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Official Description

Coronary artery bypass, using venous graft(s) and arterial graft(s); 2 venous grafts (List separately in addition to code for primary procedure)

© Copyright 2025 American Medical Association. All rights reserved.

Common Language Description

Coronary artery bypass graft (CABG) is a surgical procedure aimed at improving blood flow to the heart by bypassing blocked or narrowed coronary arteries. This procedure is critical for patients suffering from ischemic heart disease, which can lead to serious conditions such as myocardial infarction (heart attack). The surgery involves the use of both venous and arterial grafts to create new pathways for blood to reach the heart muscle. Specifically, CPT® Code 33518 pertains to the use of two venous grafts in this bypass procedure. The coronary arteries are responsible for delivering oxygen-rich blood to the heart, and any obstruction in these arteries can significantly impair heart function. During the CABG procedure, surgeons typically harvest veins, often the greater saphenous veins from the legs, which are then prepared for grafting. The surgical process begins with an incision in the chest, followed by the division of the sternum and retraction of the ribs to gain access to the heart. Depending on the technique employed, the surgery may be performed using the off-pump coronary artery bypass (OPCAB) method, which allows the procedure to be conducted on a beating heart, or through cardiopulmonary bypass, where the heart is temporarily stopped and blood is rerouted through a machine. The prepared vein grafts are meticulously sewn into place, connecting one end to the ascending aorta and the other end to the coronary artery beyond the site of blockage. This procedure is essential for restoring adequate blood flow and alleviating symptoms associated with coronary artery disease.

© Copyright 2025 Coding Ahead. All rights reserved.

1. Indications

The coronary artery bypass graft (CABG) procedure, specifically coded as CPT® Code 33518, is indicated for patients with significant coronary artery disease characterized by the following conditions:

  • Ischemic Heart Disease - A condition where the heart muscle is deprived of oxygen due to narrowed or blocked coronary arteries.
  • Myocardial Infarction - A heart attack resulting from prolonged ischemia, necessitating surgical intervention to restore blood flow.
  • Severe Angina - Persistent chest pain or discomfort due to inadequate blood supply to the heart muscle, often prompting the need for bypass surgery.

2. Procedure

The CABG procedure utilizing CPT® Code 33518 involves several critical steps to ensure successful grafting of two venous grafts:

  • Harvesting of Veins - The procedure begins with the surgical harvesting of the greater saphenous veins from the patient's legs. These veins are selected for their suitability as grafts due to their size and ability to carry blood effectively.
  • Chest Incision - A median sternotomy is performed, which involves making a vertical incision down the center of the chest. The sternum is then divided to provide access to the heart.
  • Exposure of the Heart - The ribs are retracted to create a clear view of the heart, allowing the surgeon to assess the coronary arteries and plan the grafting procedure.
  • Cardiac Stabilization - Depending on the surgical technique, the procedure may be performed using the off-pump coronary artery bypass (OPCAB) method, where the heart continues to beat, or through cardiopulmonary bypass, which temporarily halts the heart's function while a machine takes over the circulation of blood.
  • Grafting Procedure - The prepared venous grafts are sewn into place. One end of each graft is attached to the ascending aorta, while the other end is connected to the coronary artery beyond the blockage, effectively rerouting blood flow around the obstructed area.

3. Post-Procedure

After the CABG procedure coded as CPT® Code 33518, patients typically require close monitoring in a recovery unit. Post-operative care includes managing pain, monitoring heart function, and ensuring proper healing of the surgical sites. Patients may be advised on lifestyle modifications and rehabilitation programs to support recovery and improve cardiovascular health. Follow-up appointments are essential to assess the success of the grafts and the overall health of the patient.

Short Descr CABG ARTERY-VEIN TWO
Medium Descr CORONARY ARTERY BYP W/VEIN & ARTERY GRAFT 2 VEIN
Long Descr Coronary artery bypass, using venous graft(s) and arterial graft(s); 2 venous grafts (List separately in addition to code for primary procedure)
Status Code Active Code
Global Days ZZZ - Code Related to Another Service
PC/TC Indicator (26, TC) 0 - Physician Service Code
Multiple Procedures (51) 0 - No payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 2 - Payment restriction for assistants at surgery does not apply to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Inpatient Procedures, not paid under OPPS
Type of Service (TOS) 2 - Surgery
Berenson-Eggers TOS (BETOS) P2A - Major procedure, cardiovascular-CABG
MUE 1
CCS Clinical Classification 44 - Coronary artery bypass graft (CABG)

This is an add-on code that must be used in conjunction with one of these primary codes.

33533 MPFS Status: Active Code APC C Physician Quality Reporting CPT Assistant Article Coronary artery bypass, using arterial graft(s); single arterial graft
33534 MPFS Status: Active Code APC C Physician Quality Reporting Coronary artery bypass, using arterial graft(s); 2 coronary arterial grafts
33535 MPFS Status: Active Code APC C Physician Quality Reporting Coronary artery bypass, using arterial graft(s); 3 coronary arterial grafts
33536 MPFS Status: Active Code APC C Physician Quality Reporting CPT Assistant Article Coronary artery bypass, using arterial graft(s); 4 or more coronary arterial grafts
33141 Addon Code MPFS Status: Active Code APC C Physician Quality Reporting PUB 100 CPT Assistant Article Transmyocardial laser revascularization, by thoracotomy; performed at the time of other open cardiac procedure(s) (List separately in addition to code for primary procedure)
33508 Addon Code MPFS Status: Active Code APC N ASC N1 Illustration for Code Endoscopy, surgical, including video-assisted harvest of vein(s) for coronary artery bypass procedure (List separately in addition to code for primary procedure)
33530 Addon Code MPFS Status: Active Code APC C Physician Quality Reporting CPT Assistant Article Illustration for Code Reoperation, coronary artery bypass procedure or valve procedure, more than 1 month after original operation (List separately in addition to code for primary procedure)
35500 Addon Code MPFS Status: Active Code APC N CPT Assistant Article Harvest of upper extremity vein, 1 segment, for lower extremity or coronary artery bypass procedure (List separately in addition to code for primary procedure)
35572 Addon Code MPFS Status: Active Code APC N ASC N1 CPT Assistant Article Illustration for Code Harvest of femoropopliteal vein, 1 segment, for vascular reconstruction procedure (eg, aortic, vena caval, coronary, peripheral artery) (List separately in addition to code for primary procedure)
AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
GC This service has been performed in part by a resident under the direction of a teaching physician
80 Assistant surgeon: surgical assistant services may be identified by adding modifier 80 to the usual procedure number(s).
82 Assistant surgeon (when qualified resident surgeon not available): the unavailability of a qualified resident surgeon is a prerequisite for use of modifier 82 appended to the usual procedure code number(s).
77 Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
CR Catastrophe/disaster related
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
AG Primary physician
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
Q6 Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
22 Increased procedural services: when the work required to provide a service is substantially greater than typically required, it may be identified by adding modifier 22 to the usual procedure code. documentation must support the substantial additional work and the reason for the additional work (ie, increased intensity, time, technical difficulty of procedure, severity of patient's condition, physical and mental effort required). note: this modifier should not be appended to an e/m service.
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
53 Discontinued procedure: under certain circumstances, the physician or other qualified health care professional may elect to terminate a surgical or diagnostic procedure. due to extenuating circumstances or those that threaten the well being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure was started but discontinued. this circumstance may be reported by adding modifier 53 to the code reported by the individual for the discontinued procedure. note: this modifier is not used to report the elective cancellation of a procedure prior to the patient's anesthesia induction and/or surgical preparation in the operating suite. for outpatient hospital/ambulatory surgery center (asc) reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
58 Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78.
62 Two surgeons: when 2 surgeons work together as primary surgeons performing distinct part(s) of a procedure, each surgeon should report his/her distinct operative work by adding modifier 62 to the procedure code and any associated add-on code(s) for that procedure as long as both surgeons continue to work together as primary surgeons. each surgeon should report the co-surgery once using the same procedure code. if additional procedure(s) (including add-on procedure(s) are performed during the same surgical session, separate code(s) may also be reported with modifier 62 added. note: if a co-surgeon acts as an assistant in the performance of additional procedure(s), other than those reported with the modifier 62, during the same surgical session, those services may be reported using separate procedure code(s) with modifier 80 or modifier 82 added, as appropriate.
78 Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period: it may be necessary to indicate that another procedure was performed during the postoperative period of the initial procedure (unplanned procedure following initial procedure). when this procedure is related to the first, and requires the use of an operating/procedure room, it may be reported by adding modifier 78 to the related procedure. (for repeat procedures, see modifier 76.)
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
81 Minimum assistant surgeon: minimum surgical assistant services are identified by adding modifier 81 to the usual procedure number.
AQ Physician providing a service in an unlisted health professional shortage area (hpsa)
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
KX Requirements specified in the medical policy have been met
LC Left circumflex coronary artery
LD Left anterior descending coronary artery
LT Left side (used to identify procedures performed on the left side of the body)
PD Diagnostic or related non diagnostic item or service provided in a wholly owned or operated entity to a patient who is admitted as an inpatient within 3 days
Q0 Investigational clinical service provided in a clinical research study that is in an approved clinical research study
RC Right coronary artery
RT Right side (used to identify procedures performed on the right side of the body)
UD Medicaid level of care 13, as defined by each state
X4 Episodic/focused services: for reporting services by clinicians who provide focused care on particular types of treatment limited to a defined period and circumstance; the patient has a problem, acute or chronic, that will be treated with surgery, radiation, or some other type of generally time-limited intervention; reporting clinician service examples include but are not limited to, the orthopedic surgeon performing a knee replacement and seeing the patient through the postoperative period
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
Date
Action
Notes
2013-01-01 Changed Medium Descriptor changed.
2011-01-01 Changed Short description changed.
2010-01-01 Changed Code description changed.
2008-01-01 Changed Code description changed.
1993-01-01 Added First appearance in code book in 1993.
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