All radiologists and radiation oncologists provide medical services to patients every day with the full anticipation that these services will be appropriately reimbursed. Yet most take this process for granted. Few have even a rudimentary idea how the system works by which a coding mechanism and reimbursement schedule are developed and maintained for the vast array of services they provide. Clearly, this is not good business. You need not stay in the dark any longer! This article describes (1) the fundamental structure of reimbursement for radiology and radiation oncology services; (2) the multiple steps required as a new procedure advances from a research concept to the assignment of a code in the American Medical Association's Current Procedural Terminology; (3) the process by which the new procedure and code are assigned a reimbursement value in the Medicare Fee Schedule, which acts as the base for over 75% of current medical reimbursement; and (4) the maintenance of this system for existing procedures.