Q02 ICD-10-CM Code: Microcephaly
Q02 maps to CMS-HCC V28 182. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC Buddy coding tools
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0) / Congenital malformations of the nervous system (Q00-Q07)
Q02
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMicrocephaly
A birth defect where the baby's head and brain are smaller than normal, which can affect development and function.
Buddy Insight
Microcephaly represents significantly reduced head and brain size at birth, indicating impaired brain development with high risk for intellectual disability, developmental delays, and neurological complications.
CMS-HCC V28
MappedHCC 182
Coefficient HCC 182: 0.478 (Community Non-Dual Aged (CNA))
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
MappedHCC 114
Code-level coefficient reference
ESRD/PACE
MappedHCC 72
Code-level coefficient reference
RXHCC
MappedHCC 155
Code-level coefficient reference
Code Book Path
Inclusion Terms
OfficialNo inclusion terms are included in this display for Q02. Check the code and parent instructions in the Code Book.
Excludes 2
Official- inborn errors of metabolism (E70-E88)Inherited from Q00-QA0
Related Codes
No related codes are included in this display for Q02. Check the Code Book for the complete code path.
Includes
Official- hydromicrocephaly
- micrencephalon
Excludes 1
Official- Meckel-Gruber syndrome (Q61.9)
Code First
Official- , if applicable, congenital Zika virus disease
Use Additional
OfficialNo Use Additional Code instructions are included in this display for Q02. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for Q02. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is Q02 an HCC code?
Yes. Q02 (Microcephaly) maps to HCC 182, Spinal Cord Disorders/Injuries under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.478. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.
Coder answer: Q02 is billable and maps to V28 HCC 182, Spinal Cord Disorders/Injuries. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- Q02
- Description
- Microcephaly
- HCC (V28)
- HCC 182 — Spinal Cord Disorders/Injuries
- RAF reference coefficient
- 0.478
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.
Work Q02 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for Q02
For Q02, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Coder workflow notes
Get the V28 mapping + MEAT cheat sheet
One printable reference: check representative V28 mappings and the documentation reminders your note needs. Free, no card.
Free PDF. No card. Unsubscribe anytime.
What This Code Means
Q02 is the ICD-10-CM diagnosis code for microcephaly. A birth defect where the baby's head and brain are smaller than normal, which can affect development and function. Q02 sits in the ICD-10-CM chapter for congenital malformations, deformations and chromosomal abnormalities (q00-qa0), within the section covering congenital malformations of the nervous system (q00-q07).
Under the CMS-HCC V28 risk adjustment model, Q02 maps to Spinal Cord Disorders/Injuries (HCC 182) with a source-labeled community, non-dual, aged reference coefficient of 0.478. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.
Document the severity (mild, moderate, severe) if specified in clinical notes. For Q02, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for Q02 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the severity (mild, moderate, severe) if specified in clinical notes
- •Note any associated conditions such as intellectual disability or seizures
Clinical Significance
Microcephaly represents significantly reduced head and brain size at birth, indicating impaired brain development with high risk for intellectual disability, developmental delays, and neurological complications. This diagnosis requires comprehensive evaluation for underlying causes and early intervention services.
Documentation Requirements
- ✓Head circumference measurements below 2-3 standard deviations for gestational age
- ✓Documentation of small brain size on neuroimaging
- ✓Associated dysmorphic features if present
- ✓Maternal history including infections, exposures, genetic factors
- ✓Neurological examination findings
- ✓Genetic testing results if performed
- ✓Developmental assessments and early intervention referrals
- ✓Ophthalmologic and hearing evaluations
Includes
- hydromicrocephaly
- micrencephalon
Excludes 1, Do NOT code together
- Meckel-Gruber syndrome (Q61.9)
Code First
- , if applicable, congenital Zika virus disease