Separable potentials in a non-relativistic model are used to calculate Coulomb corrections to pi ⁺p and pi ^-p phase-shifts and to calculate the strong interaction effect in pi -mesic hydrogen. The latter effect, which consists of an energy level shift of the Coulomb ground state, is compared with model-independent predictions. The strong-interaction effect is an important quantity for obtaining information about the hadronic interaction. The authors' model confirms an energy shift of about -7 eV.