A numerical simulation of the low-altitude electron radiation belt is described. It includes dependences on the electrons' bounce and drift phases, equatorial pitch angle, and kinetic energy in the range of ~1 to several MeV at L = 3.5. Physical processes in addition to the adiabatic electron motion are pitch angle diffusion and backscattering from a realistic model atmosphere. Quasi-linear diffusion coefficients are calculated from a model of the whistler mode plasmaspheric hiss wave intensity. Comparisons of the simulation results with electron data from a low-altitude satellite show that the model accounts for the main features of the electron spatial distribution during selected periods of differing geomagnetic activity.