down·code / ˈdounˌkōd/ • v. [tr./syntax>.] 1. designate (a medical procedure or insurance claim) with a lower value: an insurer who systematically downcodes professional charge submissions for critical care services [intr.] we cannot turn to Medicaid to pay if Medicare downcodes. 2. Comput. rewrite or convert (programs or software) into a lower level language: some of the libraries written into C were downcoded into assembly.DERIVATIVES: down·cod·ing n.