ICD-10 Code I77.812 – Thoracoabdominal aortic ectasia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I77.812 – Thoracoabdominal aortic ectasia
What it is
Thoracoabdominal aortic ectasia means abnormal widening of the thoracic and abdominal aorta without clear aneurysmal dilation. Use this code when documentation describes diffuse aortic enlargement or ectatic change.
Clinical signs
Clinical features vary; refer to documentation. Imaging may note a mildly enlarged, elongated, or diffusely widened thoracoabdominal aorta without focal aneurysm or dissection.
When to use this code
Use I77.812 when the provider documents thoracoabdominal aortic ectasia, aortic ectasia involving both chest and abdominal segments, or similar wording. It is appropriate when imaging confirms ectatic dilation and the record does not support aneurysm, dissection, or another more specific aortic disorder.
Do not use for
Do not use this code for thoracic aortic aneurysm, abdominal aortic aneurysm, or aortic dissection. Check documentation if the report uses only “aortic enlargement” without specifying ectasia.
Coding tip
Code the most specific aortic diagnosis documented and confirm the anatomic segment before assigning I77.812.