Q07.01 ICD-10-CM Code: Arnold-Chiari syndrome with spina bifida
Q07.01 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
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FY 2026 Apr update / Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0) / Congenital malformations of the nervous system (Q00-Q07)
Q07.01
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceArnold-Chiari syndrome with spina bifida
A birth defect where brain tissue extends into the spinal canal combined with an opening in the spine (spina bifida), causing neurological problems.
Buddy Insight
Arnold-Chiari syndrome with spina bifida represents a complex combination of brain herniation and open spine defects, significantly increasing morbidity and requiring intensive multidisciplinary management.
CMS-HCC V28
MappedHCC 182
Code-level coefficient reference
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
Official- Arnold-Chiari syndrome, type IIInherited from Q07.0
Excludes 2
Official- inborn errors of metabolism (E70-E88)Inherited from Q00-QA0, Q07
- congenital central alveolar hypoventilation syndrome (G47.35)Inherited from Q00-QA0, Q07
- familial dysautonomia [Riley-Day] (G90.1)Inherited from Q00-QA0, Q07
- neurofibromatosis (nonmalignant) (Q85.0-)Inherited from Q00-QA0, Q07
Related Codes
Includes
OfficialNo Includes notes are included in this display for Q07.01. Check the code and parent instructions in the Code Book.
Excludes 1
Official- Arnold-Chiari syndrome, type III (Q01.-)Inherited from Q07.0
- Arnold-Chiari syndrome, type IV (Q04.8)Inherited from Q07.0
Code First
OfficialNo Code First sequencing instructions are included in this display for Q07.01. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for Q07.01. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for Q07.01. 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 Q07.01 an HCC code?
Yes. Q07.01 (Arnold-Chiari syndrome with spina bifida) 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: Q07.01 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
- Q07.01
- Description
- Arnold-Chiari syndrome with spina bifida
- 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 Q07.01 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for Q07.01
For Q07.01, 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
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What This Code Means
Q07.01 is the ICD-10-CM diagnosis code for arnold-chiari syndrome with spina bifida. A birth defect where brain tissue extends into the spinal canal combined with an opening in the spine (spina bifida), causing neurological problems. Q07.01 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, Q07.01 maps to Spinal Cord Disorders/Injuries (HCC 182) with a source-labeled community, non-dual, aged reference coefficient of 0.478. No V24 mapping is shown for Q07.01; use the applicable model and payment year when reviewing the V28 mapping. 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.
Use Q07.01 when the provider wording supports arnold-chiari syndrome with spina bifida. Check the FY2026 tabular notes and the full code path before the final code choice. For Q07.01, 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 Q07.01 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use Q07.01 when the provider wording supports arnold-chiari syndrome with spina bifida. Check the FY2026 tabular notes and the full code path before the final code choice.
- •For this DOS, capture the provider's current assessment and the care action documented for arnold-chiari syndrome with spina bifida. Keep the checklist tied to the note.
- •Do not swap Q07.01 with Q07.00. The FY2026 tabular describes Q07.00 as arnold-chiari syndrome without spina bifida or hydrocephalus. Follow the documented detail.
- •The FY2026 Alphabetic Index routes Arnold-Chiari disease, obstruction or syndrome (type II) with spina bifida to Q07.01. Confirm that the indexed wording matches the provider documentation before using this route.
- •Ask Buddy to show the official notes for Q07.01 or compare its code path with Q07.00.
Clinical Significance
Arnold-Chiari syndrome with spina bifida represents a complex combination of brain herniation and open spine defects, significantly increasing morbidity and requiring intensive multidisciplinary management. This combination often necessitates multiple surgical interventions and lifelong specialized care.
Documentation Requirements
- ✓MRI confirmation of cerebellar tonsillar herniation
- ✓Documentation of concurrent spina bifida
- ✓Neurological deficits from both conditions
- ✓Surgical intervention history for both anomalies
- ✓Current functional status and disabilities
- ✓Associated complications and secondary conditions
- ✓Multidisciplinary care team involvement
- ✓Ongoing monitoring and management plans