This disclosure relates to methods, devices, and systems for wireless communications, and more particularly to aggregating physical uplink shared channel (PUSCH) resource units relating to a random access message. A user equipment (UE) may identify a random access message of a random access procedure. The random access message may include a random access preamble and a random access payload. The UE may aggregate multiple PUSCH resource units of a set of PUSCH resource units associated with one or more PUSCH occasions (POs) based on one or more of a payload size of the random access payload or a modulation and coding scheme associated with the random access payload. As a result, the UE may transmit the random access payload of the random access message on a PUSCH using time and frequency resources of the aggregated multiple PUSCH resource units over the one or more POs.