I71.9 ICD-10-CM Code: Aortic aneurysm of unspecified site, without rupture
I71.9 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC coding software
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FY 2026 Apr update / Diseases of the circulatory system (I00-I99) / Diseases of arteries, arterioles and capillaries (I70-I79)
I71.9
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAortic aneurysm of unspecified site, without rupture
A bulging or weakening of the aorta at a location that is not specifically identified or classified elsewhere, and it has not ruptured.
Buddy Insight
Aortic aneurysm of unspecified site without rupture indicates the presence of aortic aneurysmal disease but lacks anatomic specificity.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
N/A—
Not mapped
ESRD/PACE
MappedHCC 108
Code-level coefficient reference
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Aneurysm of aorta
- Dilatation of aorta
- Hyaline necrosis of aorta
Excludes 2
Official- certain conditions originating in the perinatal period (P04-P96)Inherited from I00-I99
- certain infectious and parasitic diseases (A00-B99)Inherited from I00-I99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from I00-I99
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from I00-I99
- endocrine, nutritional and metabolic diseases (E00-E88)Inherited from I00-I99
- injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from I00-I99
- neoplasms (C00-D49)Inherited from I00-I99
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from I00-I99
- systemic connective tissue disorders (M30-M36)Inherited from I00-I99
- transient cerebral ischemic attacks and related syndromes (G45.-)Inherited from I00-I99
Related Codes
Includes
OfficialNo Includes notes are included in this display for I71.9. Check the code and parent instructions in the Code Book.
Excludes 1
OfficialNo Excludes 1 notes are included in this display for I71.9. Check the code and parent instructions in the Code Book.
Code First
Official- , if applicable:Inherited from I71
- syphilitic aortic aneurysm (A52.01)Inherited from I71
- traumatic aortic aneurysm (S25.09, S35.09)Inherited from I71
Use Additional
OfficialNo Use Additional Code instructions are included in this display for I71.9. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for I71.9. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 I71.9 an HCC code?
I71.9 has no mapping under the current CMS-HCC V28 community payment model. I71.9 has a separate mapping under the CMS-HCC ESRD model (HCC 108 (Vascular Disease)); the applicable result needs member context.
- Code
- I71.9
- Description
- Aortic aneurysm of unspecified site, without rupture
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF reference coefficient
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
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 I71.9 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for I71.9
For I71.9, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- 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
Coder workflow notes
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What This Code Means
I71.9 is the ICD-10-CM diagnosis code for aortic aneurysm of unspecified site, without rupture. A bulging or weakening of the aorta at a location that is not specifically identified or classified elsewhere, and it has not ruptured. I71.9 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).
I71.9 has no mapping under the current CMS-HCC V28 community payment model. I71.9 has a separate mapping under the CMS-HCC ESRD model (HCC 108 (Vascular Disease)); the applicable result needs member context. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.
This unspecified code should be used only when the exact aortic location cannot be determined from available documentation.
HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for I71.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This unspecified code should be used only when the exact aortic location cannot be determined from available documentation
- •Attempt to obtain more specific imaging or clinical documentation to assign a more precise code
Clinical Significance
Aortic aneurysm of unspecified site without rupture indicates the presence of aortic aneurysmal disease but lacks anatomic specificity. While this captures the diagnosis for risk adjustment, it represents a missed opportunity for precise coding. The condition requires ongoing surveillance and carries risk of progression to rupture, making it important for resource planning.
Documentation Requirements
- ✓Documentation of aortic aneurysm diagnosis
- ✓Imaging confirmation with measurements when available
- ✓Statement confirming no rupture or leak
- ✓Attempt to determine specific location from imaging reports
- ✓Surveillance plan and follow-up imaging schedule
- ✓Risk factor management (blood pressure control, smoking cessation)
Commonly Confused Codes
- •I71.2: Thoracic aortic aneurysm, without rupture: use when thoracic location is specified
- •I71.4: Abdominal aortic aneurysm, without rupture: use when abdominal location is specified
- •I71.60: Thoracoabdominal aortic aneurysm, without rupture: use when both segments involved
- •I71.8: Aortic aneurysm of unspecified site, ruptured: ruptured version carries higher HCC weight