I70.403 Unspecified atherosclerosis of autologous vein bypass graft(s) of the extremities, bilateral legs

ICD-10-CM I70.403: Unspecified atherosclerosis of autologous vein bypass graft(s) of the extremities, bilateral legs

ICD-10-CM code I70.403 identifies an unspecified atherosclerotic disease affecting autologous vein bypass grafts in both legs. This diagnostic concept represents a specific type of arterial disease documented within official terminology records and billing articles, serving as an active classification for this vascular condition. 1 5

Plain-language overview

Code I70.403 designates an unspecified atherosclerosis of autologous vein bypass grafts located in the extremities, specifically affecting both legs simultaneously. 1

What this code represents

The concept I70.403 is categorized semantically as a disease or syndrome and is an active terminology record with narrower child concepts within the ICD-10-CM system. 1

Within the coding hierarchy, I70.403 is a direct child of the parent concept I70.40, which denotes unspecified atherosclerosis of autologous vein bypass grafts of the extremities. 1

Clinical context

Vein grafts used in lower limb bypass procedures face long-term patency challenges due to accelerated atherosclerotic rates compared to native arteries, potentially leading to graft failure. 2

Documentation considerations

The official terminology record includes a published abbreviation for this concept: unsp athscl autol vein bypass of the extrm, bilateral legs, which may appear in coding tools. 1

Coverage and utilization context

The code I70.403 appears in Medicare billing and coding articles concerning non-invasive peripheral arterial vascular studies, indicating its use in administrative billing contexts. 5

What the sources add

While the National Cancer Institute record provides the official code definition, the Medicare article establishes its operational appearance within billing frameworks for vascular studies. 1 5

A university phecode mapping resource lists I70.403 among a broader spectrum of bilateral leg bypass graft atherosclerosis codes, distinguishing unspecified autologous vein grafts from other variants. 3

Questions to verify

The supplied sources do not establish whether I70.403 is considered a billable specific code or what specific clinical documentation elements are required to support its submission. 1 5

Sources

1. ICD-10-CM I70.403 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Phecode 440 · ExPRSweb — csg.sph.umich.edu; accessed 2026-07-27.
4. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-27.
5. Article - Billing and Coding: Non-Invasive Peripheral Arterial Vascular Studies (A57593) — cms.gov; accessed 2026-07-27.
6. Article - Billing and Coding: Cardiology Non-emergent Outpatient Stress Testing (A56423) — cms.gov; accessed 2026-07-27.