Methods, systems, and devices for wireless communications are described for providing acknowledgment feedback in sidelink communications. A sidelink transmitting UE may receive a resource grant for a sidelink communication with one or more other UEs and may transmit the sidelink communication in accordance with the grant. The transmitting UE may then monitor for acknowledgment feedback from the one or more other UEs and generate sidelink acknowledgment feedback. A joint communication that provides both downlink acknowledgment feedback and the sidelink acknowledgment feedback may be provided to a serving base station. The transmitting UE may also multiplex sidelink acknowledgment feedback for each of two or more other UEs in a communication to the serving base station. The serving base station may determine whether any resources for retransmissions are to be granted based on the acknowledgment feedback.