U.S. Department of Energy high-performance computer sites have selected a dynamic fusion code, called XGC, for optimization on three powerful new supercomputers. XGC, a code for simulating the behavior of transport barrier particles, was one of only three codes selected to participate in Early Science programs on all three new machines, including the Argonne National Laboratory's Aurora. Among the team of nationwide experts developing this code are Princeton Plasma Physics Laboratory physicists C.S. Chang, Seung-Ho Ku, Robert Hager, and Stephane Ethier.