CMS updated reimbursement rates for IMRT and SBRT delivery codes, revised medical necessity documentation requirements for image-guided procedures, and introduced stricter prior authorization protocols for high-cost treatment modalities under Medicare Advantage plans.

Radiation oncology billing covers treatment planning, simulation, dosimetry, IMRT and SBRT delivery, brachytherapy, image-guided radiation therapy, physician treatment management, physics consultations, and port film interpretation across both technical and professional billing components.

The 4 R’s are Repair of DNA damage, Redistribution of cells through the cell cycle, Repopulation of tumor cells between fractions, and Reoxygenation of hypoxic tumor regions. These principles directly guide fractionation decisions that billing must accurately reflect.

Common CPT codes include 77385 and 77386 for IMRT delivery, 77373 for SBRT, 77387 for IGRT, 77427 for treatment management, and 77301 for treatment planning. Code selection depends on modality, complexity, and documented clinical intent.

Reimbursement timelines vary by payer. Medicare typically processes clean claims within 14 to 30 days. Commercial payers average 30 to 45 days. Incomplete documentation or missing prior authorization can extend that timeline significantly.

The most common denial triggers include missing prior authorization for SBRT, insufficient medical necessity documentation, incorrect fraction unit counts under CPT 77427, and bundling errors between treatment delivery and image guidance codes submitted on the same date.