Coding Interventional Radiology: Lower Extremity Area

By Michele Arias, RHIT, CCS, CIRCC

Interventional radiology is a challenging area for many coding professionals—and understandably so. This article discusses the basics of lower extremity revascularization, focusing on the territories, catheter placements, and interventions.

Three Territories for Lower Extremity

The lower extremity has three territories. The first is the iliac, consisting of the common, internal, and external iliac arteries. The second is the femoral/popliteal (fem/pop), which has the common femoral, profunda femoral, superficial femoral, and popliteal arteries. The third territory is the tibia/peroneal, which includes the anterior tibia, posterior tibia, and peroneal arteries.

Selective versus Non-Selective Catheter Placement(s)

Catheters are placed both selectively and non-selectively. What is the difference? For selective catheter placements, the documentation has to say “selective;” the catheter “cannulated,” “went into,” or was “parked” in the artery. Without that documentation, there is no support to code one of the selective catheter placement codes (CPT 36245, 36246, 36247, and, sometimes, add-on code 36248).

Insertion of a catheter into the aorta is considered non-selective. The catheter can “enter” the aorta, but it is considered a non-selective vessel. When the documentation shows that the catheter placement was only in the aorta, the non-selective catheter placement CPT code 36200 is coded. Once the catheter is placed into a selective artery, the non-selective code is removed and bundled in with the highest selected catheter placement.

Orders for Selective Catheter Placements

There are three orders for selective catheter placements: first, second, and third order (CPT 36245, 36246, 36247, and sometimes 36248). When the documentation states the catheter went into a 3rd order vascular family (CPT 36247), any non-selective codes (36200), first order (36245), and second order (36246) are bundled in with CPT 36247 on the ipsilateral side (same side as catheter placement).

If there are additional catheter placements on the contralateral (opposite) side, then a coding professional would code the catheter placement with an appropriate modifier (-LT/-RT/-50).

Consider this example: Documentation shows a selective catheter placement in the left common iliac (CPT 36245), a first order selective catheter placement, followed by selective catheter placement in the left common femoral artery (CPT 36246), a second order catheter placement. Following the guidance above, code to the highest catheter order placement. Since CPT 36246 is second order and 36245 is a first order, CPT 36245 is bundled in with 36246, so a coding professional would report 36246-LT.

Where does CPT 36248 come in when there are only three orders for selective catheter placements? CPT 36248 is an add-on code that is used when there are additional catheter placements beyond a third order placement. For example, a catheter is placed in the superficial femoral artery (SFA) (CPT 36247), followed by a catheter placement in the anterior tibial artery. The anterior tibial artery is also a third order catheter placement, but one cannot code CPT 36247 more than once for each lower extremity. To capture the additional work, code CPT 36247 and add-on code 36248.

Lower Extremity Interventions

When the angiogram shows a stenosis/occlusion, a decision could be made to do an intervention: angioplasty, stent placement, and/or athrectomy. Interventions are coded based on the hierarchy as follows: stent with athrectomy supersedes athrectomy; athrectomy supersedes stent; stent supersedes angioplasty. Angioplasty (pre- and post-procedure) is bundled in the athrectomy and stent insertions in the femoral/popliteal and tibia/peroneal territories, but coded separately for the iliac territory when an athrectomy is performed.

HCPCS code 0238T is coded for athrectomies in the iliacs, which can be coded up to three times per side since the guideline advises coding professionals that an intervention can be coded for each iliac artery. When there is an athrectomy and angioplasty in the internal iliac artery, code 37220 and 0238T; for athrectomy with stent insertion in the ipsilateral external iliac artery, code +37223 and 0238T.

When there are intervention(s) in the iliacs, code the base code and up to two add-on codes for each additional intervention on the ipsilateral side. That same guideline is followed in the tibia/peroneal area. For the femoral/popliteal territory, when an intervention is performed on any of the four arteries, only one CPT code can be coded, and it is based on the hierarchy as mentioned above.

Selective catheter placements are bundled in with lower extremity interventions. The exception to this is when an athrectomy (0238T) in the iliac artery/arteries is the only procedure(s) performed for the entire lower extremity.

Let’s start with iliacs. Revascularization in the iliacs has five CPT codes: two primary/base codes (37220/37221), two add-on codes, (+37222/+37233), and 0238T. For this example, documentation reflects the patient had a percutaneous transluminal angioplasty (PTA) in the left internal iliac and a PTA with stent placement in the ipsilateral external iliac. A coding professional would code CPT 37221-LT (Revascularilization, endovascular, open or percutaneous, iliac artery, unilateral, initial vessel, with transcatheter stent placement, includes angioplasty within same vessel; when performed) followed by +37222-LT (Revascularization, endovascular, open or percutatneous, iliac artery, each additional ipsilateral iliac vessel; with transluminal angioplasty) (List separately in addition to coding for primary procedure).

For the tibia/peroneal area, there are four primary/base codes (37228, 37229, 37230, and 37231) and four add-on codes (+37232, +37233, +37234, and +37235).

Consider the following example: The patient had a PTA in the right peroneal artery, a stent/PTA in the right posterior tibial artery, and an athrectomy with stent placement/PTA in the right anterior tibial artery. Based on the hierarchy, one would code CPT 37231-RT (Revascularization, endovascular, open or percutaneous, tibial, peroneal artery, unilateral, initial vessel with transluminal stent placement and athrectomy; includes angioplasty within the same vessel; when performed for the athrectomy with stent placement/PTA in the anterior tibial artery). Code +37234-RT (Revascularization, endovascular, open or percutaneous, tibial/peroneal artery with transluminal stent placement; includes angioplasty within the same vessel; when performed) (List separately in addition to primary procedure) for the stent/PTA in the posterior tibial artery. Within this territory, there was also a PTA in the peroneal artery, so the coding professional would also report add-on code +37232-RT (Revascularization, endovascular, open or percutaneous, tibia/peroneal artery, unilateral; each additional vessel with transluminal angioplasty) (List separately in addition to code for primary procedure).

The final territory is the femoral/popliteal. It does not matter if there are interventions in all four arteries within this area, a coding professional should only report one CPT code.

For this example, the documentation shows the interventions on the left leg were an athrectomy in the popliteal, stent and angioplasty in the SFA, and only an angioplasty in the common femoral. The one CPT to be reported is CPT 37227-LT (Revascularization, endovascular, open or percutaenous, femoral/popliteal artery(s), unilateral with transluminal stent placement(s) and athrectomy, includes angioplasty within the same vessel; when performed).

Catheter Placements and Interventions

Let’s put it all together with catheter placements and interventions. As discussed earlier, whenever catheters are placed and then a decision is made to do an intervention, the catheter placements (selective and non-selective) are not coded separately, as they are bundled with the intervention CPT code(s).

For this example, the RS&I (70000) code(s) will not be discussed. Reason for exam: the patient is having left lower extremity pain and scheduled for an aortogram and left lower extremity angiogram with possible intervention.

For the procedure, the left common femoral artery was percutaneously entered and a catheter was placed in the aorta (CPT 36200), and contrast was injected for the aortogram. The catheter was then cannulated in the left common iliac and a left lower extremity angiogram was performed (remove CPT 36200 and add CPT 36245-LT). The angiogram showed a 60 percent stenosis in the SFA. The catheter was then changed and parked in the superficial femoral artery (remove CPT 36245-LT and add CPT 36247-LT) contrast was injected, and a subsequent angiogram showed 85 percent stenosis in the anterior tibial artery.

The decision was made to do a stent placement/angioplasty in the SFA and athrectomy/stent/angioplasty in the anterior tibial artery. Since an intervention is being performed, CPT 36247-LT for the catheter placement in the SFA is bundled in with the intervention CPT codes.

CPT codes to be reported are 37231-LT for the athrectomy/stent/angioplasty in the anterior tibial artery, and 37226-LT for the stent placement/angioplasty in the SFA.

Interventional radiology is the future and coding professionals will be seeing more and more procedures turning this route. Interventional radiology coding is complex, but with practice and determination, it is a very rewarding specialty in which to be a coding professional.


American Medical Association. CPT 2018 Professional. Chicago, IL: AMA, 2018.

Zielske, David R. Interventional Radiology Coding Reference, Fourteenth Edition. ZHealth Publishing, 2017.

Michele Arias ( is senior outpatient coder at University of Miami Hospital.