A terminal apparatus, which is able to establish a connection with a base station apparatus via a two-step random access procedure by transmitting a first signal including a random access preamble and predetermined information to the base station apparatus and receiving a second signal as a reply to the first signal from the base station apparatus, acquires a random access-radio network temporary identifier (RA-RNTI) on the basis of a radio resource having been used to transmit the predetermined information with the first signal, and executes reception processing of the second signal using the RA-RNTI.