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.

Which HCC does I70.731 map to under V28?

I70.731 maps to CMS-HCC V28 263 (Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene). The category number and label come from the CMS-HCC V28 model file for payment year 2026.

What does I70.731 pay in RAF?

I70.731 carries a community, non-dual, aged (CNA) RAF weight of 1.118 under CMS-HCC V28 for payment year 2026. The weight comes from the CMS V28 relative-factor file, not a hand-typed table.

What is the V28 vs V24 difference for I70.731?

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 I70.731, V28 maps to Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene at RAF 1.118 while V24 mapped to Atherosclerosis of the Extremities with Ulceration or Gangrene at RAF 1.488. Both models can still appear in legacy data and in payer-specific lookback periods.

2026 ICD-10-CM I70.731: Atherosclerosis of other

I70.731 maps to CMS-HCC V28 263 (RAF 1.118). Documentation must support MEAT. MEAT criteria · RAF calculator · free HCC coding tools

ICD-10-CM Code View

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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

Mapped

HCC 263

Atherosclerosis of Arteries o...

RAF 1.118

CMS-HCC V24

Mapped

HCC 106

Atherosclerosis of the Extrem...

RAF 1.488

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

Mapped

HCC 106

Atherosclerosis of the Extrem...

RAF 0.358

RXHCC

Mapped

HCC 311

Diabetic and Chronic Skin Ulcer

RAF 0.175

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

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 I70.731 an HCC code?

Yes. I70.731 (Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of thigh) maps to Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene under the CMS-HCC V28 risk adjustment model (and Atherosclerosis of the Extremities with Ulceration or Gangrene under V24), with a community non-dual aged RAF of 1.118. It is billable for payment year 2026.

Coder answer: I70.731 is billable and maps to V28 HCC 263, Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: I70.731
Description: Atherosclerosis of other type of bypass graft(s) of the right leg with ulceration of thigh
HCC (V28): HCC 263 — Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene
RAF: 1.118
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 263, Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene

1.118

V24HCC 106, Atherosclerosis of the Extremities with Ulceration or Gangrene

1.488

ESRDHCC 106, Atherosclerosis of the Extremities with Ulceration or Gangrene

0.358

RxHCCHCC 311, Diabetic and Chronic Skin Ulcer

0.175

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 I70.731 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for I70.731

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

Coder workflow notes

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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).

Under the CMS-HCC V28 risk adjustment model, I70.731 maps to Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene (HCC 263) with a community, non-dual, aged base RAF weight of 1.118. Under the older CMS-HCC V24 model, I70.731 maps to Atherosclerosis of the Extremities with Ulceration or Gangrene (HCC 106) with a community, non-dual, aged base RAF weight of 1.488. 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.

Confirm the ulceration is specifically on the thigh and not another part of the right leg. Because I70.731 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 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