The report documents the computer programs of the Bent Ionospheric Model and briefly describes the development of the model. The FORTRAN Program is designed for general use and can generate ionospheric data on a world-wide basis for any past or future date. For a given condition consisting of station, satellite and time information, the electron density versus height profile is computed from which range, range rate, and angular refraction corrections as well as vertical and angular total electron content are obtained. The model has the additional capability of improving its predictions by updating with actual ionospheric observations. Considerable tests in the past have proved this empirical model highly successful. Also included in the documentation is an alternate version of the ionospheric program to be used when stringent space and time requirements are imposed by the operating system. However, several options of the standard program are not incorporated and the accuracy of the results is somewhat reduced.