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CPT 35515: Subclavian-to-Vertebral Artery Bypass with Vein Graft

CPT code 35515 denotes a surgical arterial bypass in which a vein graft connects the subclavian artery to a portion of the vertebral artery to bypass an occlusion and re-establish vertebral circulation. The procedure is a specialized vascular revascularization intervention performed in an operating room, typically for patients with symptomatic vertebrobasilar ischemia or traumatic/occlusive lesions compromising vertebral artery inflow. Nationally, this code represents high-acuity vascular surgery with implications for surgical capacity, perioperative risk management, and payer coverage policies. Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for the procedure, guidance on common billing considerations, and where available, benchmark references and policy updates relevant to coverage and medical necessity. The publication outlines expected service settings, procedural components, and common modifiers used with the code. Data not available in the input is noted where applicable.

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Billing Code Overview

CPT code 35515 describes a surgical arterial bypass procedure in which the provider bypasses a blood vessel blockage by inserting a bypass graft that connects the subclavian artery to a portion of the vertebral artery using a vein graft. This procedure is a vascular surgical revascularization intended to restore blood flow to the vertebral circulation when proximal arterial occlusive disease or injury impairs perfusion.

Service type: Surgical arterial bypass using a vein graft
Typical site of service: Inpatient or hospital operating room setting for vascular surgery, often performed by vascular or cardiothoracic surgeons

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CPT 35515: Subclavian-to-Vertebral Artery Bypass with Vein Graft

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Get alerted when payer policies referencing 35515 are released or updated.

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Billing Code Overview

Service type: Surgical arterial bypass using a vein graft
Typical site of service: Inpatient or hospital operating room setting for vascular surgery, often performed by vascular or cardiothoracic surgeons

Clinical & Coding Specifications

Clinical Context

A typical patient is a 65-year-old male with symptomatic vertebrobasilar insufficiency caused by severe occlusive disease of the proximal vertebral artery and subclavian steal physiology. He reports recurrent dizziness, syncope-like episodes, and transient ischemic symptoms despite optimal medical therapy including antiplatelet agents and risk-factor control. Noninvasive imaging (CT angiography or duplex ultrasonography) and confirmatory digital subtraction angiography demonstrate a high-grade stenosis or occlusion of the vertebral artery origin not amenable to endovascular angioplasty/stenting due to anatomic considerations or prior failed attempts.

The vascular surgery or cardiothoracic surgery team schedules an open extra-anatomic bypass procedure: harvesting a suitable autogenous vein graft (commonly the great saphenous vein), exposing the subclavian artery proximally and the vertebral artery more distally, then creating an interposition graft anastomosis from the subclavian artery to the vertebral artery to re-establish antegrade vertebral flow. The procedure is performed in an operating room with general anesthesia, continuous neurovascular monitoring as indicated, and vascular surgical instrumentation. Typical perioperative workflow includes preoperative imaging review, anesthesia induction, graft harvest, arterial exposures, graft anastomoses, hemostasis, and postoperative ICU or step-down monitoring for neurologic status and limb perfusion.

Typical site of service: Inpatient operating room or major ambulatory surgical center when medically appropriate. Service type: Open vascular bypass surgery (extra-anatomic arterial bypass).

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier — standard descriptor	Use as the primary submission when no other applicable modifier is required
`11`	Normally scheduled service	Use when the procedure is performed as planned without complications altering complexity
`22`	Increased procedural services	Use when work or time substantially exceeds typical for the procedure (document justification)
`52`	Reduced services	Use when a portion of the procedure is intentionally not completed or partially performed
`53`	Discontinued procedure	Use when procedure is started but halted for patient-related or intraoperative reasons before completion
`62`	Two surgeons	Use when two surgeons of different specialties work together as primary surgeons throughout the procedure
`66`	Surgical team	Use when a surgical team approach is documented for complex procedures requiring multiple surgeons
`78`	Return to operating room for related procedure during global period	Use when an unplanned return to the OR for a related reason occurs during the global postoperative period
`80`	Assistant surgeon	Use when an assistant surgeon provides assistance and is separately reportable
`26`	Professional component	Use if reporting only the professional component of a related service (rare for this code)

Taxonomy Code	Specialty	Notes
2080S0004X	Vascular Surgery	Primary specialty performing open arterial bypass procedures
207L00000X	Thoracic Surgery	May perform when brachiocephalic or proximal subclavian exposures overlap thoracic structures
207XS0103X	Cardiac Surgery	Cardiac or cardiothoracic surgeons may perform complex arch or subclavian-vertebral reconstructions
2086S0123X	General Surgery	Some general surgeons with vascular fellowship experience perform peripheral/neck bypasses
363L00000X	Interventional Cardiology	Typically involved for preoperative angiography or hybrid procedures (consultative role)

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I65.2`	Occlusion and stenosis of vertebral artery	Direct indication for subclavian-to-vertebral bypass to restore vertebral artery inflow
`I70.219`	Atherosclerosis of native arteries of the extremities with unspecified site, intermittent claudication	Reflects systemic atherosclerotic disease contributing to vertebral/subclavian disease (often comorbid)
`G45.9`	Transient ischemic attack, unspecified	Symptom complex (dizziness, transient neurologic deficits) prompting revascularization to prevent stroke
`I73.9`	Peripheral vascular disease, unspecified	Indicates systemic peripheral arterial disease often coexisting with cerebrovascular occlusive disease
`I77.9`	Disorder of arteries and arterioles, unspecified	Non-specific arterial disease code that may be used when more specific coding is not available

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`93010`	Electrocardiogram, routine ECG with at least 12 leads; interpretation and report only	Preoperative cardiac evaluation and perioperative monitoring interpretation
`36140`	Arterial catheterization, percutaneous; non-selective, initial, any method	Diagnostic arterial access/angiography preceding open bypass when performing intraoperative angiography
`36147`	Arterial catheterization, open percutaneous, with diagnostic angiography, each vessel	Used for diagnostic angiography of great vessels in planning or hybrid procedures
`33533`	Coronary artery bypass, venous graft, single coronary venous graft	Example of autogenous vein graft harvesting technique; conceptually related graft use (different anatomic site)
`35301`	Graft, arterial; interposition, graft; extra-anatomic grafts	Related open arterial graft techniques and coding for arterial interposition grafting
`99100`	Anesthesia for patient of extreme age, under 1 year or over 70 years, requiring specific monitoring	Possible anesthesia add-on when elderly patient requires additional monitoring

CPT 35500: Upper-Extremity Vein Harvest for Bypass Conduit

CPT-35501-CAROTID-COMMON-TO-INTERNAL-ARTERY-BYPASS-GRAFT

CPT 35501: Carotid Common-to-Internal Artery Bypass Graft

CPT-35506-CAROTID-TO-SUBCLAVIAN-BYPASS-GRAFT

CPT 35506: Carotid-to-Subclavian Bypass Graft

CPT-35508-CAROTID-TO-VERTEBRAL-BYPASS-GRAFT

CPT 35508: Carotid-to-Vertebral Artery Bypass Graft

CPT-35509-CAROTID-TO-CAROTID-VEIN-BYPASS-GRAFT

CPT 35509: Carotid-to-Carotid Bypass with Vein Graft

CPT-35510-CAROTID-TO-BRACHIAL-ARTERY-BYPASS-VEIN-GRAFT

CPT 35510: Carotid-to-Brachial Artery Bypass with Vein Graft

CPT-35511-SUBCLAVIAN-ARTERY-TO-SUBCLAVIAN-ARTERY-VEIN-BYPASS

CPT 35511: Subclavian-to-Subclavian Vein Bypass Graft

CPT-35512-SUBCLAVIAN-TO-BRACHIAL-ARTERY-VEIN-BYPASS

CPT 35512: Subclavian-to-Brachial Artery Vein Bypass

CPT-35516-SUBCLAVIAN-TO-AXILLARY-VEIN-BYPASS

CPT 35516: Subclavian-to-Axillary Vein Bypass

CPT-35518-AXILLARY-ARTERY-TO-AXILLARY-ARTERY-BYPASS-VEIN-GRAFT

CPT 35518: Axillary-to-Axillary Artery Bypass with Vein Graft

Showing 1–10 of 32

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Jul 29, 2026.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Jul 29, 2026.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Jul 29, 2026.

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Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Clinical & Coding Specifications

Clinical Context

Typical site of service: Inpatient operating room or major ambulatory surgical center when medically appropriate. Service type: Open vascular bypass surgery (extra-anatomic arterial bypass).

Coding Specifications

Modifier	Description	When to Use
`00`	No modifier — standard descriptor	Use as the primary submission when no other applicable modifier is required
`11`	Normally scheduled service	Use when the procedure is performed as planned without complications altering complexity
`22`	Increased procedural services	Use when work or time substantially exceeds typical for the procedure (document justification)
`52`	Reduced services	Use when a portion of the procedure is intentionally not completed or partially performed
`53`	Discontinued procedure	Use when procedure is started but halted for patient-related or intraoperative reasons before completion
`62`	Two surgeons	Use when two surgeons of different specialties work together as primary surgeons throughout the procedure
`66`	Surgical team	Use when a surgical team approach is documented for complex procedures requiring multiple surgeons
`78`	Return to operating room for related procedure during global period	Use when an unplanned return to the OR for a related reason occurs during the global postoperative period
`80`	Assistant surgeon	Use when an assistant surgeon provides assistance and is separately reportable
`26`	Professional component	Use if reporting only the professional component of a related service (rare for this code)

Taxonomy Code	Specialty	Notes
2080S0004X	Vascular Surgery	Primary specialty performing open arterial bypass procedures
207L00000X	Thoracic Surgery	May perform when brachiocephalic or proximal subclavian exposures overlap thoracic structures
207XS0103X	Cardiac Surgery	Cardiac or cardiothoracic surgeons may perform complex arch or subclavian-vertebral reconstructions
2086S0123X	General Surgery	Some general surgeons with vascular fellowship experience perform peripheral/neck bypasses
363L00000X	Interventional Cardiology	Typically involved for preoperative angiography or hybrid procedures (consultative role)

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I65.2`	Occlusion and stenosis of vertebral artery	Direct indication for subclavian-to-vertebral bypass to restore vertebral artery inflow
`I70.219`	Atherosclerosis of native arteries of the extremities with unspecified site, intermittent claudication	Reflects systemic atherosclerotic disease contributing to vertebral/subclavian disease (often comorbid)
`G45.9`	Transient ischemic attack, unspecified	Symptom complex (dizziness, transient neurologic deficits) prompting revascularization to prevent stroke
`I73.9`	Peripheral vascular disease, unspecified	Indicates systemic peripheral arterial disease often coexisting with cerebrovascular occlusive disease
`I77.9`	Disorder of arteries and arterioles, unspecified	Non-specific arterial disease code that may be used when more specific coding is not available

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`93010`	Electrocardiogram, routine ECG with at least 12 leads; interpretation and report only	Preoperative cardiac evaluation and perioperative monitoring interpretation
`36140`	Arterial catheterization, percutaneous; non-selective, initial, any method	Diagnostic arterial access/angiography preceding open bypass when performing intraoperative angiography
`36147`	Arterial catheterization, open percutaneous, with diagnostic angiography, each vessel	Used for diagnostic angiography of great vessels in planning or hybrid procedures
`33533`	Coronary artery bypass, venous graft, single coronary venous graft	Example of autogenous vein graft harvesting technique; conceptually related graft use (different anatomic site)
`35301`	Graft, arterial; interposition, graft; extra-anatomic grafts	Related open arterial graft techniques and coding for arterial interposition grafting
`99100`	Anesthesia for patient of extreme age, under 1 year or over 70 years, requiring specific monitoring	Possible anesthesia add-on when elderly patient requires additional monitoring

CPT 35500: Upper-Extremity Vein Harvest for Bypass Conduit

CPT-35501-CAROTID-COMMON-TO-INTERNAL-ARTERY-BYPASS-GRAFT

CPT 35501: Carotid Common-to-Internal Artery Bypass Graft

CPT-35506-CAROTID-TO-SUBCLAVIAN-BYPASS-GRAFT

CPT 35506: Carotid-to-Subclavian Bypass Graft

CPT-35508-CAROTID-TO-VERTEBRAL-BYPASS-GRAFT

CPT 35508: Carotid-to-Vertebral Artery Bypass Graft

CPT-35509-CAROTID-TO-CAROTID-VEIN-BYPASS-GRAFT

CPT 35509: Carotid-to-Carotid Bypass with Vein Graft

CPT-35510-CAROTID-TO-BRACHIAL-ARTERY-BYPASS-VEIN-GRAFT

CPT 35510: Carotid-to-Brachial Artery Bypass with Vein Graft

CPT-35511-SUBCLAVIAN-ARTERY-TO-SUBCLAVIAN-ARTERY-VEIN-BYPASS

CPT 35511: Subclavian-to-Subclavian Vein Bypass Graft

CPT-35512-SUBCLAVIAN-TO-BRACHIAL-ARTERY-VEIN-BYPASS

CPT 35512: Subclavian-to-Brachial Artery Vein Bypass

CPT-35516-SUBCLAVIAN-TO-AXILLARY-VEIN-BYPASS

CPT 35516: Subclavian-to-Axillary Vein Bypass

CPT-35518-AXILLARY-ARTERY-TO-AXILLARY-ARTERY-BYPASS-VEIN-GRAFT

CPT 35518: Axillary-to-Axillary Artery Bypass with Vein Graft

Showing 1–10 of 32

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Jul 29, 2026.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Jul 29, 2026.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Jul 29, 2026.

Published by

Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

OpenPayer

CPT 35515: Subclavian-to-Vertebral Artery Bypass with Vein Graft

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Billing Code Overview

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CPT 35515: Subclavian-to-Vertebral Artery Bypass with Vein Graft

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Billing Code Overview

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Related Diagnoses

Related CPT Codes

Related Codes

References

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Related Diagnoses

Related CPT Codes

Related Codes

References