In one example embodiment, a memory module includes a plurality of memory devices and a buffer chip configured to manage the plurality of memory device. The buffer chip includes a memory management unit having an error correction unit configured to perform error correction operation on each of the plurality of memory devices. Each of the plurality of memory devices includes at least one spare column that is accessible by the memory management unit, and the memory management unit is configured to correct errors of the plurality of memory devices by selectively using the at least one spare column based on an error correction capability of the error correction unit.