Pathology/Lab Coding Alert

Specify thoracic or abdominal site

Good news: Nothing changes but the number when you’re reporting aorta dilation under ICD-10 instead of ICD-9. 

You should expect the code-set change this year on Oct. 1, and we’ll help make sure you’re ready for your lab’s diagnosis reporting.

Use Fifth Digit to Designate Site

Currently, when your lab receives an order for a test related to aortic dissection (dilation), you should expect one of the following codes to describe the condition:

• 441.00 — Dissection of aorta, unspecified site 
• 441.01 — Dissection of aorta, thoracic 
• 441.02 — Dissection of aorta, abdominal 
• 441.03 — Dissection of aorta, thoracoabdominal 

Once ICD-10 goes into effect, you’ll see the following codes, which represent a direct, one-to-one crosswalk from ICD-9:

• I71.00 — Dissection of unspecified site of aorta
• I71.01 — Dissection of thoracic aorta
• I71.02 — Dissection of abdominal aorta
• I71.03 — Dissection of thoracoabdominal aorta

Notice: Using either ICD-9 or ICD-10, reporting the four digit code (441.0 or 171.0) would be incorrect. If the documentation doesn’t adequately specify the location of the abnormality, you should not truncate to a four digit code, but instead use the five-digit code for “unspecified site.”