  Accurate total reaction cross section models are important to achieving
reliable predictions from spallation and transport codes. The latest version of
the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the
Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos
National Laboratory (LANL), each use such cross sections. Having accurate total
reaction cross section models in the intermediate energy region ($\sim$50 MeV
to $\sim$5 GeV) is very important for different applications, including
analysis of space environments, use in medical physics, and accelerator design,
to name just a few. The current inverse cross sections used in the
preequilibrium and evaporation stages of CEM are based on the Dostrovsky {\it
et al.} model, published in 1959. Better cross section models are available
now. Implementing better cross section models in CEM and MCNP6 should yield
improved predictions for particle spectra and total production cross sections,
among other results. Our current results indicate this is, in fact, the case.
