Provided is a terminal apparatus for communicating with a base station apparatus through a group including at least one or more cells. The terminal apparatus includes: a receiver configured to receive an RRC message from the base station apparatus; and a processing unit configured to perform processing of RRC. The processing unit causes, in a case that first information is included in the RRC message, a first timer to start to be in a running state, and considers, at least in a case that a random access problem indication is received from a MAC entity of the group in a state in which the first timer is not running, or in a case that a random access problem indication is received from a MAC entity of the group in a state in which the first timer is running under a specific condition, a radio link failure for the group to be detected. In a case that the radio link failure for the group is considered to be detected and that the first timer is running under the specific condition, the processing unit suspends transmission of all of radio bearers in the group, and resets the MAC entity of the group.