What is ICD-10 code I71.8?

I71.8 is the ICD-10-CM diagnosis code for Aortic aneurysm of unspecified site, ruptured. A ruptured bulging of the aorta at a location that is not specifically identified or classified elsewhere. It belongs to the ICD-10-CM chapter for diseases of the circulatory system (i00-i99). I71.8 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. I71.8 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. I71.8 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. I71.8 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for I71.8?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For I71.8, V28 maps to Vascular Disease with Complications at RAF 0.455 while V24 mapped to Vascular Disease with Complications at RAF 0.383. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting I71.8?

This is a catch-all code for ruptured aortic aneurysms that don't fit other categories; use only when site cannot be determined This is an emergent condition; ensure documentation includes rupture status and any complications Because I71.8 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

2026 ICD-10-CM I71.8: Aortic aneurysm

ICD-10-CM Code View

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Code lookupI71.8Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the circulatory system (I00-I99) / Diseases of arteries, arterioles and capillaries (I70-I79)

I71.8

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Aortic aneurysm of unspecified site, ruptured

A ruptured bulging of the aorta at a location that is not specifically identified or classified elsewhere.

Buddy Insight

Ruptured aortic aneurysm of unspecified site is a life-threatening emergency regardless of the exact location within the aorta.

CMS-HCC V28

Mapped

HCC 264

Vascular Disease with Complic...

RAF 0.455

CMS-HCC V24

Mapped

HCC 107

Vascular Disease with Complic...

RAF 0.383

ACA/HHS

Mapped

HCC 154

HHS-HCC 154

Varies by metal level

ESRD/PACE

Mapped

HCC 107

Vascular Disease with Complic...

RAF 0.144

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

I71Aortic aneurysm and dissection

I71.8Aortic aneurysm of unspecified site, ruptured

Inclusion Terms

Official

Rupture of aorta NOS

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for I71.8 in this effective period.

Related Child Codes

Official

I71.0Dissection of aorta

I71.1Thoracic aortic aneurysm, ruptured

I71.2Thoracic aortic aneurysm, without rupture

I71.3Abdominal aortic aneurysm, ruptured

I71.4Abdominal aortic aneurysm, without rupture

Includes

Official

ICD-10-CM does not list Includes notes for I71.8 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for I71.8 in this effective period.

Code First

Official

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

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for I71.8 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for I71.8 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation confirming aortic aneurysm with rupture

Evidence of rupture: imaging findings, hemodynamic instability, or surgical confirmation

Attempt to clarify specific location (thoracic, abdominal, or thoracoabdominal)

Emergency treatment and resuscitation documentation

MEAT Support

HCC Buddy guidance

Documentation confirming aortic aneurysm with rupture

Evidence of rupture: imaging findings, hemodynamic instability, or surgical confirmation

Attempt to clarify specific location (thoracic, abdominal, or thoracoabdominal)

Emergency treatment and resuscitation documentation

Audit Caution

HCC Buddy guidance

Using this unspecified code when operative or imaging reports clearly identify the anatomic location

Not querying the provider for anatomic specificity — surgical and imaging reports almost always specify the location

Coding ruptured based on a history of prior rupture when the current aneurysm is intact

Failing to review all available documentation (radiology, surgery, emergency department) for location details before defaulting to unspecified

Common Mistakes

HCC Buddy guidance

I71.1 — Thoracic aortic aneurysm, ruptured: use when thoracic location is documented

I71.3 — Abdominal aortic aneurysm, ruptured: use when abdominal location is documented

I71.50 — Thoracoabdominal aortic aneurysm, ruptured, unspecified: use when both segments involved

I71.9 — Aortic aneurysm of unspecified site, without rupture: intact version without rupture

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is I71.8 an HCC code?

Yes. I71.8 (Aortic aneurysm of unspecified site, ruptured) maps to Vascular Disease with Complications under the CMS-HCC V28 risk adjustment model (and Vascular Disease with Complications under V24), with a community non-dual aged RAF of 0.455. It is billable for payment year 2026.

Coder answer: I71.8 is billable and maps to V28 HCC 264, Vascular Disease with Complications. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: I71.8
Description: Aortic aneurysm of unspecified site, ruptured
HCC (V28): HCC 264 — Vascular Disease with Complications
RAF: 0.455
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 264, Vascular Disease with Complications

0.455

V24HCC 107, Vascular Disease with Complications

0.383

ESRDHCC 107, Vascular Disease with Complications

0.144

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work I71.8 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for I71.8

For I71.8 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed I71.8 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

I71.8 is the ICD-10-CM diagnosis code for aortic aneurysm of unspecified site, ruptured. A ruptured bulging of the aorta at a location that is not specifically identified or classified elsewhere. I71.8 sits in the ICD-10-CM chapter for diseases of the circulatory system (i00-i99), within the section covering diseases of arteries, arterioles and capillaries (i70-i79).

Under the CMS-HCC V28 risk adjustment model, I71.8 maps to Vascular Disease with Complications (HCC 264) with a community, non-dual, aged base RAF weight of 0.455. Under the older V24 model, I71.8 mapped to the same category but with a base RAF weight of 0.383, V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

This is a catch-all code for ruptured aortic aneurysms that don't fit other categories; use only when site cannot be determined. Because I71.8 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for I71.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This is a catch-all code for ruptured aortic aneurysms that don't fit other categories; use only when site cannot be determined
•This is an emergent condition; ensure documentation includes rupture status and any complications

Clinical Significance

Ruptured aortic aneurysm of unspecified site is a life-threatening emergency regardless of the exact location within the aorta. While this code should be used only when the specific location cannot be determined, it still reflects a critically ill patient requiring emergent intervention. The unspecified nature often reflects incomplete documentation that should be clarified when possible.

Documentation Requirements

✓Documentation confirming aortic aneurysm with rupture
✓Evidence of rupture: imaging findings, hemodynamic instability, or surgical confirmation
✓Attempt to clarify specific location (thoracic, abdominal, or thoracoabdominal)
✓Emergency treatment and resuscitation documentation
✓Hemodynamic parameters and blood product utilization
✓If location is subsequently determined, update coding to specific site

Commonly Confused Codes

•I71.1: Thoracic aortic aneurysm, ruptured: use when thoracic location is documented
•I71.3: Abdominal aortic aneurysm, ruptured: use when abdominal location is documented
•I71.50: Thoracoabdominal aortic aneurysm, ruptured, unspecified: use when both segments involved
•I71.9: Aortic aneurysm of unspecified site, without rupture: intact version without rupture