2026 ICD-10-CM Diagnosis Code I28.1Aneurysm of pulmonary artery

ICD-10-CM Codes›I00–I99›I26-I28›I28

ICD-10-CM I28.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I28.1 is a billable ICD-10-CM diagnosis code for aneurysm of pulmonary artery. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pulmonary heart disease.

Code Identity

ICD-10-CM Code
I28.1
Billable Status
Yes — Valid for Submission
Code Describes
Aneurysm of pulmonary artery
Short Description
Aneurysm of pulmonary artery
Same as the full description in the CMS dataset.
Parent Code
I28
Other diseases of pulmonary vessels

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI26-I28Pulmonary heart disease and diseases of pulmonary circulation
CategoryI28Other diseases of pulmonary vessels
This CodeI28.1Aneurysm of pulmonary artery

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired aneurysm of pulmonary artery
  • Acquired dissection of pulmonary artery
  • Dilatation of pulmonary artery
  • Injury of pulmonary artery
  • Perforation of pulmonary artery co-occurrent and due to aneurysm of pulmonary artery
  • Peripheral pulmonary artery A/V aneurysm
  • Pulmonary artery aneurysm
  • Pulmonary artery rupture
  • Pulmonary blood vessel injury
  • Pulmonary trunk dilatation
  • Rupture of pulmonary artery co-occurrent and due to aneurysm of pulmonary artery
  • Rupture of pulmonary vessel

Tabular List NotesGuidance

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

Type 1 Excludes

  • congenital aneurysm Q25.79
  • congenital arteriovenous aneurysm Q25.72

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)
      • lung (pulmonary artery)
    • Aneurysm(anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)
      • pulmonary

Clinical ClassificationClinical

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

CCSR CIR014
Pulmonary heart disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Aneurysms

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 I28.1 to ICD-9-CMHistory

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

ICD-9-CM
417.1 Pulmon artery aneurysm
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 I28.1Overview

Is I28.1 (Other diseases of pulmonary vessels) a billable code?

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

What MS-DRG does I28.1 group to?

When aneurysm of pulmonary artery is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I28.1?

Under the General Equivalence Mappings, aneurysm of pulmonary artery converts to ICD-9-CM 417.1 (pulmon artery aneurysm). 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.