Nonrelativistic calculation of the Lamb shift for non-S-states of the hydrogen atom

It is shown, for the first time to our knowledge, that the Lamb shift for non-S-states of hydrogenic atoms can be completely calculated by applying the methods of nonrelativistic quantum electrodynamics and without using the Dirac equation and the second quantization for the electron. By taking into account the spin-orbit interaction the complete Lamb-shift result to order of α5 is derived and explicitly evaluated for different non-S-states.