndrome (Q61.9)
Code firstSequence the underlying condition first
  • , if applicable, congenital Zika virus disease

Notes that apply from higher levels

Instructions written at a parent level also apply to Q02.

Alphabetic index entries

19 entries

Terms in the official ICD-10-CM index that lead to Q02.

Codes whose notes reference Q02

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period

MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period

ICD-9-CM equivalent

Converter →

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about Q02

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.

What DRG does Q02 group to?

Q02 is used in the MS-DRG v44.0 logic for MS-DRG 091 (Other Disorders of Nervous System with MCC), MS-DRG 092 (Other Disorders of Nervous System with CC), MS-DRG 093 (Other Disorders of Nervous System without CC/MCC), MS-DRG 791 (Prematurity with Major Problems) and MS-DRG 793 (Full Term Neonate with Major Problems). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for Q02?

The CMS General Equivalence Mappings map Q02 to ICD-9-CM 742.1.