A full wave description of electromagnetic coupling occurring in circuits has to consider time delays. The retarded partial-element equivalent-circuit (rPEEC) method is one of the approaches which allows us to take time delays resulting in a set of neutral functional differential equations into account. Due to the fragility of electromagnetic solvers, the asymptotic stability is a key issue in PEEC modeling. This paper presents an innovative method, based on linear matrix inequalities, to study the input-to-state stability of PEEC models with multiple noncommensurate time delays. Numerical results are given to illustrate the effectiveness of the proposed method.