HCPCS Level II code C2635 denotes a high-activity, non-stranded palladium-103 brachytherapy source (greater than 2.2 mCi, per source). These radioactive seeds are used in intraoperative or implant-based radiation therapies to deliver targeted dose to tumors while limiting exposure to surrounding healthy tissue. Nationally, payment and coverage for brachytherapy supplies like C2635 affect radiation oncology service lines, capital planning for oncology clinics, and cost considerations for procedures such as prostate brachytherapy and other localized tumor treatments.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise review of clinical context for palladium-103 high-activity sources, typical sites of service (hospital outpatient departments, ambulatory surgery centers, and radiation oncology clinics), and what to expect in payer coverage patterns. The publication outlines benchmark considerations, common billing modifiers and coding practice notes, and policy updates that influence reimbursement and claim adjudication. Where specific data points were not provided in the source input, the report indicates that those items are not available. This summary provides clinicians, billing professionals, and administrators a national-level primer on the use and billing considerations for HCPCS Level II code C2635.