A mobile communication system, a base station device, a mobile station device, a communication method, and an integrated circuit that each can efficiently transmit HARQ-ACK and/or channel state information are provided. A mobile station device includes means for receiving a first parameter that is used for instructing whether simultaneous transmission of information relating to HARQ-ACK and channel state information is allowed or not; and means for receiving a second parameter that is used for instructing whether simultaneous transmission of the information relating to HARQ-ACK and the channel state information is allowed or not, and controls a transmission method of the information relating to HARQ-ACK and the channel state information based on the first parameter, the second parameter, and whether or not the information relating to HARQ-ACK corresponds to transmission on a single physical downlink shared channel only on a primary cell.