A new model of impedance-based structural health monitoring (SHM) using the spectral element method (SEM) and electric circuit analysis has been developed. This model provides additional information for more accurately identifying and locating damage and in designing the SHM system. Complex functions of the SHM system such as estimation of remaining life are also made possible with the use of the model. The circuit analysis can be applied to any type of structural model. However, since impedance-based SHM relies on high frequency excitation of the structure using piezoelectric patches, finite element modeling may not be applicable and instead the spectral element method (SEM) is used. SEM more accurately models higher frequency vibrations since the mass is modeled “exactly” and incorporates higher order models more easily. Model and experimental results are presented for damaged and undamaged specimens.