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ICD-10-CM 2027 diagnosis code

I71.01Dissection of thoracic aorta

Not billable — use a more specific code

I71.01 is a header code, so it can't be reported by itself. Choose one of the 4 more specific codes beneath it.

Code last changed in FY2023 (effective October 1, 2022). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About I71.01

I71.01 is the ICD-10-CM diagnosis code for dissection of thoracic aorta. It belongs to category I71 (aortic aneurysm and dissection), block I70-I79 (diseases of arteries, arterioles and capillaries) and chapter 9 (diseases of the circulatory system). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.

Within I71.0 (dissection of aorta), I71.01 is specifically for dissection of thoracic aorta. Related codes cover unspecified site of aorta (I71.00), abdominal aorta (I71.02) and thoracoabdominal aorta (I71.03).

To report this condition, pick the subcode that matches the documentation: I71.010 (aorta), I71.011 (arch), I71.012 (aorta) and I71.019 (unspecified).

Code first , if applicable: syphilitic aortic aneurysm (A52.01) and traumatic aortic aneurysm (S25.09, S35.09).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2023 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 441.01 (dissection of aorta, thoracic).

Specific codes under I71.01

Notes that apply from higher levels

Instructions written at a parent level also apply to I71.01.

› From I71 Aortic aneurysm and dissection
Code first
  • , if applicable:
  • syphilitic aortic aneurysm (A52.01)
  • traumatic aortic aneurysm (S25.09, S35.09)

Broader instructions also apply from Chapter 9: Diseases of the circulatory system.

ICD-9-CM equivalent

Converter →
  • 441.01Dissection of aorta, thoracicexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • FY2023 (effective 10/1/2022): Expanded — no longer billable

Common questions about I71.01

Is I71.01 billable?

No. I71.01 is a header code. Report one of its more specific subcodes instead.

What is the ICD-9 code for I71.01?

The CMS General Equivalence Mappings map I71.01 to ICD-9-CM 441.01.