We have tested four recent quantitative magnetospheric magnetic field models to determine whether the magnetic field configuration is consistent with a balance of forces between the J¿B force and the gradient of the pressure. A necessary condition for the models to be consistent with an isotropic pressure distribution is that curl (J¿B) vanish. None of the models (Olson-Pfitzer, Tsyganenko, Hedgecock-Thomas, and Beard) meet this requirement: Our analysis indicates that the models are intrinsically inconsistent with momentum balance with any isotropic pressure distribution. We have also, for purposes of comparison, examined ∇⋅B. In certain models this can be nonzero.