Treatment items need a referral for a course of treatment consistent with a treatment and management plan claimed under item 135, 289, 137 or 139 (or 92140, 92434, 92141, 92142), from the doctor who holds that plan; a separate referral for each practitioner; and a new referral for each course (up to 10 services, as allocated by the doctor). No benefit is paid until the plan item has been processed by Medicare.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.