Certain aspects of the present disclosure relate to quasi co-location assumptions for aperiodic channel state information (CSI) reference signals (RS) in communications systems operating according to NR techniques. An exemplary method that may be performed by a UE includes determining a quasi-co-location (QCL) relationship of an aperiodic channel state information (CSI) reference signal (CSI-RS) to a physical channel and processing the aperiodic CSI-RS according to the determined QCL relationship.