To provide a base station apparatus, a terminal apparatus, and a communication method capable of efficiently performing retransmission control for small size data in grant-free multiple access where the base station apparatus accommodates a large number of terminal apparatuses. The base station apparatus for communicating with multiple terminal apparatuses, the base station apparatus including a receiver configured to receive an identification signal identifying a terminal apparatus having transmitted uplink data and the uplink data, and a transmitter configured to transmit a delivery confirmation signal for the uplink data, wherein the delivery confirmation signal includes a bundled delivery confirmation signal for the uplink data received on an identical time resource and an identical frequency resource, and a delivery confirmation signal for each terminal apparatus, the bundled delivery confirmation signal is associated with a parameter shared by the terminal apparatuses having transmitted the uplink data received on the identical time resource and the identical frequency resource, and the delivery confirmation signal for each terminal apparatus is associated with a parameter specific to the terminal apparatus.