I70.318 ICD-10-CM Code: Atherosclerosis of unspecified type of bypass graft(s) of the extremities with intermittent claudication, other extremity
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FY 2026 Apr update / Diseases of the circulatory system (I00-I99) / Diseases of arteries, arterioles and capillaries (I70-I79)
I70.318
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAtherosclerosis of unspecified type of bypass graft(s) of the extremities with intermittent claudication, other extremity
Plaque buildup in a bypass graft of an arm or other extremity (not the main leg arteries) causing pain or cramping during activity that improves with rest.
Buddy Insight
Atherosclerosis of bypass graft(s) without specification of rest pain, ulceration, or gangrene indicates peripheral arterial disease that may present with claudication or be asymptomatic.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
MappedHCC 108
RAF 0.297
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 108
RAF 0.0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for I70.318 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for I70.318 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for I70.318 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for I70.318 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for I70.318 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for I70.318 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for I70.318 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 I70.318 an HCC code?
Yes. I70.318 maps to Vascular Disease under the V24 model but is not retained in V28.
HCC Category Mapping
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 I70.318
For I70.318to 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 I70.318 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
I70.318 is the ICD-10-CM diagnosis code for atherosclerosis of unspecified type of bypass graft(s) of the extremities with intermittent claudication, other extremity. Plaque buildup in a bypass graft of an arm or other extremity (not the main leg arteries) causing pain or cramping during activity that improves with rest. I70.318 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 older CMS-HCC V24 model, I70.318 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.
Use this code for bypass grafts in upper extremities or other non-standard leg locations. Because I70.318 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 I70.318 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code for bypass grafts in upper extremities or other non-standard leg locations
- •Clearly document which extremity is affected and the claudication symptoms present
Clinical Significance
Atherosclerosis of bypass graft(s) without specification of rest pain, ulceration, or gangrene indicates peripheral arterial disease that may present with claudication or be asymptomatic. While less severe than limb-threatening ischemia, this condition requires ongoing monitoring, medical management, and cardiovascular risk factor modification to prevent disease progression. Proper documentation of the specific manifestations helps distinguish this from more severe peripheral arterial disease categories.
Documentation Requirements
- ✓Clinical diagnosis of peripheral atherosclerosis explicitly documented by the provider
- ✓Specification of the affected vessel type (bypass graft(s))
- ✓Laterality clearly documented (other extremity)
- ✓Description of symptoms (claudication, diminished pulses, skin changes) or notation of asymptomatic disease
- ✓Vascular assessment findings such as ankle-brachial index, pulse examination, or imaging
- ✓Current treatment plan including medications, lifestyle modifications, and surveillance schedule
- ✓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): Use when the specific symptom of exertional leg pain is documented
- •I70.321-I70.329 (bypass graft with rest pain): Use when ischemic pain at rest is documented, indicating more critical ischemia
- •I70.331-I70.35 (bypass graft with ulceration): Use when tissue breakdown is present
- •I70.401-I70.499, I70.501-I70.599, I70.601-I70.699 (specific graft type codes): Always code to the most specific graft type documented (autologous vein, nonnautologous biological, nonbiological)
- •I73.9 (Peripheral vascular disease, unspecified): Avoid when bypass graft atherosclerosis can be coded specifically