The multiport scattering (S-) parameter matrix is increasingly utilized to compose models of large bit-width interconnect systems with broadband characteristics (frequency range of zero to tens of gigahertz) to perform increasingly accurate signal-integrity and power-integrity simulations. The search for an optimal solution space often requires generation of S-parameter models of interconnect systems for various signal/ground pin mappings, a process that can be computationally costly if the structure is electromagnetically solved for each distinct pin mapping. To expedite this model-generation process, we propose a method in which an N-port structure is electromagnetically solved only once to yield an N × N S-matrix; then, a linear system is formulated and solved to yield an (N − M) × (N − M) post-suppressed S-matrix (where M is the number of suppressed ports). This approach results in significant computational savings through elimination of electromagnetic field-solver runs for each distinct pin mapping. Included in this paper is a discussion about the limitations of this technique and several numerical examples. Copyright © 2013 John Wiley & Sons, Ltd.