A memory module for reporting information about a fail in chip units, an operation of a memory module, and an operation of a memory controller are provided. The memory module includes: first to Mth memory chips (where M is an integer that is equal to or greater than 2) mounted on a module board and storing data, and an (M+1)th memory chip mounted on the module board and storing a parity code for recovering data of a memory chip in which a fail in chip units occurs among the first to Mth memory chips, wherein fail bits are generated from the first to (M+1)th memory chips through an intra-chip error detection operation, and fail information is output according to a result of calculating the fail bits from the first to (M+1)th memory chips.