An efficient on-chip infrastructure for memory test and repair is crucial to enhance yield and availability of SoCs. Most of the existing built-in self-repair solutions reuse IP-Cores for BIST without modifications. However, this prevents an optimized test and repair interaction. In this paper, the concept of modular BIST for memories is introduced, which supports a more efficient interleaving of test and repair and can be achieved with only small modifications in the BIST control