The Parallel Unstructured Mesh Infrastructure for PIC (PUMIPic) calculations employs the GPU based Omega_h mesh infrastructure to support the execute of passively parallel PIC calculations on GPUs employing alternative element centric particle data structures. PUMIPic supports the parallel gather, scatter, and particle migration and provides APIs for the core particle/mesh operations used in a PIC code. PUMIPic also includes a procedure to regain load balance as particles migrate through the mesh. PUMIPic has demonstrated excellent scaling on Summit to 4,096 GPUs.