  The status of core collapse supernoova progenitor models is reviewed with a
focus on some of the current uncertainties arising from the difficulties of
modeling important macrophysics and microphysics. In particular, I look at
issues concerned with modeling convection, the implications of the still
uncertain 12C(alpha,gamma)16O reaction rate, the uncertainties involved with
the incorporation of mass loss, rotation, and magnetic fields in the stellar
models, and the possible generation of global instabilities in stellar models
at the late evolutionary stages.
