What is ICD-10 code I70.731?

I70.731 is the ICD-10-CM diagnosis code for Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of thigh. Hardening and narrowing of a bypass graft in the right leg with an open sore on the thigh. I70.731 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. I70.731 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. I70.731 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. I70.731 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 I70.731?

I70.731 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards I70.731 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting I70.731?

Confirm the ulceration is specifically on the thigh and not another part of the right leg Document the stage and severity of the ulcer for complete clinical picture

I70.731 ICD-10 Code: Atherosclerosis of other type

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 lookupI70.731Effective 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)

I70.731

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

Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of thigh

Hardening and narrowing of a bypass graft in the right leg with an open sore on the thigh.

Buddy Insight

Atherosclerosis of other type bypass graft of the right leg with ulceration of the thigh represents advanced peripheral arterial disease with tissue breakdown (Fontaine Stage IV).

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 311

Diabetic and Chronic Skin Ulcer

RAF 0.0

Code Trumping

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Compare selected patient codes to show trumped or trumps impact.

Code Book Path

Official

I70.7Atherosclerosis of other type of bypass graft(s) of the extremities

I70.73Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration

I70.731Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of thigh

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for I70.731 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for I70.731 in this effective period.

Related Child Codes

Official

I70.732Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of calf

I70.733Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of ankle

I70.734Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of heel and midfoot

I70.735Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of other part of foot

I70.738Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of other part of lower leg

Includes

Official

any condition classifiable to I70.711 and I70.721
chronic limb-threatening ischemia of other type of bypass graft(s) of the right leg with ulceration
critical limb ischemia of other type of bypass graft(s) of the right leg with ulceration

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for I70.731 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for I70.731 in this effective period.

Use Additional

Official

code to identify severity of ulcer (L97.-)

Code Also

Official

ICD-10-CM does not list Code Also instructions for I70.731 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documented atherosclerotic disease specifically of other type bypass graft(s) in the right leg

Active ulceration at the thigh clearly described — including size, depth, and wound characteristics

Laterality confirmed as right leg

Type of bypass graft specified (synthetic, composite, or other non-vein/non-biological type)

MEAT Support

HCC Buddy guidance

Documented atherosclerotic disease specifically of other type bypass graft(s) in the right leg

Active ulceration at the thigh clearly described — including size, depth, and wound characteristics

Laterality confirmed as right leg

Type of bypass graft specified (synthetic, composite, or other non-vein/non-biological type)

Audit Caution

HCC Buddy guidance

Forgetting to assign an additional code from L97.- to specify the severity/layer of the ulcer — this combination code requires a secondary ulcer severity code

Selecting the wrong graft type category — verify the chart specifies synthetic/other type graft, not autologous vein or nonautologous biological

Coding the wrong ulcer site within the right leg — verify exact anatomical location (thigh vs. calf vs. ankle vs. heel/midfoot vs. other foot)

Missing laterality — these codes are specific to the right leg; do not use if documentation says left leg or bilateral

Common Mistakes

HCC Buddy guidance

I70.531/I70.532/I70.535 — Atherosclerosis of nonautologous biological bypass graft of the right leg with ulceration (different graft type)

I70.431/I70.432/I70.435 — Atherosclerosis of autologous vein bypass graft of the right leg with ulceration (different graft type — autologous vein)

I70.231/I70.232/I70.235 — Atherosclerosis of native arteries of right leg with ulceration (native artery, not bypass graft)

I70.741-I70.749 — Same condition but left leg instead of right leg

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is I70.731 an HCC code?

No. I70.731 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

RxHCCHCC 311, Diabetic and Chronic Skin Ulcer

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.

MEAT Criteria for I70.731

For I70.731to 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 I70.731 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

I70.731 is the ICD-10-CM diagnosis code for atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of thigh. Hardening and narrowing of a bypass graft in the right leg with an open sore on the thigh. I70.731 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).

I70.731 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Does not map to a CMS-HCC in the V28 model. Does not map to a CMS-HCC in the V24 model. In the RxHCC model, maps to RxHCC 311 (Diabetic Foot Ulcer) with RAF weight 0.0. Although this code does not map to a CMS-HCC in V28 or V24, it maps to the RxHCC model and remains clinically significant. When gangrene is also present, code the gangrene manifestation (I70.761) instead, which maps to higher-weighted HCCs.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for I70.731 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Confirm the ulceration is specifically on the thigh and not another part of the right leg
•Document the stage and severity of the ulcer for complete clinical picture

Clinical Significance

Atherosclerosis of other type bypass graft of the right leg with ulceration of the thigh represents advanced peripheral arterial disease with tissue breakdown (Fontaine Stage IV). The presence of ulceration indicates critical limb ischemia with active tissue loss, significantly increasing the risk of infection, gangrene, and potential amputation. This condition demands intensive wound care, vascular surveillance, and often revascularization procedures, making accurate documentation critical for appropriate resource allocation.

Documentation Requirements

✓Documented atherosclerotic disease specifically of other type bypass graft(s) in the right leg
✓Active ulceration at the thigh clearly described — including size, depth, and wound characteristics
✓Laterality confirmed as right leg
✓Type of bypass graft specified (synthetic, composite, or other non-vein/non-biological type)
✓Severity/classification of ulcer (e.g., Wagner grade, University of Texas classification) when available
✓Additional code from L97.- or L98.49- to specify ulcer severity (non-pressure chronic ulcer codes)
✓Current wound care plan and any vascular intervention being considered
✓Assessment of perfusion status (ABI, toe pressures, or other vascular studies)

Commonly Confused Codes

•I70.531/I70.532/I70.535: Atherosclerosis of nonautologous biological bypass graft of the right leg with ulceration (different graft type)
•I70.431/I70.432/I70.435: Atherosclerosis of autologous vein bypass graft of the right leg with ulceration (different graft type: autologous vein)
•I70.231/I70.232/I70.235: Atherosclerosis of native arteries of right leg with ulceration (native artery, not bypass graft)
•I70.741-I70.749: Same condition but left leg instead of right leg
•L97.111-L97.929: Non-pressure chronic ulcer codes that should be used as additional codes to specify ulcer severity