A nonvolatile memory device is provided as follows. A memory cell array includes a plurality of memory cells. An address decoder provides a first verify voltage to selected memory cells among the plurality of memory cells in a first program loop and provides a second verify voltage to the selected memory cells in a second program loop. A control logic determines the second program loop as a verify voltage offset point in which the first verify voltage is changed to the second verify voltage based on a result of a verify operation of the first program loop.