The covariant neutron‐exchange mechanism is formulated for12C(p,&pgr;+)13Cg.s. using relativistic wave functions obtained from nuclear models based on the Dirac equation for the (A+1) system. Ambiguities associated with the nonrelativistic reduction of the (&pgr;NN) vertex are eliminated. It is found that the (p,&pgr;+) results are surprisingly sensitive to the choice of pseudoscalar or axial‐vector (&pgr;NN) coupling.