2026 ICD-10-CM Diagnosis Code I71.9Aortic aneurysm of unspecified site, without rupture

ICD-10-CM Codes›I00–I99›I70-I79›I71

ICD-10-CM I71.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I71.9 is a billable ICD-10-CM diagnosis code for aortic aneurysm of unspecified site, without rupture. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Aortic; peripheral; and visceral artery aneurysms.

Code Identity

ICD-10-CM Code
I71.9
Billable Status
Yes — Valid for Submission
Code Describes
Aortic aneurysm of unspecified site, without rupture
Short Description
Aortic aneurysm of unspecified site, without rupture
Same as the full description in the CMS dataset.
Parent Code
I71
Aortic aneurysm and dissection

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI70-I79Diseases of arteries, arterioles and capillaries
CategoryI71Aortic aneurysm and dissection
This CodeI71.9Aortic aneurysm of unspecified site, without rupture

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Aneurysm of aorta at coarctation site following procedure
  • Aneurysm of descending aorta
  • Aortic aneurysm
  • Aortic aneurysm due to congenital heart disease
  • Aortic aneurysm due to Loeys-Dietz syndrome
  • Aortic left ventricular tunnel
  • Aortic tunnel
  • Aortico-left ventricular tunnel with extracardiac aneurysm of aortic wall
  • Congenital aneurysm of aorta
  • Congenital dilatation of aorta
  • False aneurysm of artery
  • Hyaline necrosis of aorta
  • Necrosis of artery
  • Penetrating ulcer of aorta
  • Pericarditis secondary to aortic aneurysm
  • Post-procedural aortic aneurysm
  • Post-procedural false aortic aneurysm
  • Ulcer of artery

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Aneurysm of aorta
  • Dilatation of aorta
  • Hyaline necrosis of 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.

    • Aneurysm(anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)
      • aorta, aortic (nonsyphilitic)
    • Aneurysm(anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)
      • aorta, aortic (nonsyphilitic)
        • arteriosclerotic
    • Aneurysm(anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)
      • aorta, aortic (nonsyphilitic)
        • descending
    • Aneurysm(anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)
      • cylindroid (aorta)
    • Disease, diseased
      • Fernels' (aortic aneurysm)
    • Fernell's disease(aortic aneurysm)

Clinical ClassificationClinical

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

CCSR CIR029
Aortic; peripheral; and visceral artery aneurysms
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Aneurysm, Ascending Aorta

    an abnormal balloon- or sac-like dilatation in the wall of the ascending aorta.

  • Aortic Aneurysm

    an abnormal balloon- or sac-like dilatation in the wall of aorta.

  • Aortic Aneurysm, Abdominal

    an abnormal balloon- or sac-like dilatation in the wall of the abdominal aorta which gives rise to the visceral, the parietal, and the terminal (iliac) branches below the aortic hiatus at the diaphragm.

  • Aortic Aneurysm, Thoracic

    an abnormal balloon- or sac-like dilatation in the wall of the thoracic aorta. this proximal descending portion of aorta gives rise to the visceral and the parietal branches above the aortic hiatus at the diaphragm.

  • Aortic Aneurysm, Thoracoabdominal

    an abnormal balloon- or sac-like dilatation in the wall of abdominal aorta at the aortic hiatus.

  • Aortic Rupture

    the tearing or bursting of the wall along any portion of the aorta, such as thoracic or abdominal. it may result from the rupture of an aneurysm or it may be due to trauma.

  • Aorta

    the main trunk of the systemic arteries.

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 I71.9 to ICD-9-CMHistory

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

ICD-9-CM
441.9 Aortic aneurysm NOS
Approximate The match is approximate rather than exact.

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 I71.9Overview

Is I71.9 (Aortic aneurysm and dissection) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report aortic aneurysm of unspecified site, without rupture on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I71.9 group to?

When aortic aneurysm of unspecified site, without rupture 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 I71.9?

Under the General Equivalence Mappings, aortic aneurysm of unspecified site, without rupture converts to ICD-9-CM 441.9 (aortic aneurysm NOS). The mapping is approximate, so confirm the match fits the documentation.

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.