Multiphysics couplings are at the origin of many applications. In order to design devices with optimal coupling effects, advanced modeling tools are necessary. In this paper a generic formalism for the homogeni-zation of coupled magnetoelectrothermoelastic behavior is proposed. It is based on the decomposition in several contributions of the magnetic, electric, thermal, and mechanical fields. This decomposition makes it possible to use the classical homogenization tools developed in the framework of uncoupled behavior. The method is illustrated on the calculation of the effective properties of a magnetoelectric composite made of piezomagnetic and piezoelectric phases.