March 4, 2026

Fontan Physiology Complications and ICD-10-CM Coding 

Overview of the Fontan Procedure and Fontan Physiology 

The Fontan procedure (Fontan circulation) is performed in pediatric patients with single-ventricle congenital heart defects such as Tricuspid atresia, Hypoplastic left heart syndrome, and Double outlet right ventricle. 

The altered “Fontan physiology” (chronic venous hypertension and low cardiac output) can result in long-term systemic complications affecting the liver, lymphatic system, and overall circulation. 


ICD-10-CM Coding for Fontan-Associated Conditions 

Use category I27.84- to report complications specific to Fontan physiology: 

  • I27.840 – Fontan-associated liver disease (FALD) 
  • I27.841 – Fontan-associated lymphatic dysfunction 
  • I27.848 – Other Fontan-associated condition 
  • I27.849 – Fontan-related circulation, unspecified 


Coding Guidance 

Code the specific Fontan-associated complication when documented. 


I27.840 (FALD), FALD may include: 

  • Liver fibrosis or cirrhosis 
  • Regenerative arterialized liver nodules 
  • Hepatocellular carcinoma
  • Code additional diagnoses (e.g., cirrhosis, hepatocellular carcinoma) as applicable. 


I27.841 (Lymphatic dysfunction), Manifestations may include: 

  • Plastic bronchitis 
  • Protein-losing enteropathy
    Report additional codes for the specific manifestations when documented.     


I27.848 Other Fontan-associated condition, examples may include: 

  • Arrhythmias 
  • Ventricular dysfunction 
  • Organ fibrosis 


I27.849 Fontan related circulation, unspecified 

  • Use when documentation states “Fontan-related circulation” without further detail. 





Lori Amende, RHIA, CCS 

Education and Quality Manager at UASI


Works Cited 

American Hospital Association. (2025). Fontan-associated complications coding guidance. AHA Coding Clinic for ICD-10-CM/PCS, Fourth Quarter 2025, p. 19. 


Children’s Hospital of Philadelphia. (n.d.). Hypoplastic left heart syndrome (HLHS). Available at: https://www.chop.edu/conditions-diseases/hypoplastic-left-heart-syndrome-hlhs 


Leeds Teaching Hospitals NHS Trust. (n.d.). Fontan circulation. Available at: https://www.leedsth.nhs.uk/patients/resources/fontan-circulation/ 

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