A model and parameter extraction method for a via-to-SIW transition is presented. The model is derived from an analysis of experimental data and full-wave simulations, allowing to obtain the equivalent circuit parameters for the via including its interaction with the SIW. It is demonstrated through a careful model-experiment correlation that the application of this method allows the correct representation of the via-to-SIW transitions implemented on printed circuit board technology even when changing the structure of the SIW environment.