In this paper, we propose a new program (PGM) transient model for three-dimensional (3-D) gate-all-around (GAA) cylindrical NAND flash memory. An emission term is added to previous models and is combined into a compact form with distinct acceptor/donor-like trap levels. The continuity equation is solved, including Shockley–Read–Hall (SRH) recombination theory to track the concentration of the conduction band (CB) free electrons. The threshold voltage transient is obtained from the electron/hole concentrations, and single/incremental step pulse programming (ISPP) pulse experimental data are calibrated with the model to check its validity.