2027 ICD-10-CM Diagnosis Code I72.6Aneurysm of vertebral artery

ICD-10-CM Codes›I00–I99›I70-I79›I72

ICD-10-CM I72.6
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I72.6 is a billable ICD-10-CM diagnosis code for aneurysm of vertebral artery. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 299 through 301. Coders also document this condition as aneurysm of left vertebral artery. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Aortic; peripheral; and visceral artery aneurysms.

I72.6 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 108 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 108, ESRD (V21) category 108, and ESRD (V24) category 108 for payment year 2027.

Code Identity

ICD-10-CM Code
I72.6
Billable Status
Yes — Valid for Submission
Code Describes
Aneurysm of vertebral artery
Short Description
Aneurysm of vertebral artery
Same as the full description in the CMS dataset.
Parent Code
I72
Other aneurysm

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI70-I79Diseases of arteries, arterioles and capillaries
CategoryI72Other aneurysm
This CodeI72.6Aneurysm of vertebral artery

Medicare Risk Adjustment (HCC)Billing

I72.6 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 108
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 108 · ESRD (V21): HCC 108 · ESRD (V24): HCC 108
ESRD V21 weights: 0.065 dialysis, 0.086–0.271 functioning graft · ESRD V24 weights: 0.073 dialysis, 0.074–0.287 functioning graft
Part D (RxHCC)
Not mapped
I72.6 does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Aneurysm of left vertebral artery
  • Aneurysm of right vertebral artery
  • False aneurysm of artery
  • Pseudoaneurysm of vertebral artery
  • Ruptured aneurysm of vertebral artery
  • Subarachnoid hemorrhage due to ruptured aneurysm
  • Subarachnoid hemorrhage from vertebral artery aneurysm
  • Vertebral artery aneurysm
  • Vertebral artery rupture

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I72.6: its own notes plus those printed at I72 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From I72 Other aneurysm applies to 9 codes
  • aneurysm (cirsoid) (false) (ruptured)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

On I72.6 itself
  • dissection of vertebral artery (I77.74)
From I72 Other aneurysm applies to 9 codes
  • acquired aneurysm (I77.0)
  • aneurysm (of) aorta (I71.-)
  • aneurysm (of) arteriovenous NOS (Q27.3-)
  • carotid artery dissection (I77.71)
  • cerebral (nonruptured) aneurysm (I67.1)
  • coronary aneurysm (I25.4)
  • coronary artery dissection (I25.42)
  • dissection of artery NEC (I77.79)
  • dissection of precerebral artery, congenital (nonruptured) (Q28.1)
  • heart aneurysm (I25.3)
  • iliac artery dissection (I77.72)
  • precerebral artery, congential (nonruptured) (Q28.1)
  • pulmonary artery aneurysm (I28.1)
  • renal artery dissection (I77.73)
  • retinal aneurysm (H35.0)
  • ruptured cerebral aneurysm (I60.7)
  • varicose aneurysm (I77.0)
  • vertebral artery dissection (I77.74)
From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I72.6, its category, or a range that includes it.

Excludes2 3

These codes carry an Excludes2 note naming I72.6: its condition is not part of those codes, and both may be reported when the patient has both.

  • I72.5 Aneurysm of other precerebral arteries
    aneurysm of vertebral artery (I72.6)
  • I77.74 Dissection of vertebral artery
    aneurysm of vertebral artery (I72.6)
  • I77.75 Dissection of other precerebral arteries
    aneurysm of vertebral artery (I72.6)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

  • Vertebral Artery Aneurysm

    aneurysm of the vertebral artery.

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 I72.6 to ICD-9-CMHistory

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

ICD-9-CM
442.81 Aneurysm of neck
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement I72.6 replaces the following previously assigned code(s):

  • I72.8 - Aneurysm of other specified arteries
FY 2019AddedAdded to the ICD-10-CM code setEffective October 1, 2018.
FY 2020–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I72.6Overview

What is the ICD-10 code for aneurysm of vertebral artery?

The ICD-10-CM code for aneurysm of vertebral artery is I72.6 (sometimes written as I726). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I72.6 (Other aneurysm) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report aneurysm of vertebral artery on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does I72.6 group to?

When aneurysm of vertebral artery is the principal diagnosis on an inpatient stay, it groups to MS-DRG 301, 300, 299, with relative weights from 0.7132 to 1.5840 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I72.6?

Under the General Equivalence Mappings, aneurysm of vertebral artery converts to ICD-9-CM 442.81 (aneurysm of neck). The mapping is approximate, so confirm the match fits the documentation.

Does I72.6 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. I72.6 mapped to HCC 108 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 108 (Vascular Disease), ESRD (V21) category 108 (Vascular Disease), and ESRD (V24) category 108 (Vascular Disease).