I70.742 maps to CMS-HCC V28 HCCs 263 and 383. Source-labeled RAF references are available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC coding software

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Code lookupI70.742

Effective 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)

I70.742

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

Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of calf

Hardening of arteries in a bypass graft in the left leg with an open sore on the calf.

Buddy Insight

Atherosclerosis of other type bypass graft of the left leg with ulceration of the calf represents advanced peripheral arterial disease with active tissue loss (Fontaine Stage IV).

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 263

Atherosclerosis of Arteries o...

Coefficient HCC 263: 1.118 (Community Non-Dual Aged (CNA)); HCC 383: 0.646 (Community Non-Dual Aged (CNA))

+ HCC 383

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

Context needed

HCC 153, HCC 217

Conditional HHS-HCC mapping: HCC 153 when age >=15; HCC 217 when age >=15. Select the member context before showing a coefficient reference. Metal level and model segment are required for coefficients; no single RAF is shown.

Coefficient needs member context

ESRD/PACE

Context needed

HCC 106, HCC 161

ESRD candidates: HCC 106 when age >= 15; HCC 161 when age >= 15. ESRD mapping is separate from PACE. Dialysis, graft, age, and other member context determine the applicable coefficient.

Coefficient needs member context

RXHCC

Context needed

HCC 311

RxHCC candidates: HCC 311 when age >= 15. RxHCC mapping is current. Member segment is still required before using a coefficient.

Coefficient needs member context

Code Book Path

Official

I70.7Atherosclerosis of other type of bypass graft(s) of the extremities I70.74Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration I70.742Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of calf

Inclusion Terms

Official

No inclusion terms are included in this display for I70.742. Check the code and parent instructions in the Code Book.

Excludes 2

Official

certain conditions originating in the perinatal period (P04-P96)Inherited from I00-I99, I70
certain infectious and parasitic diseases (A00-B99)Inherited from I00-I99, I70
complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from I00-I99, I70
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from I00-I99, I70
endocrine, nutritional and metabolic diseases (E00-E88)Inherited from I00-I99, I70
injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from I00-I99, I70
neoplasms (C00-D49)Inherited from I00-I99, I70
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from I00-I99, I70
systemic connective tissue disorders (M30-M36)Inherited from I00-I99, I70
transient cerebral ischemic attacks and related syndromes (G45.-)Inherited from I00-I99, I70
arteriosclerotic cardiovascular disease (I25.1-)Inherited from I00-I99, I70
arteriosclerotic heart disease (I25.1-)Inherited from I00-I99, I70
atheroembolism (I75.-)Inherited from I00-I99, I70
cerebral atherosclerosis (I67.2)Inherited from I00-I99, I70
coronary atherosclerosis (I25.1-)Inherited from I00-I99, I70
mesenteric atherosclerosis (K55.1)Inherited from I00-I99, I70
precerebral atherosclerosis (I67.2)Inherited from I00-I99, I70
primary pulmonary atherosclerosis (I27.0)Inherited from I00-I99, I70

Related Codes

Official

I70.741Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of thigh I70.743Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of ankle I70.744Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of heel and midfoot I70.745Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of other part of foot I70.748Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of other part of lower leg

Includes

Official

arteriolosclerosisInherited from I70, I70.74
arterial degenerationInherited from I70, I70.74
arteriosclerosisInherited from I70, I70.74
arteriosclerotic vascular diseaseInherited from I70, I70.74
arteriovascular degenerationInherited from I70, I70.74
atheromaInherited from I70, I70.74
endarteritis deformans or obliteransInherited from I70, I70.74
senile arteritisInherited from I70, I70.74
senile endarteritisInherited from I70, I70.74
vascular degenerationInherited from I70, I70.74
any condition classifiable to I70.712 and I70.722Inherited from I70, I70.74
chronic limb-threatening ischemia of other type of bypass graft(s) of the left leg with ulcerationInherited from I70, I70.74
critical limb ischemia of other type of bypass graft(s) of the left leg with ulcerationInherited from I70, I70.74

Excludes 1

Official

No Excludes 1 notes are included in this display for I70.742. Check the code and parent instructions in the Code Book.

Code First

Official

No Code First sequencing instructions are included in this display for I70.742. Check the code and parent instructions in the Code Book.

Use Additional

Official

code to identify:Inherited from I70, I70.7, I70.74
exposure to environmental tobacco smoke (Z77.22)Inherited from I70, I70.7, I70.74
history of tobacco dependence (Z87.891)Inherited from I70, I70.7, I70.74
occupational exposure to environmental tobacco smoke (Z57.31)Inherited from I70, I70.7, I70.74
tobacco dependence (F17.-)Inherited from I70, I70.7, I70.74
tobacco use (Z72.0)Inherited from I70, I70.7, I70.74
code, if applicable, to identify chronic total occlusion of artery of extremity (I70.92)Inherited from I70, I70.7, I70.74
code to identify severity of ulcer (L97.-)Inherited from I70, I70.7, I70.74

Code Also

Official

No Code Also instructions are included in this display for I70.742. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

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

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

Laterality confirmed as left 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 left leg

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

Laterality confirmed as left leg

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

Audit Caution

HCC Buddy guidance

Failing to assign an additional L97.- code to indicate ulcer severity — these combination codes require a secondary code for the ulcer layer involvement

Selecting wrong graft type — must be 'other type' (synthetic/composite), not autologous vein or nonautologous biological bypass

Miscoding the anatomical site of ulceration — verify documentation specifies calf on the left leg

Confusing left and right laterality — these codes are specific to the left leg

Common Mistakes

HCC Buddy guidance

I70.541/I70.542/I70.545 — Atherosclerosis of nonautologous biological bypass graft of the left leg with ulceration (different graft type)

I70.441/I70.442/I70.445 — Atherosclerosis of autologous vein bypass graft of the left leg with ulceration (different graft type)

I70.241/I70.242/I70.245 — Atherosclerosis of native arteries of left leg with ulceration (native artery, not a bypass graft)

I70.731-I70.739 — Same condition but right leg instead of left 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 I70.742 an HCC code?

Yes. I70.742 (Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of calf) maps to HCC 263, Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene and HCC 383, Chronic Ulcer of Skin, Except Pressure, Not Specified as Through to Bone or Muscle under the CMS-HCC V28 risk adjustment model, with source-labeled community non-dual aged reference coefficients HCC 263 1.118 and HCC 383 0.646. 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: I70.742 is billable and maps to V28 HCC 263, Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene and HCC 383, Chronic Ulcer of Skin, Except Pressure, Not Specified as Through to Bone or Muscle. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: I70.742
Description: Atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of calf
HCC (V28): HCC 263 — Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene; HCC 383 — Chronic Ulcer of Skin, Except Pressure, Not Specified as Through to Bone or Muscle
RAF reference coefficient: HCC 263: 1.118; HCC 383: 0.646
Billable: Yes
Payment year: 2026

HCC Category Mapping

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

1.118

+ HCC 383, Chronic Ulcer of Skin, Except Pressure, Not Specified as Through to Bone or Muscle0.646

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 I70.742 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for I70.742

For I70.742, 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

I70.742 is the ICD-10-CM diagnosis code for atherosclerosis of other type of bypass graft(s) of the left leg with ulceration of calf. Hardening of arteries in a bypass graft in the left leg with an open sore on the calf. I70.742 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, I70.742 maps to Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene (HCC 263) with a source-labeled community, non-dual, aged reference coefficient of 1.118. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. 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.

Confirm the ulceration is on the calf (lower leg between knee and ankle) rather than other leg locations. For I70.742, 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. 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 I70.742 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Confirm the ulceration is on the calf (lower leg between knee and ankle) rather than other leg locations.
•Document the depth and severity of the ulcer, as this may require additional codes for wound care complexity.

Clinical Significance

Atherosclerosis of other type bypass graft of the left leg with ulceration of the calf represents advanced peripheral arterial disease with active tissue loss (Fontaine Stage IV). Ulceration from arterial insufficiency through a bypass graft indicates graft dysfunction or progression of atherosclerotic disease, carrying substantial risk for limb loss. Accurate coding captures the complexity of managing combined graft disease with wound care needs, ensuring appropriate risk adjustment and care planning.

Documentation Requirements

✓Documented atherosclerotic disease specifically of other type bypass graft(s) in the left leg
✓Active ulceration at the calf clearly described — including size, depth, and wound characteristics
✓Laterality confirmed as left leg
✓Type of bypass graft specified (synthetic, composite, or other non-vein/non-biological type)
✓Severity/classification of ulcer documented (e.g., Wagner grade, wound staging)
✓Additional code from L97.- or L98.49- to specify ulcer severity
✓Current wound care regimen and vascular management plan documented
✓Vascular studies or perfusion assessment results when available

Commonly Confused Codes

•I70.541/I70.542/I70.545: Atherosclerosis of nonautologous biological bypass graft of the left leg with ulceration (different graft type)
•I70.441/I70.442/I70.445: Atherosclerosis of autologous vein bypass graft of the left leg with ulceration (different graft type)
•I70.241/I70.242/I70.245: Atherosclerosis of native arteries of left leg with ulceration (native artery, not a bypass graft)
•I70.731-I70.739: Same condition but right leg instead of left leg
•L97.211-L97.929: Non-pressure chronic ulcer codes used as additional codes to specify ulcer depth and severity