A communication terminal capable of determining whether or not it can perform DC, a base station, and a communication method are provided. A communication terminal (30) according to the present disclosure includes a communication unit (31) that simultaneously communicates with a master base station (10) associated with a first radio access technology and a secondary base station (20) associated with a second radio access technology, and a control unit (32) that specifies, when it is notified by the master base station (10) that it can provide dual connectivity using the second radio access technology, at least one frequency band supported by the secondary base station (20), the secondary base station being configured to provide the dual connectivity in cooperation with the master base station (10).