What is ICD-10 code I71.011?

I71.011 is the ICD-10-CM diagnosis code for Dissection of aortic arch. A tear in the wall of the aortic arch (the curved portion of the main artery) where the inner and outer layers separate. It belongs to the ICD-10-CM chapter for diseases of the circulatory system (i00-i99). I71.011 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. I71.011 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. I71.011 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. I71.011 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.

Which HCC does I71.011 map to under V28?

I71.011 maps to CMS-HCC V28 HCC 264 (Vascular Disease with Complications). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM I71.011: Dissection of aortic arch

I71.011 maps to CMS-HCC V28 264. A source-labeled RAF reference is available. Documentation must support MEAT. MEAT criteria · RAF Calculator · HCC Buddy coding tools

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupI71.011Effective 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)

I71.011

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

Dissection of aortic arch

A tear in the wall of the aortic arch (the curved portion of the main artery) where the inner and outer layers separate.

Buddy Insight

CMS-HCC V28

Mapped

HCC 264

Vascular Disease with Complic...

Code-level coefficient reference

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 154

HHS-HCC 154 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 107

Vascular Disease with Complic...

Code-level coefficient reference

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

I71.0Dissection of aorta

I71.01Dissection of thoracic aorta

I71.011Dissection of aortic arch

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for I71.011 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for I71.011 in this effective period.

Related Child Codes

Official

I71.010Dissection of ascending aorta

I71.012Dissection of descending thoracic aorta

I71.019Dissection of thoracic aorta, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for I71.011 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for I71.011 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for I71.011 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for I71.011 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for I71.011 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Aortic dissection explicitly documented at the aortic arch

Classification type documented when possible (Stanford Type A or B, DeBakey I, II, or III)

Imaging confirmation (CT angiography, MRI, transesophageal echocardiography, or surgical findings)

Acute vs. chronic status clarified — this code may be used for both, but clinical context should be clear

MEAT Support

HCC Buddy guidance

Aortic dissection explicitly documented at the aortic arch

Classification type documented when possible (Stanford Type A or B, DeBakey I, II, or III)

Imaging confirmation (CT angiography, MRI, transesophageal echocardiography, or surgical findings)

Acute vs. chronic status clarified — this code may be used for both, but clinical context should be clear

Audit Caution

HCC Buddy guidance

Confusing aortic dissection with aortic aneurysm — dissection involves intimal tear with false lumen formation, while aneurysm is dilation of the vessel; they can coexist but are distinct diagnoses

Failing to specify the anatomical site of dissection when documented — ascending, arch, descending thoracic, abdominal, and thoracoabdominal each have distinct codes

Not distinguishing between acute and chronic (healed) dissection in the documentation — both map the same but clinical management differs significantly

Missing associated complications that warrant additional codes (aortic regurgitation, malperfusion, hemopericardium)

Common Mistakes

HCC Buddy guidance

I71.10-I71.13 — Thoracic aortic aneurysm, ruptured (aneurysm rupture is different from dissection — though they can coexist)

I71.20-I71.23 — Thoracic aortic aneurysm, without rupture (aneurysm without dissection)

I71.30-I71.33 — Abdominal aortic aneurysm, ruptured (different condition — rupture vs. dissection)

I77.810-I77.812 — Aortic ectasia (dilation without aneurysm or dissection)

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 I71.011 an HCC code?

Yes. I71.011 (Dissection of aortic arch) maps to HCC 264, Vascular Disease with Complications under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.455. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: I71.011 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: I71.011
Description: Dissection of aortic arch
HCC (V28): HCC 264 — Vascular Disease with Complications
RAF reference coefficient: 0.455
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 264, Vascular Disease with Complications

0.455

ESRDHCC 107, Vascular Disease with Complications

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. 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 context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work I71.011 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT Criteria for I71.011

For I71.011 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 I71.011 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

I71.011 is the ICD-10-CM diagnosis code for dissection of aortic arch. A tear in the wall of the aortic arch (the curved portion of the main artery) where the inner and outer layers separate. I71.011 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, I71.011 maps to Vascular Disease with Complications (HCC 264) with a source-labeled community, non-dual, aged reference coefficient of 0.455. No V24 mapping is shown for I71.011; use the applicable model and payment year when reviewing the V28 mapping. 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. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

The aortic arch is a specific anatomical location; ensure documentation clearly identifies this region. Because I71.011 maps to an HCC category, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment. 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, source-labeled coefficient references, and MEAT documentation criteria for I71.011 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•The aortic arch is a specific anatomical location; ensure documentation clearly identifies this region
•Consider whether the dissection extends beyond the arch, which may require additional codes

Clinical Significance

Dissection of the aortic arch is a life-threatening emergency where a tear in the aortic intima allows blood to enter the vessel wall, creating a false lumen that can propagate and compromise branch vessel perfusion. Aortic dissection carries high mortality without prompt diagnosis and treatment, and survivors require lifelong surveillance for aneurysm development, re-dissection, and end-organ damage. This is a high-acuity diagnosis that significantly impacts risk adjustment, reflecting the intensive acute care and ongoing management these patients require.

Documentation Requirements

✓Aortic dissection explicitly documented at the aortic arch
✓Classification type documented when possible (Stanford Type A or B, DeBakey I, II, or III)
✓Imaging confirmation (CT angiography, MRI, transesophageal echocardiography, or surgical findings)
✓Acute vs. chronic status clarified — this code may be used for both, but clinical context should be clear
✓Extent of dissection (which segments of aorta are involved)
✓Complications documented (malperfusion syndrome, aortic regurgitation, pericardial effusion, end-organ ischemia)
✓Current management plan (medical, endovascular, or open surgical repair)

Commonly Confused Codes

•I71.10-I71.13: Thoracic aortic aneurysm, ruptured (aneurysm rupture is different from dissection: though they can coexist)
•I71.20-I71.23: Thoracic aortic aneurysm, without rupture (aneurysm without dissection)
•I71.30-I71.33: Abdominal aortic aneurysm, ruptured (different condition: rupture vs. dissection)
•I77.810-I77.812: Aortic ectasia (dilation without aneurysm or dissection)