What is ICD-10 code I70.322?

I70.322 is the ICD-10-CM diagnosis code for Atherosclerosis of unspecified type of bypass graft(s) of the extremities with rest pain, left leg. Hardening and narrowing of a bypass graft in the left leg causing pain even at rest, indicating severe circulation problems. I70.322 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. I70.322 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. I70.322 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. I70.322 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 I70.322?

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 I70.322, V28 maps to Vascular Disease with Complications at RAF 0.356 while V24 mapped to Vascular Disease at RAF 0.297. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting I70.322?

Verify documentation specifies left leg location and rest pain component Confirm bypass graft type is truly unspecified; if type is documented (venous, arterial, nonautologous), use more specific code Because I70.322 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.

I70.322 ICD-10 Code: Atherosclerosis

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 lookupI70.322Effective 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)

I70.322

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

Atherosclerosis of unspecified type of bypass graft(s) of the extremities with rest pain, left leg

Hardening and narrowing of a bypass graft in the left leg causing pain even at rest, indicating severe circulation problems.

Buddy Insight

Atherosclerosis of bypass graft(s) with rest pain indicates critical limb ischemia (Fontaine Stage III/Rutherford Category 4), where blood flow is insufficient even at rest.

CMS-HCC V28

Mapped

HCC 264

Vascular Disease with Complic...

RAF 0.356

CMS-HCC V24

Mapped

HCC 108

Vascular Disease

RAF 0.297

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 108

Vascular Disease

RAF 0.0

RXHCC

Not risk-adjusted for this model/period.

RAF 0

Code Trumping

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Compare selected patient codes to show trumped or trumps impact.

Code Book Path

Official

I70.3Atherosclerosis of unspecified type of bypass graft(s) of the extremities

I70.32Atherosclerosis of unspecified type of bypass graft(s) of the extremities with rest pain

I70.322Atherosclerosis of unspecified type of bypass graft(s) of the extremities with rest pain, left leg

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for I70.322 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for I70.322 in this effective period.

Related Child Codes

Official

I70.321Atherosclerosis of unspecified type of bypass graft(s) of the extremities with rest pain, right leg

I70.323Atherosclerosis of unspecified type of bypass graft(s) of the extremities with rest pain, bilateral legs

I70.328Atherosclerosis of unspecified type of bypass graft(s) of the extremities with rest pain, other extremity

I70.329Atherosclerosis of unspecified type of bypass graft(s) of the extremities with rest pain, unspecified extremity

Includes

Official

any condition classifiable to I70.31-
chronic limb-threatening ischemia NOS of unspecified type of bypass graft(s) of the extremities
chronic limb-threatening ischemia of unspecified type of bypass graft(s) of the extremities with rest pain
critical limb ischemia NOS of unspecified type of bypass graft(s) of the extremities
critical limb ischemia of unspecified type of bypass graft(s) of the extremities with rest pain

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for I70.322 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for I70.322 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for I70.322 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for I70.322 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 (bypass graft(s))

Laterality clearly documented (left leg)

Documentation of rest pain — ischemic pain occurring at rest, typically in the forefoot, worsening with elevation and improving with dependency

MEAT Support

HCC Buddy guidance

Clinical diagnosis of peripheral atherosclerosis explicitly documented by the provider

Specification of the affected vessel type (bypass graft(s))

Laterality clearly documented (left leg)

Documentation of rest pain — ischemic pain occurring at rest, typically in the forefoot, worsening with elevation and improving with dependency

Audit Caution

HCC Buddy guidance

Using native artery codes (I70.2xx) when the patient has a documented bypass graft — always verify surgical history and code to the appropriate graft category

Defaulting to unspecified graft type when the medical record documents the specific graft type (autologous vein, nonnautologous biological, or nonbiological) — query the record for graft details before coding to unspecified

Confusing rest pain with intermittent claudication — rest pain occurs at rest (typically nocturnal forefoot pain relieved by dependency), while claudication is exertional pain relieved by rest

Failing to verify laterality documentation — unspecified laterality codes should be avoided when the affected side is documented in the record

Common Mistakes

HCC Buddy guidance

I70.2xx (native artery series) — Use I70.2xx when atherosclerosis involves the native arteries rather than a bypass graft; do not use bypass graft codes without documentation of prior graft surgery

I70.311-I70.319 (bypass graft with intermittent claudication) — Claudication is exertional pain relieved by rest; rest pain indicates more severe critical limb ischemia

I70.331-I70.35 (bypass graft with ulceration) — If ulceration is present along with rest pain, code the ulceration as it represents greater tissue compromise

I70.361-I70.369 (bypass graft with gangrene) — Gangrene codes supersede rest pain codes when tissue necrosis is documented

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 I70.322 an HCC code?

Yes. I70.322 maps to Vascular Disease with Complications under the CMS-HCC V28 risk adjustment model (and Vascular Disease under V24).

HCC Category Mapping

V28HCC 264, Vascular Disease with Complications

0.356

V24HCC 108, Vascular Disease

0.297

ESRDHCC 108, Vascular Disease

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 I70.322

For I70.322to 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 I70.322 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

I70.322 is the ICD-10-CM diagnosis code for atherosclerosis of unspecified type of bypass graft(s) of the extremities with rest pain, left leg. Hardening and narrowing of a bypass graft in the left leg causing pain even at rest, indicating severe circulation problems. I70.322 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, I70.322 maps to Vascular Disease with Complications (HCC 264) with a community, non-dual, aged base RAF weight of 0.356. Under the older CMS-HCC V24 model, I70.322 maps to Vascular Disease (HCC 108) with a community, non-dual, aged base RAF weight of 0.297. 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 left leg location and rest pain component. Because I70.322 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 I70.322 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify documentation specifies left leg location and rest pain component
•Confirm bypass graft type is truly unspecified; if type is documented (venous, arterial, nonautologous), use more specific code

Clinical Significance

Atherosclerosis of bypass graft(s) with rest pain indicates critical limb ischemia (Fontaine Stage III/Rutherford Category 4), where blood flow is insufficient even at rest. This represents a limb-threatening condition requiring urgent vascular evaluation and intervention to prevent progression to tissue loss or gangrene. Capturing this code accurately reflects disease severity that demands higher levels of care and resource allocation.

Documentation Requirements

✓Clinical diagnosis of peripheral atherosclerosis explicitly documented by the provider
✓Specification of the affected vessel type (bypass graft(s))
✓Laterality clearly documented (left leg)
✓Documentation of rest pain — ischemic pain occurring at rest, typically in the forefoot, worsening with elevation and improving with dependency
✓Vascular assessment findings such as ankle-brachial index (ABI), pulse examination, or imaging results supporting the diagnosis
✓Current treatment plan including medication management, pain control, and any planned vascular interventions
✓Documentation distinguishing rest pain from claudication (exertional pain) or neuropathic pain
✓Documentation of prior bypass graft surgery with type of graft if known (autologous vein, nonnautologous biological, or nonbiological — code to specific graft type when documented)

Commonly Confused Codes

•I70.2xx (native artery series): Use I70.2xx when atherosclerosis involves the native arteries rather than a bypass graft; do not use bypass graft codes without documentation of prior graft surgery
•I70.311-I70.319 (bypass graft with intermittent claudication): Claudication is exertional pain relieved by rest; rest pain indicates more severe critical limb ischemia
•I70.331-I70.35 (bypass graft with ulceration): If ulceration is present along with rest pain, code the ulceration as it represents greater tissue compromise
•I70.361-I70.369 (bypass graft with gangrene): Gangrene codes supersede rest pain codes when tissue necrosis is documented
•I70.401-I70.499, I70.501-I70.599, I70.601-I70.699 (specific graft type codes): When the type of bypass graft is documented (autologous vein, nonnautologous biological, or nonbiological), code to the specific graft type rather than unspecified