Certain aspects of the present disclosure provide techniques for random access channel (RACH) communication. For example, certain aspects provide a method for wireless communication by a user-equipment (UE). The method generally includes transmitting a first message comprising a RACH preamble, receiving a second message comprising random access response (RAR) in response to the RACH preamble, transmitting a third message in response to the RAR, receiving a fourth message (MSG4) comprising a contention resolution message in response to the third message. In certain aspects, the fourth message may include a timing advance (TA) parameter which may be used to communicate one or more messages.