A systematic approach to corrosion modeling in microelectronic devices is formulated in terms of the fundamental steps of corrosion processes and the rate determining step. The corrosion modeling starts with the identification of corrosion sites and corrosion products, followed by the determination of reaction controlled systems, the anode and cathode.  For surface electrochemical reaction controlled systems, the Butler-Volmer equation is used to model the corrosion processes.  For mass transport limited systems, the continuity equation and a generalized mass transport equation with both concentration gradient and potential gradient driving forces are used.  When the concentration variation goes to zero, the combination of the mass transport equation and the charge conservation equation produces a corrosion rate equation associated with the Ohm's law.  The time to corrosion failure is calculated by combining the corrosion rate equation and Faraday's equation.