The main physical mechanisms of operation of bipolar semiconductor transistor structures referred to as bipolar magnetosensitive structures (BMS) are analyzed. It is demonstrated that vertical magnetosensitive structures must be excluded from the BMS class, whereas horizontal structures form one class from the viewpoint of model representations irrespective of the direction of their magnetic axis. The mechanisms of BMS sensitivity in which the determining parameter is the mobility of carriers admit a common model representation and hence can be considered as a common redistribution mechanism. The BMS magnetic sensitivity, when estimating its conversion efficiency, is sufficiently correctly described by the one-dimensional continuity equation irrespective of the concrete boundary conditions.