Analyzing Y-90 Brachytherapy Coding for Breakthrough Success

When it comes to radiation oncology coding, the clinical treatment planning process isn’t just technical—it’s critical, with complex nuances that may spell trouble for coders and compliance professionals alike. For procedures involving Y-90 radioembolization, there are key elements of planning that drive accurate code selection and reimbursement. This includes interpreting advanced imaging, localizing the tumor, determining treatment volume and dosage, selecting the right modality, and identifying appropriate treatment devices. As some professionals may know, institutions licensed to administer Y-90 must have an authorized user (AU) who is responsible for the pre-procedure dosimetry and treatment planning. SIRT is considered a brachytherapy procedure, and guidance from payors supports billing the associated clinical treatment planning by the physician at the complex level with 77263, but the documentation must appropriately meet the requirements for a complex treatment plan. We will explore the critical details for accurate understanding.

Back to the Basics of Radiation Clinical Treatment Planning

To support billing at the complex level with 77263, the authorized user (AU) must draw on several data sources when developing the treatment plan:

• angiographic studies
• cross-sectional imaging, prior treatments
• Tc99m-MAA scans
• and 3D reconstructed images

All contribute to determining the appropriate Y-90 dose and timing. Coders should pay special attention to documentation. It must clearly outline the treatment goals and detail specific dose parameters, including any constraints for the targeted area and nearby critical structures. Once it’s confirmed that the patient is a good candidate for SIRT using Y-90, the physician calculates the dose to be administered. This dose calculation is a distinct step and can be separately reported using CPT® 77300, provided the documentation includes patient-specific data to justify the calculation. Note that this is a separate service from the work outlined for the clinical treatment plan and can be billed in addition to code 77263.

Cracking Coding Nuances

First, any selective catheter placements are reportable using the appropriate codes (36245–36248). Coders should note that while the associated RS&I codes should not be routinely reported since angiography is confirmatory and considered to be part of the therapeutic procedure, there are exceptions. There are some key circumstances where these RS&I codes (75726 and 75774) may be reportable in the appropriate clinical setting, such as if pre-procedural documentation indicates suspicion of new vascular flow patterns or detrimental effect of an interval therapy on the vessels.

Under the circumstances where the IR physician is an authorized user (a one-physician model), coding for the Y-90 procedure is fairly straightforward. Once the target artery is selected, the physician delivers the Y-90 dose and reports it using CPT® code 37243 for tumor embolization and 79445 for the intra-arterial injection of the radiopharmaceutical. It’s important to note that 37243 includes all related RS&I services, as well as any additional embolizations performed during the same session, such as redirecting blood flow to protect nearby organs.

In some Y-90 workflows, coding responsibilities shift depending on how the procedure is performed—especially when two physicians are involved. For instance, if the interventional radiologist (IR) isn’t an Authorized User (AU), they must collaborate with a physician who is often someone from nuclear medicine or radiation oncology. In this setup, the AU takes on the responsibility for receiving, handling, and storing the Y-90 dose, all in compliance with Nuclear Regulatory Commission (NRC) regulations, and ensures proper documentation of those tasks. Meanwhile, the IR physician focuses on reporting the catheter placement codes (36245–36248), any relevant angiographic supervision and interpretation codes (75726 and/or 75774), and the embolization code 37243. The AU, on the other hand, reports the planning, dosimetry, and administration work—potentially including code 79445 for the intra-arterial injection. Pay special attention to documentation. It should clearly define who did what and verify that all roles are properly supported.

Coding for the injection of Y-90 may also vary by payor. For example, the Blue Cross Blue Shield (BCBS) plans utilize HCPCS codes which begin with “S” for some procedures. HCPCS S2095 may be required by a BCBS payor; however, this code is not accepted by Medicare and many other payors. Providers who perform radioembolization should verify the preferred code assignment with the patient’s payor prior to the procedure and obtain preauthorization for the treatment whenever possible.

Be aware that The Y-90 source is not billed by the physician but is billed by the facility. It is important to note that the brachytherapy source is reported on the claim appropriately with HCPCS code C2616 in a quantity of one (1) for the entire vial.

⚠ Your 2025 Nuclear Medine 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 in our Radiopharmaceutical & Brachytherapy Coding: Master the 2025 OPPS Changes and Avoid Costly Errors on July 23, 2025 at 11:30 am CT.