Four magnetospheric magnetic field models are compared on the basis of the current systems they represent, their agreement with observations, and their computational performance. These models are the Olson-Pfitzer dynamic (1988), Tsyganenko 1989, Hilmer-Voigt, and Olson-Pfitzer tilt-dependent (1977). The models are summarized in terms of their components: the main field, the ring currents, the tail currents, and the magnetopause. Differences among the models must be considered when determining which is best for a specific application. The models are evaluated using data from CRRES during both quiet and storm time conditions on August 26, 1990. CRRES is in a geosynchronous transfer orbit with perigree at 360 km and apogee at 33 000 km. Thus, the focus of our comparisons is on the inner magnetosphere out to about 6.3 RE (distant tail properties will not be discussed). Tsyganenko 1989 is a good average model of the magnetospheric magnetic field for various Kp levels. Olson-Pfitzer dynamic and Hilmer-Voigt both clearly show changes in the magnetic field due to the compression of the magnetopause as determined from the standoff distance. Hilmer-Voigt is the most flexible model as it has a parameter to specify the position of the inner edge of the plasma sheet, but it is also the slowest to execute. Olson-Pfitzer dynamic showed the best agreement with the data presented here. ¿ American Geophysical Union 1992