A terminal apparatus and a base station apparatus efficiently communicate. A terminal apparatus including a receiver configured to receive an RRC message including first configuration information and to receive DCI on a PDCCH, a determination unit configured to determine a time parameter for transmitting a PUSCH, based on a bit sequence indicated by a first field of the DCI, and a transmitter configured to transmit the PUSCH, based on the time parameter. A relationship between the bit sequence and the time parameter is defined by a first parameter group in a case that a first condition is satisfied and that the first configuration information includes the first parameter group and the relationship between the bit sequence and defined by a second parameter group in a case that a second condition is satisfied and that the first configuration information includes the second parameter group.