A user equipment device (UE) may create efficient Packet Data Convergence Protocol (PDCP) status reports. The UE may receive PDCP packets from multiple radio access technologies (RATs) using the same bearer or same RAT using split bearers. The UE may identify packets that the UE should have received but did not, and may create a status report based on the sequence numbers (SNs) of the packets that the UE failed to receive or based on the SNs of the successful packets. The report may include the SNs of the packets, in addition to a bit-length of the SNs and/or a starting point of the SNs in the status report. Alternatively, the report may include the SN of a first packet that the UE failed to receive and offset values (relative to the SN of the first packet) for the other packets that the UE failed/succeed to receive.