PT_SOLVER is a modular, parallel, multi-regional, implicit transport equation solver built over the Plasma State and other publicly available (NTCC) libraries. The new solver has been installed, tested, and is available for use in predictive TRANSP (PTRANSP), but the solver itself does not depend on PTRANSP internals. In PTRANSP, the solver is used to integrate the highly nonlinear time-dependent equations for ion, and electron temperatures and densities, and angular momentum with implicit Newton iteration methods. The user controls choice of transport models attached to the solver, with a wide range of neoclassical and/or turbulent, or semi-empirical or data driven choices available. Available turbulent transport models include: MMM series, GLF23, and TGLF. For the more expensive transport coefficient models such as TGLF, a multi-level, communicator splitting method is used to parallelize the computation of transport coefficients using MPI, which allows the code to run simutaneously with different neoclassical and turbulent model, such as TGLF model and NEO model on different computing nodes.