Q26.8 Other congenital malformations of great veins

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis. Exempt from present-on-admission (POA) reporting.

Applicable to

• Absence of vena cava (inferior) (superior)
• Azygos continuation of inferior vena cava
• Persistent left posterior cardinal vein
• Scimitar syndrome

Risk adjustment (HCC)

• RxHCC V08: HCC 191 — Ventricular Septal Defect and Major Congenital Heart Disorders

MS-DRG index

Defines the logic of DRG(s) 306-307 in MDC 05.

Approximate ICD-9-CM (GEMs)

• 747.49 Other anomalies of great veins (approximate)

Code annotations containing back-references to Q26.8

Back-references to Q26

• Code Also: I27.21 Secondary pulmonary arterial hypertension ("congenital heart disease (Q20-Q28)")
• Type 2 Excludes: P29 Cardiovascular disorders originating in the perinatal period ("congenital malformations of the circulatory system (Q20-Q28)")
• Code Also: Z71.87 Encounter for pediatric-to-adult transition counseling ("congenital malformations of the circulatory system (Q20-Q28)")

Diagnosis Index entries for Q26.8

• Absence (of) (organ or part) (complete or partial) › superior vena cava, congenital
• Absence (of) (organ or part) (complete or partial) › vein (peripheral) congenital NEC › great
• Absence (of) (organ or part) (complete or partial) › vena cava (inferior) (superior), congenital
• Agenesis › vein (s) (peripheral) › great NEC
• Agenesis › vena cava (inferior) (superior)
• Anomaly, anomalous (congenital) (unspecified type) › vein (s) (peripheral) › great › specified NEC
• Anomaly, anomalous (congenital) (unspecified type) › venous return
• Atresia, atretic › vein NEC › great
• Atresia, atretic › vena cava (inferior) (superior)
• Azygos › continuation inferior vena cava
• Hypoplasia, hypoplastic › vein (s) (peripheral) › great
• Hypoplasia, hypoplastic › vena cava (inferior) (superior)
• Malformation (congenital) › great › vein › specified type NEC
• Malposition › congenital › vein (s) (peripheral) › great
• Malposition › congenital › vena cava (inferior) (superior)
• Persistence, persistent (congenital) › left › posterior cardinal vein
• Persistence, persistent (congenital) › sinus › venosus with imperfect incorporation in right auricle
• Scimitar syndrome
• Syndrome › scimitar

Nearby codes

• Q26.2 Total anomalous pulmonary venous connection
• Q26.3 Partial anomalous pulmonary venous connection
• Q26.4 Anomalous pulmonary venous connection, unspecified
• Q26.5 Anomalous portal venous connection
• Q26.6 Portal vein-hepatic artery fistula
• Q26.8 Other congenital malformations of great veins (this code)
• Q26.9 Congenital malformation of great vein, unspecified