Many ultra-high-energy neutrino-detection experiments seek radio wave signals from neutrino interactions deep within the polar ice, and an understanding of in-ice radio wave propagation is therefore of critical importance. The parabolic equation (PE) method for modeling the propagation of radio waves is a suitable intermediate between ray tracing and finite-difference time domain (FDTD) methods in terms of accuracy and computation time. The RET collaboration has developed the first modification of the PE method for use in modeling in-ice radio wave propagation for ultra high energy cosmic ray and neutrino detection experiments. In this proceeding we will detail the motivation for the development of this technique, the process by which it was modified for in-ice use, and showcase the accuracy of its results by comparing to FDTD and ray tracing.