Electronic conduction in metal-insulator-metal (MIM) diodes is categorized as bulk-limited or electrode-limited. An overview of representative conduction mechanisms is described through mathematical current-voltage equations and the use of energy band diagrams. An analytic methodology for Fowler-Nordheim tunneling, an electrode-limited conduction mechanism, is described in detail. Tunneling MIM diode current-voltage data is presented to illustrate modulation of current-voltage characteristics via fabrication parameters.