What is ICD-10 code I70.233?

I70.233 is the ICD-10-CM diagnosis code for Atherosclerosis of native arteries of right leg with ulceration of ankle. Hardening and narrowing of arteries in the right leg that has caused an open sore or ulcer on the ankle. I70.233 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. I70.233 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. I70.233 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. I70.233 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 I70.233 map to under V28?

I70.233 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 I70.233 pay in RAF?

I70.233 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 I70.233?

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 I70.233, 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.

What documentation supports I70.233?

Verify documentation specifies right leg and ankle location before assigning this code Ensure the ulceration is documented as related to the atherosclerotic disease, not from another cause Because I70.233 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. See the MEAT criteria checklist at /meat-criteria for what Monitor, Evaluate, Assess, or Treat looks like in a note. MEAT is generic documentation evidence, not a payer-specific rule.

2026 ICD-10-CM I70.233: Atherosclerosis

I70.233 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 lookupI70.233Effective 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)

I70.233

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

Atherosclerosis of native arteries of right leg with ulceration of ankle

Hardening and narrowing of arteries in the right leg that has caused an open sore or ulcer on the ankle.

Buddy Insight

Atherosclerosis of native arteries with ulceration indicates severe peripheral arterial disease (Fontaine Stage IV/Rutherford Category 5) where impaired blood flow has caused tissue breakdown.

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

I70.2Atherosclerosis of native arteries of the extremities

I70.23Atherosclerosis of native arteries of right leg with ulceration

I70.233Atherosclerosis of native arteries of right leg with ulceration of ankle

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for I70.233 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for I70.233 in this effective period.

Related Child Codes

Official

I70.231Atherosclerosis of native arteries of right leg with ulceration of thigh

I70.232Atherosclerosis of native arteries of right leg with ulceration of calf

I70.234Atherosclerosis of native arteries of right leg with ulceration of heel and midfoot

I70.235Atherosclerosis of native arteries of right leg with ulceration of other part of foot

I70.238Atherosclerosis of native arteries of right leg with ulceration of other part of lower leg

Includes

Official

any condition classifiable to I70.211 and I70.221
chronic limb-threatening ischemia of native arteries of right leg with ulceration
critical limb ischemia of native arteries of right leg with ulceration

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for I70.233 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for I70.233 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 I70.233 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Clinical diagnosis of peripheral atherosclerosis explicitly documented by the provider

Specification of the affected vessel type (native arteries)

Laterality clearly documented (right leg)

Documentation of the ulcer location (ankle) with description of size, depth, and wound characteristics

MEAT Support

HCC Buddy guidance

Clinical diagnosis of peripheral atherosclerosis explicitly documented by the provider

Specification of the affected vessel type (native arteries)

Laterality clearly documented (right leg)

Documentation of the ulcer location (ankle) with description of size, depth, and wound characteristics

Audit Caution

HCC Buddy guidance

Coding bypass graft atherosclerosis codes (I70.3xx-I70.7xx) when the disease is in native arteries — verify whether the patient has a history of bypass graft surgery before selecting the code category

Failing to document the specific ulcer site (ankle) — the code requires specificity of the anatomic location of the ulcer

Coding a venous stasis ulcer or diabetic neuropathic ulcer as an atherosclerotic arterial ulcer — the etiology must be confirmed as arterial insufficiency from atherosclerosis

Not assigning an additional code from L97 or L98 to identify the ulcer severity (depth and tissue involvement) when applicable

Common Mistakes

HCC Buddy guidance

I70.3xx (bypass graft series) — Use I70.3xx when atherosclerosis involves a bypass graft rather than native arteries; the graft type must be specified when known

I70.221-I70.229 (native arteries with rest pain) — Use rest pain codes only when there is no ulceration or gangrene present; ulceration codes include the rest pain component

L97.x (Non-pressure chronic ulcer of lower limb) — L97 codes describe ulcers not specified as due to atherosclerosis; use I70.23x-I70.25 when the ulcer is clearly arterial in etiology. An additional L97 code may be assigned for ulcer severity

I70.261-I70.269 (native arteries with gangrene) — If gangrene is present along with ulceration, code the gangrene category as it represents greater severity

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 I70.233 an HCC code?

Yes. I70.233 (Atherosclerosis of native arteries of right leg with ulceration of ankle) 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: I70.233 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: I70.233
Description: Atherosclerosis of native arteries of right leg with ulceration of ankle
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 I70.233 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for I70.233

For I70.233 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 I70.233 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

I70.233 is the ICD-10-CM diagnosis code for atherosclerosis of native arteries of right leg with ulceration of ankle. Hardening and narrowing of arteries in the right leg that has caused an open sore or ulcer on the ankle. I70.233 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, I70.233 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, I70.233 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.

Verify documentation specifies right leg and ankle location before assigning this code. Because I70.233 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 I70.233 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify documentation specifies right leg and ankle location before assigning this code
•Ensure the ulceration is documented as related to the atherosclerotic disease, not from another cause

Clinical Significance

Atherosclerosis of native arteries with ulceration indicates severe peripheral arterial disease (Fontaine Stage IV/Rutherford Category 5) where impaired blood flow has caused tissue breakdown. These arterial ulcers require specialized wound care, vascular assessment, and often revascularization to promote healing and prevent amputation. This combination code captures both the underlying vascular disease and the ulcerative complication, reflecting the increased care complexity and resource needs.

Documentation Requirements

✓Clinical diagnosis of peripheral atherosclerosis explicitly documented by the provider
✓Specification of the affected vessel type (native arteries)
✓Laterality clearly documented (right leg)
✓Documentation of the ulcer location (ankle) with description of size, depth, and wound characteristics
✓Confirmation that the ulcer is arterial in etiology (as opposed to venous, diabetic neuropathic, or pressure ulcer)
✓Wound assessment details including wound bed description, drainage, presence of infection, and staging if applicable
✓Vascular assessment findings (ankle-brachial index, pulse examination, or arterial Doppler studies) supporting ischemic etiology
✓Current wound care and vascular treatment plan

Commonly Confused Codes

•I70.3xx (bypass graft series): Use I70.3xx when atherosclerosis involves a bypass graft rather than native arteries; the graft type must be specified when known
•I70.221-I70.229 (native arteries with rest pain): Use rest pain codes only when there is no ulceration or gangrene present; ulceration codes include the rest pain component
•L97.x (Non-pressure chronic ulcer of lower limb): L97 codes describe ulcers not specified as due to atherosclerosis; use I70.23x-I70.25 when the ulcer is clearly arterial in etiology. An additional L97 code may be assigned for ulcer severity
•I70.261-I70.269 (native arteries with gangrene): If gangrene is present along with ulceration, code the gangrene category as it represents greater severity
•E11.621 (Type 2 diabetes mellitus with foot ulcer): Diabetic foot ulcers are coded differently; if both atherosclerosis and diabetes contribute, both conditions should be coded