A nonvolatile memory device comprises a memory cell array comprising a plurality of memory cells, a voltage generator configured to generate voltages to program the plurality of memory cells, and a control logic component configured to control the voltage generator to provide a plurality of program voltages to selected memory cells during successive iterations of a program loop. Wherein where memory cells corresponding to one logic state are judged to be program passed during a current iteration of the program loop, the control logic component controls the voltage generator such that a program voltage corresponding to the one logic state is skipped during subsequent iterations of the program loop.