HCPCS Level II code C9728 represents the placement of interstitial devices used for radiation therapy or surgical guidance—such as fiducial markers or dosimeters—when performed at sites other than the abdomen, pelvis, prostate, retroperitoneum, or thorax. The code captures procedures where devices are implanted by any approach and may cover single or multiple sites. This service is relevant nationally for radiology, radiation oncology, surgical, and ambulatory care billing and care coordination.

Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of what the code denotes, typical service locations, and the clinical context in which interstitial guidance devices are used. The publication outlines coding benchmarks, payer coverage patterns where available, and operational considerations for billing and documentation. It also highlights common modifier uses and areas where payers often request additional documentation (Data not available in the input). The content equips revenue cycle, clinical, and compliance teams with the essential coding description and national-level context necessary to align clinical documentation and claims submission for services represented by C9728.