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CPT 33866: Aortic Arch Graft Placement with Circulatory Arrest

CPT code 33866 captures an intraoperative component of complex aortic arch reconstruction: placement of a graft in an aortic arch segment that extends beneath one or more arch vessels with isolation and control of those vessels under total circulatory arrest and/or isolated cerebral perfusion. Nationally, this code identifies high-acuity cardiothoracic and vascular procedures that carry significant operative risk and resource utilization, and it is reported in addition to the primary procedural code.

Key payers in the scope of national coverage and billing review include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a focused overview of clinical context for use of CPT code 33866, common billing practices related to reporting it alongside primary vascular procedure codes, and where available, benchmark and policy considerations relevant to high-complexity aortic arch interventions. The publication highlights procedure setting and service type, clarifies reporting intent of the code, and outlines areas where payer policy and reimbursement language commonly intersect with surgical documentation and coding. Data not available in the input is noted where applicable.

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Billing Code Overview

CPT code 33866 describes a technique performed during a primary vascular procedure in which a graft is placed in a segment of the aortic arch that extends beneath one or more arch vessels. The procedure includes isolating and controlling blood flow of the arch vessels while the patient is under total circulatory arrest and/or isolated cerebral perfusion. This code is reported in addition to the code for the primary vascular procedure.

Service type: Intraoperative aortic arch grafting with circulatory arrest/isolated cerebral perfusion

Typical site of service: Hospital operating room (cardiothoracic or vascular surgery setting)

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CPT 33866: Aortic Arch Graft Placement with Circulatory Arrest

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Billing Code Overview

Service type: Intraoperative aortic arch grafting with circulatory arrest/isolated cerebral perfusion

Typical site of service: Hospital operating room (cardiothoracic or vascular surgery setting)

Clinical & Coding Specifications

Clinical Context

A 68-year-old male with a degenerative thoracic aortic aneurysm involving the proximal descending thoracic aorta and the distal aortic arch is scheduled for an open ascending aortic and arch graft replacement. The surgical team plans a primary vascular procedure (for example, replacement of the ascending aorta and proximal arch) and anticipates the need to place a graft segment that extends beneath one or more arch vessels (innominate, left common carotid, left subclavian). During the operation the patient will be placed on cardiopulmonary bypass with periods of total circulatory arrest and isolated cerebral perfusion to allow safe isolation and control of the arch vessels while the graft is sutured into the arch.

The clinical workflow includes preoperative imaging (CT angiography of the chest), pre-op anesthesia and arterial line placement, median sternotomy and exposure of the aortic root and arch, institution of cardiopulmonary bypass, cooling to target temperature, period(s) of antegrade or retrograde cerebral perfusion with total circulatory arrest while the surgeon controls the arch vessels, placement of the arch graft under/around arch branches, re-establishment of flow, rewarming, hemostasis, and transfer to ICU for postoperative monitoring. Billing: report 33866 in addition to the primary aortic procedure code for the graft replacement when the graft extends under arch vessels and arch vessel isolation and control with total circulatory arrest and/or isolated cerebral perfusion are performed.

Coding Specifications

Modifier	Description	When to Use
`62`	Two surgeons	Use when two surgeons with distinct surgical roles operate together on the same day for shared responsibility of a complex aortic arch graft procedure.
`63`	Procedure performed on infants or neonates (age-based)	Not typically used for adults; include only when patient age meets criteria.
`66`	Surgical team	When a documented surgical team (multiple surgeons) bills for defined team procedures in complex open arch reconstructions.
`78`	Return to OR for related procedure during postoperative global period	Use if the patient requires an immediate return to the operating room for a related complication from the arch graft.
`79`	Unrelated procedure or service by the same physician during the postoperative period	Use if an unrelated procedure is performed during the global period.
`80`	Assistant surgeon	Use when a surgical assistant participates and documentation supports assistant services for the open arch graft.
`81`	Minimum assistant surgeon	Use if a minimum assistant is documented and payer allows payment for that role.
`82`	Assistant surgeon (when qualified resident unavailable)	Use when a qualified resident is unavailable and an assistant is required.
`99`	Multiple modifiers	Use when multiple informational modifiers not listed elsewhere need to be appended and payer accepts `99`.
`AS`	Physician assistant, nurse practitioner, or clinical nurse specialist services with direct supervision by the physician	Use when an advanced practice clinician provides substantial physician-level services per payer rules in the perioperative period.
`22`	Increased procedural services	Use when the work required is substantially greater than typical (extensive dissection or prolonged circulatory arrest) and documentation supports increased work.
`23`	Unusual anesthesia	Use when significant additional anesthesia is required due to complexity (broad physiologic derangements requiring non-routine anesthesia management).
`50`	Bilateral procedure	Rarely applicable; use only if bilateral anatomic operations are being reported and documentation supports bilateral designation.
`52`	Reduced services	Use when the procedure is partially reduced or not completed and documentation supports partial performance.

Taxonomy Code	Specialty	Notes
`337300000X`	Cardiovascular Surgeon (Cardiac)	Primary specialty performing open aortic arch grafting and circulatory arrest procedures.
`207R00000X`	Vascular Surgery	Vascular surgeons perform complex aortic arch repairs in select centers collaborating with cardiac surgery.
`2080P0005X`	Thoracic Surgery	Thoracic surgeons with cardiac training involved in complex arch reconstructions at some centers.
`163W00000X`	Physician Assistant	Common perioperative provider assisting in preoperative and postoperative management.
`207L00000X`	Interventional Cardiologist	May be involved in hybrid procedures and preoperative endovascular planning.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I71.2`	Thoracic aortic aneurysm, ruptured	Indicates a life-threatening aneurysm of the thoracic aorta that may require emergent open aortic and arch graft repair using circulatory arrest.
`I71.3`	Thoracic aortic aneurysm, without rupture	Elective or symptomatic aneurysm involving the arch that prompts surgical graft placement extending beneath arch vessels.
`I71.01`	Dissection of ascending aorta	Acute aortic dissection involving the ascending aorta and arch often necessitating complex grafting with arch vessel control and circulatory arrest.
`I71.02`	Dissection of thoracic aorta, unspecified site	Dissections affecting the arch may require arch grafting and cerebral perfusion strategies.
`I71.9`	Aortic aneurysm, unspecified	General aortic aneurysm diagnosis that may include arch involvement requiring open repair and arch grafting.
`I77.9`	Disorder of artery, unspecified	Non-specific arterial pathology that in rare cases may be associated with complex aortic surgical interventions.
`Z48.21`	Encounter for aftercare following surgical procedure of the circulatory system	Postoperative follow-up code used during the recovery period after open aortic arch graft surgery.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`33860`	Replacement, ascending aorta, with cardiopulmonary bypass, with or without valve repair/replacement	Primary procedure often billed for replacement of the ascending aorta; `33866` is reported in addition when arch graft extends beneath arch vessels and arch vessel control with circulatory arrest is performed.
`33863`	Replacement, aortic arch, with cardiopulmonary bypass, with or without valve repair/replacement, including reimplantation of arch vessels	Represents arch replacement procedures; `33866` is an add-on when the graft extends under arch vessels requiring isolation/control with circulatory arrest or isolated cerebral perfusion.
`33864`	Complex replacement of aortic arch with reimplantation of arch vessels, including partial or total arch reconstruction	Commonly performed in conjunction with arch grafting; `33866` is reported in addition to primary arch reconstruction codes when criteria met.
`33999`	Unlisted procedure, cardiothoracic surgery	Used when a specific arch-related service cannot be reported by existing codes; not preferred when `33866` and primary codes apply.
`33249`	Temporary transvenous pacing, insertion, replacement, repositioning, and removal when performed	May be performed perioperatively for arrhythmia management in complex aortic surgery and billed separately when applicable.

CPT 33858: Aortic Dissection Repair with Graft and Cardiopulmonary Bypass

CPT-33859-ASCENDING-AORTIC-ANEURYSM-REPAIR-WITH-GRAFT-BYPASS

CPT 33859: Ascending Aortic Aneurysm Repair with Graft and Bypass

CPT-33863-AORTIC-ROOT-PROXIMAL-ASCENDING-AORTA-REPLACEMENT-VALVE-CONDUIT

CPT 33863: Aortic Root and Proximal Ascending Aorta Replacement with Valve Conduit

CPT-33864-AORTIC-ROOT-AND-ASCENDING-AORTA-REPLACEMENT-WITH-VALVED-GRAFT

CPT 33864: Aortic Root and Proximal Ascending Aorta Replacement with Valved Graft

CPT-33871-AORTIC-ARCH-REPAIR-SYNTHETIC-GRAFT-CEREBRAL-ISOLATION

CPT 33871: Aortic Arch Repair with Synthetic Graft and Cerebral Isolation

CPT-33875-DESCENDING-THORACIC-AORTA-REPLACEMENT-GRAFT

CPT 33875: Descending Thoracic Aorta Replacement with Graft

CPT-33877-THORACOABDOMINAL-AORTIC-REPAIR-WITH-GRAFT

CPT 33877: Thoracoabdominal Aortic Repair with Graft

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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Clinical & Coding Specifications

Clinical Context

Coding Specifications

Modifier	Description	When to Use
`62`	Two surgeons	Use when two surgeons with distinct surgical roles operate together on the same day for shared responsibility of a complex aortic arch graft procedure.
`63`	Procedure performed on infants or neonates (age-based)	Not typically used for adults; include only when patient age meets criteria.
`66`	Surgical team	When a documented surgical team (multiple surgeons) bills for defined team procedures in complex open arch reconstructions.
`78`	Return to OR for related procedure during postoperative global period	Use if the patient requires an immediate return to the operating room for a related complication from the arch graft.
`79`	Unrelated procedure or service by the same physician during the postoperative period	Use if an unrelated procedure is performed during the global period.
`80`	Assistant surgeon	Use when a surgical assistant participates and documentation supports assistant services for the open arch graft.
`81`	Minimum assistant surgeon	Use if a minimum assistant is documented and payer allows payment for that role.
`82`	Assistant surgeon (when qualified resident unavailable)	Use when a qualified resident is unavailable and an assistant is required.
`99`	Multiple modifiers	Use when multiple informational modifiers not listed elsewhere need to be appended and payer accepts `99`.
`AS`	Physician assistant, nurse practitioner, or clinical nurse specialist services with direct supervision by the physician	Use when an advanced practice clinician provides substantial physician-level services per payer rules in the perioperative period.
`22`	Increased procedural services	Use when the work required is substantially greater than typical (extensive dissection or prolonged circulatory arrest) and documentation supports increased work.
`23`	Unusual anesthesia	Use when significant additional anesthesia is required due to complexity (broad physiologic derangements requiring non-routine anesthesia management).
`50`	Bilateral procedure	Rarely applicable; use only if bilateral anatomic operations are being reported and documentation supports bilateral designation.
`52`	Reduced services	Use when the procedure is partially reduced or not completed and documentation supports partial performance.

Taxonomy Code	Specialty	Notes
`337300000X`	Cardiovascular Surgeon (Cardiac)	Primary specialty performing open aortic arch grafting and circulatory arrest procedures.
`207R00000X`	Vascular Surgery	Vascular surgeons perform complex aortic arch repairs in select centers collaborating with cardiac surgery.
`2080P0005X`	Thoracic Surgery	Thoracic surgeons with cardiac training involved in complex arch reconstructions at some centers.
`163W00000X`	Physician Assistant	Common perioperative provider assisting in preoperative and postoperative management.
`207L00000X`	Interventional Cardiologist	May be involved in hybrid procedures and preoperative endovascular planning.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I71.2`	Thoracic aortic aneurysm, ruptured	Indicates a life-threatening aneurysm of the thoracic aorta that may require emergent open aortic and arch graft repair using circulatory arrest.
`I71.3`	Thoracic aortic aneurysm, without rupture	Elective or symptomatic aneurysm involving the arch that prompts surgical graft placement extending beneath arch vessels.
`I71.01`	Dissection of ascending aorta	Acute aortic dissection involving the ascending aorta and arch often necessitating complex grafting with arch vessel control and circulatory arrest.
`I71.02`	Dissection of thoracic aorta, unspecified site	Dissections affecting the arch may require arch grafting and cerebral perfusion strategies.
`I71.9`	Aortic aneurysm, unspecified	General aortic aneurysm diagnosis that may include arch involvement requiring open repair and arch grafting.
`I77.9`	Disorder of artery, unspecified	Non-specific arterial pathology that in rare cases may be associated with complex aortic surgical interventions.
`Z48.21`	Encounter for aftercare following surgical procedure of the circulatory system	Postoperative follow-up code used during the recovery period after open aortic arch graft surgery.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`33860`	Replacement, ascending aorta, with cardiopulmonary bypass, with or without valve repair/replacement	Primary procedure often billed for replacement of the ascending aorta; `33866` is reported in addition when arch graft extends beneath arch vessels and arch vessel control with circulatory arrest is performed.
`33863`	Replacement, aortic arch, with cardiopulmonary bypass, with or without valve repair/replacement, including reimplantation of arch vessels	Represents arch replacement procedures; `33866` is an add-on when the graft extends under arch vessels requiring isolation/control with circulatory arrest or isolated cerebral perfusion.
`33864`	Complex replacement of aortic arch with reimplantation of arch vessels, including partial or total arch reconstruction	Commonly performed in conjunction with arch grafting; `33866` is reported in addition to primary arch reconstruction codes when criteria met.
`33999`	Unlisted procedure, cardiothoracic surgery	Used when a specific arch-related service cannot be reported by existing codes; not preferred when `33866` and primary codes apply.
`33249`	Temporary transvenous pacing, insertion, replacement, repositioning, and removal when performed	May be performed perioperatively for arrhythmia management in complex aortic surgery and billed separately when applicable.

CPT 33858: Aortic Dissection Repair with Graft and Cardiopulmonary Bypass

CPT-33859-ASCENDING-AORTIC-ANEURYSM-REPAIR-WITH-GRAFT-BYPASS

CPT 33859: Ascending Aortic Aneurysm Repair with Graft and Bypass

CPT-33863-AORTIC-ROOT-PROXIMAL-ASCENDING-AORTA-REPLACEMENT-VALVE-CONDUIT

CPT 33863: Aortic Root and Proximal Ascending Aorta Replacement with Valve Conduit

CPT-33864-AORTIC-ROOT-AND-ASCENDING-AORTA-REPLACEMENT-WITH-VALVED-GRAFT

CPT 33864: Aortic Root and Proximal Ascending Aorta Replacement with Valved Graft

CPT-33871-AORTIC-ARCH-REPAIR-SYNTHETIC-GRAFT-CEREBRAL-ISOLATION

CPT 33871: Aortic Arch Repair with Synthetic Graft and Cerebral Isolation

CPT-33875-DESCENDING-THORACIC-AORTA-REPLACEMENT-GRAFT

CPT 33875: Descending Thoracic Aorta Replacement with Graft

CPT-33877-THORACOABDOMINAL-AORTIC-REPAIR-WITH-GRAFT

CPT 33877: Thoracoabdominal Aortic Repair with Graft

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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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.

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CPT 33866: Aortic Arch Graft Placement with Circulatory Arrest

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Billing Code Overview

OpenPayer

CPT 33866: Aortic Arch Graft Placement with Circulatory Arrest

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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

CPT 33866: Aortic Arch Graft Placement with Circulatory Arrest

Sign up for cpt 33866 policy alerts

Billing Code Overview

CPT 33866: Aortic Arch Graft Placement with Circulatory Arrest

Sign up for cpt 33866 policy alerts

Billing Code Overview

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Related Diagnoses

Related CPT Codes

Related Codes

When should CPT 33866 be reported?

Can CPT 33866 be billed alongside other arch replacement codes, and which codes are most commonly related?

Which modifiers are commonly used with CPT 33866?

Which specialties and provider types commonly perform or support the service described by CPT 33866?

Which payers are referenced for coverage and reimbursement context for CPT 33866?

References

Clinical & Coding Specifications

Clinical Context

Coding Specifications

Related Diagnoses

Related CPT Codes

Related Codes

When should CPT 33866 be reported?

Can CPT 33866 be billed alongside other arch replacement codes, and which codes are most commonly related?

Which modifiers are commonly used with CPT 33866?

Which specialties and provider types commonly perform or support the service described by CPT 33866?

Which payers are referenced for coverage and reimbursement context for CPT 33866?

References