Six Critical Tips for 2025 Thrombolysis Coding

As 2026 approaches, interventional radiology teams face mounting pressure from coding overhauls and tightening reimbursement rules—especially for complex procedures like catheter-directed thrombolysis. The storm of economic turbulence and uncertainty looming over 2026 makes IR coding especially vulnerable, with expert insight a necessary tool to tighten down accuracy and secure compliance. Thrombolysis, a life-saving therapy that dissolves dangerous clots directly within arteries or veins, involves multiple stages, prolonged infusions, and intricate documentation requirements. Even minor coding missteps could deliver major revenue losses and compliance consequences. Let’s cut through the complexity and prepare for the evolving thrombolysis coding landscape ahead.

Expert Tips in Action

1.) First, understand that codes 37211 and 37212 do NOT include catheterization, diagnostic angiograms, or other interventions. Codes for those services should only be added when appropriate. CPT® describes conditions for coding a diagnostic angiogram S&I during the same session as an intervention. Code 76937 for ultrasound guidance for vascular access may also be coded when performed and documented according to code description requirements. E&M visits to the patient on the day of, and related to, thrombolysis are included and not separately coded.

The following codes are assigned per calendar day and include all imaging and catheter repositioning and/or exchanges required on that day, regardless of how many times the patient is brought back for follow-up. Be aware that you should not assign 75898 for follow-up angiography during thrombolytic infusions.

2.) Coders should note that the thrombolysis codes are unilateral, so if bilateral thrombolysis is performed through separate accesses, add modifier 50 to the appropriate code. Modifiers continuously prove to be a challenging area for coders, resulting in widespread billing errors, so knowing how to apply the correct modifier is especially important. With that in mind, be careful that if two completely separate vascular beds, such as the renal artery and femoral artery, are treated, you should add modifier 59 to the appropriate thrombolysis codes.

Although not specifically noted in the CPT manual, when these codes were introduced during the CPT Symposium, AMA speakers indicated that these thrombolysis infusion codes are to be assigned for prolonged infusions: the patient must leave the treatment room with the infusion running.

3.) Be vigilant about the circumstances when the code should be not applied. Do not assign a thrombolysis infusion code for an injection of a thrombolytic agent during a mechanical thrombectomy procedure. Do not report the following codes for intracranial arterial thrombolysis, see code 61645 instead.

4.) When coding for thrombolysis, it’s important to know which codes to assign for different treatment scenarios. For the initiation of thrombolysis and any same-day follow-up evaluations, imaging, or catheter repositioning/exchanges, use codes 37211 or 37212. Code 37211 is specific to arterial thrombolysis, while 37212 is used for venous thrombolysis. If the procedure starts and finishes on the same day, you’ll only report the initial treatment day using the appropriate code. This distinction is key for ensuring accurate billing and documentation when managing thrombolysis cases.

5.) Under the circumstances a thrombolysis procedure lasts three or more days, each day except the initial day and the last day should be reported with code 37213. It may be assigned for either arterial or venous thrombolysis, and it includes any work related to the thrombolytic procedure on the same calendar day.

6.) The last day of a thrombolysis procedure is reported with code 37214. As with 37211, 37212, and 37213, this code is assigned per calendar day and includes any follow-up exams, catheter repositioning and/or exchanges. Removal of the catheter and closure of the access site are included in 37214.

 ⚠️ Your 2025 IR Coding Remains Under Threat, Creating Significant Risk to Your Bottom Line. These Are NOT All the Tips and Tricks Necessary for Success. 

With every dollar of reimbursement counting more than ever in the face of payment decline and complex changes, it’s imperative to make sure your CPT^® coding is correct and compliant. Master more coding topics and break down the complexity with our 2025 Venous Studies Interventional Radiology Coding live on October 15, 2025, or on demand past this date. This webcast is an essential training tool for both audio and visual learners.