2026 ICD-10-CM Diagnosis Code I71.03Dissection of thoracoabdominal aorta

ICD-10-CM Codes›I00–I99›I70-I79›I71

ICD-10-CM I71.03
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I71.03 is a billable ICD-10-CM diagnosis code for dissection of thoracoabdominal aorta. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 299 through 301. Coders also document this condition as abnormality of thoracoabdominal aorta. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Arterial dissections.

Code Identity

ICD-10-CM Code
I71.03
Billable Status
Yes — Valid for Submission
Code Describes
Dissection of thoracoabdominal aorta
Short Description
Dissection of thoracoabdominal aorta
Same as the full description in the CMS dataset.
Parent Code
I71.0
Dissection of aorta

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI70-I79Diseases of arteries, arterioles and capillaries
CategoryI71Aortic aneurysm and dissection
This CodeI71.03Dissection of thoracoabdominal aorta

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormality of thoracoabdominal aorta
  • Dissection of descending aorta
  • Dissection of thoracoabdominal aorta
  • Type III dissection of descending aorta
  • Type IIIb dissection of descending aorta

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Dissection
      • aorta
        • thoracoabdominal
    • Hematoma(traumatic) (skin surface intact)
      • aorta, dissecting
        • thoracoabdominal

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR CIR027
Arterial dissections
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Aortic Aneurysm

An aneurysm is a bulge or "ballooning" in the wall of an artery. Arteries are blood vessels that carry oxygen-rich blood from the heart to other parts of the body. If an aneurysm grows large, it can burst and cause dangerous bleeding or even death.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert I71.03 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
441.03 Dsct of thoracoabd aorta
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About I71.03Overview

Is I71.03 (Dissection of aorta) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report dissection of thoracoabdominal aorta on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I71.03 group to?

When dissection of thoracoabdominal aorta is the principal diagnosis on an inpatient stay, it groups to MS-DRG 299, 300, 301, with relative weights from 0.7197 to 1.6327 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I71.03?

Under the General Equivalence Mappings, dissection of thoracoabdominal aorta converts to ICD-9-CM 441.03 (dsct of thoracoabd aorta). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.