In a method of writing data in a nonvolatile memory device, a write command, a write address and write data to be programmed are received. Offset information representing a verification level is received. The offset information is provided when the write data corresponds to a distribution deterioration pattern by checking an input/output (I/O) pattern of the write data. When the offset information is received, the write data is programmed based on the offset information such that at least one state among a plurality of states included in a distribution of threshold voltages of memory cells in which the write data is stored is changed.