Q26.0
BillableCongenital stenosis of vena cava
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Q26.0 an HCC code?
No. Q26.0 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for Q26.0
For Q26.0to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- 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
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed Q26.0 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
Q26.0 is the ICD-10-CM diagnosis code for congenital stenosis of vena cava. A birth defect where the vena cava (the large vein that returns blood to the heart) is abnormally narrowed, restricting blood flow. Q26.0 sits in the ICD-10-CM chapter for congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (q00-qa0), within the section covering congenital malformations of the circulatory system (q20-q28).
Q26.0 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
This code maps to HCC 191 (Obesity) in the RxHCC model with RAF 0.0, which appears to be an incorrect mapping as this is a congenital vascular condition. The zero RAF weight does not account for potential complex interventional procedures and specialized medications.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Q26.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Specify whether the stenosis affects the superior or inferior vena cava in clinical documentation
- •This condition may require imaging confirmation and should be documented with severity if known
Clinical Significance
Congenital vena cava stenosis can significantly impact venous return to the heart, potentially causing superior or inferior vena cava syndrome with associated complications. This rare condition requires specialized cardiac management and may need surgical intervention.
Documentation Requirements
- ✓Imaging confirmation of vena cava narrowing (echo, CT, MRI)
- ✓Specification of superior vs inferior vena cava involvement
- ✓Assessment of collateral venous circulation
- ✓Clinical signs of vena cava obstruction syndrome
- ✓Associated congenital cardiac anomalies
- ✓Hemodynamic assessment of stenosis severity
- ✓Treatment planning (surgical vs interventional)
- ✓Long-term cardiology and vascular surgery follow-up