A nonvolatile memory device includes a memory cell array including a plurality of first segments having a write data, and a plurality of second segments having a programmed information defining a programmed segment from the plurality of first segments. A randomizer is configured to randomize the write data. An error correction circuit is configured to perform an error correction operation on the write data. A control logic is configured to determine the programmed information from an address received from a memory controller, and to determine whether to operate the randomizer and the error correction circuit based on the determination of the programmed information during the program operation. A page buffer is configured to store the write data and the programmed information during the randomizing and the error correction operation.