FIFO memory devices are configured to support a pair of hybrid operating modes that enable the FIFO memory device to be depth-expandable with other FIFO memory devices in a collective standard mode of operation. The pair of hybrid operating modes including a first hybrid mode that supports a write interface configured in standard mode and a read interface configured in first-word fall-through (FWFT) mode and a second hybrid mode that supports a write interface configured in FWFT mode and a read interface configured in standard mode.