Q26.2
BillableTotal anomalous pulmonary venous connection
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Q26.2 an HCC code?
No. Q26.2 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 Q26.2
For Q26.2to 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 Q26.2 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
Q26.2 is the ICD-10-CM diagnosis code for total anomalous pulmonary venous connection. A birth defect where all four pulmonary veins (which should return blood from the lungs to the left side of the heart) abnormally connect to the wrong location, such as the right atrium or vena cava. Q26.2 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).
Q26.2 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 critical congenital heart condition requiring complex surgical intervention. The zero RAF weight significantly understates the high-cost care typically required.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Q26.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a serious congenital heart defect that typically requires surgical correction
- •Document the specific site of connection (supracardiac, cardiac, infracardiac, or mixed) if documented
Clinical Significance
Total anomalous pulmonary venous connection is a critical congenital heart defect requiring immediate surgical correction in infancy due to severe cyanosis and risk of pulmonary venous obstruction. This complex condition has significant impact on long-term cardiac function and survival.
Documentation Requirements
- ✓Echocardiographic confirmation of anomalous pulmonary venous drainage
- ✓Specification of connection type (supracardiac, cardiac, infracardiac, mixed)
- ✓Assessment of pulmonary venous obstruction
- ✓Documentation of cyanosis and oxygen saturation levels
- ✓Associated cardiac anomalies evaluation
- ✓Surgical correction details and timing
- ✓Post-operative complications and outcomes
- ✓Long-term cardiology follow-up requirements
Commonly Confused Codes
- •Q26.3 — Partial anomalous pulmonary venous connection (only some veins affected)
- •Q26.4 — Anomalous pulmonary venous connection, unspecified (type not specified)
- •Q21.2 — Atrioventricular septal defect (different structural anomaly)
- •Q26.8 — Other congenital malformations of great veins (less specific)