Aortic Aneurysm and Dissection ICD-10-CM codes

The fourth character of I71 identifies the segment and rupture status: I71.0- dissection, I71.1- thoracic ruptured, I71.2- thoracic without rupture, I71.3- abdominal ruptured, I71.4- abdominal without rupture, I71.5- thoracoabdominal ruptured, I71.6- thoracoabdominal without rupture, and I71.8 or I71.9 for an unspecified site. An aneurysm is coded as without rupture unless rupture is documented.

Since FY2022 a fifth character adds the precise location. Thoracic aneurysms are ascending (I71.21), arch (I71.22), or descending (I71.23), with I71.20 for unspecified. Abdominal aneurysms are pararenal (I71.41), juxtarenal (I71.42), or infrarenal (I71.43), with I71.40 for an AAA without further detail. The ruptured codes follow the same pattern (I71.11 to I71.13 and I71.31 to I71.33).

Dissection codes are I71.00 (unspecified site), I71.010 ascending aorta, I71.011 aortic arch, I71.012 descending thoracic aorta, I71.019 thoracic unspecified, I71.02 abdominal, and I71.03 thoracoabdominal. A Stanford type A dissection involves the ascending aorta and maps to I71.010; a type B dissection is confined to the descending aorta and maps to I71.012.

Aortic ectasia (dilation that does not meet the size threshold for aneurysm) is I77.810 (thoracic) or I77.811 (abdominal), not I71. Aortic atherosclerosis documented with the aneurysm is coded separately as I70.0. After endovascular or open repair, report Z95.828 for the graft status and use a T82 complication code for an endoleak or graft failure.