New ICD-10 Codes Recognize Fontan-Associated Conditions, Advancing Care and Coverage for Rare Congenital Heart Disease Community

SEOUL, South Korea, April 16, 2025 /PRNewswire/ — Mezzion Pharmaceuticals, a global leader in the development of therapies for patients with single ventricle heart disease, announces a transformative milestone for the Fontan community: the introduction of new, dedicated ICD-10 diagnosis codes for Fontan-associated conditions in the U.S. Centers for Medicare & Medicaid Services (CMS) FY 2026 IPPS Proposed Rule.

Listed under Table 6A of the proposed rule, the following new diagnostic codes represent the first-ever formal classification of complications specific to the Fontan circulation:

• 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

These new codes will allow for improved clinical documentation, insurance reimbursement, and health system recognition of the unique and complex needs of patients living with Fontan physiology.

“This is a monumental step forward for the Fontan community,” said Dean Park, Chairman and CEO of Mezzion Pharmaceuticals. “The introduction of ICD-10 codes dedicated to Fontan-associated conditions represents long-overdue validation of the challenges faced by these patients and their families. We applaud the tireless efforts of our advocacy, clinical, and policy partners for making this achievement possible.”

The codes create a new branch within the ICD-10 classification system specific to Fontan physiology. This advancement will help clinicians better track and manage Fontan-related complications, fuel more accurate epidemiological research, and enable public and private payers to recognize Fontan patients as a distinct population with specific medical needs.

For Mezzion, the new codes mark a significant regulatory and commercial milestone in the development of udenafil, a first-in-class therapy under investigation to improve exercise capacity in Fontan patients. Udenafil is currently being evaluated in FUEL-2, a Phase 3 confirmatory trial being conducted across the U.S., Europe, and APAC.

“These codes bring clarity and structure to an area of medicine that has long lacked both. They strengthen the foundation for our continued development and future market access efforts,” added Mr. Park. “As the only company solely focused on this patient population, Mezzion is proud to help lead the charge in advancing recognition, research, and treatment for those living with Fontan circulation.”

The proposed ICD-10 codes are open for public comment through June 10, 2025, with finalization expected by August 2025 and implementation anticipated by September 2025.

About Mezzion Pharmaceuticals, Inc.
Mezzion Pharmaceuticals is dedicated to improving outcomes for patients with rare congenital heart diseases. The company is advancing udenafil, a first-in-class therapy for individuals with Fontan physiology, currently in Phase 3 clinical trials. Learn more at www.Mezzion.com and www.Fuel2Study.com.

Media Contacts:
John Presser, EVP, CBO, john.presser@mezzion.com
Mr. S.I. Noh, CFO, sung-il.noh@mezzion.com

SOURCE: CMS.gov

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SOURCE Mezzion Pharmaceuticals, Inc