ICD-10 Code I27.84 – Fontan Related Circulation (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I27.84 – Fontan related circulation
What it is
I27.84 identifies Fontan related circulation, a unique circulatory state after a Fontan procedure for single-ventricle congenital heart disease. Use it when documentation specifically describes Fontan physiology or Fontan circulation.
Clinical signs
Clinical features vary; refer to documentation. Patients may have findings consistent with Fontan physiology, such as chronic cyanosis, exercise intolerance, edema, or other signs of circulatory congestion.
When to use this code
Use this code when the provider documents Fontan related circulation, Fontan physiology, or Fontan circulation as the condition being addressed. It may appear in follow-up notes, problem lists, or congenital heart disease assessments. Code it only when the record clearly ties the patient to the post-Fontan circulation state.
Do not use for
Do not use this code for general congenital heart disease without Fontan circulation, or for a history of cardiac surgery alone. Check documentation if the note only mentions a Fontan procedure without current Fontan related circulation.
Coding tip
Look for the exact phrase “Fontan related circulation” or equivalent wording in the assessment before assigning I27.84.