ICD-10 Code I51.0 – Cardiac septal defect, acquired (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I51.0 – Cardiac septal defect, acquired
What it is
This code identifies an acquired opening in the cardiac septum, meaning the defect developed after birth rather than being congenital. It is used when documentation describes a septal defect caused by another process.
Clinical signs
Clinical features vary; refer to documentation. Findings may include evidence of abnormal shunting or a septal defect noted on cardiac imaging or surgical assessment.
When to use this code
Use I51.0 when the record clearly states an acquired cardiac septal defect and does not describe a congenital defect. It may apply after trauma, surgery, infection, or another acquired cardiac process, if documented. Check documentation for the cause and anatomy.
Do not use for
Do not use this code for congenital septal defects, such as atrial or ventricular septal defects present at birth. If the defect type or origin is unclear, check documentation before assigning a code.
Coding tip
Verify that “acquired” is explicitly documented, because congenital septal defects are coded elsewhere.