Atherosclerosis of the aorta is a common condition in the elderly and the ICD-9-CM code is 440.0. However, it’s important to distinguish the difference between atherosclerosis of the vessel (which is a risk adjusted diagnosis) and a valve (ICD-9-CM code 424.1, which is not risk adjusted). Where possible and known, the PCP should document the section of the aorta, such as “Atherosclerosis of the abdominal aorta.”

This answer was updated for ICD-10-CM. Read here.