In this paper, dynamic spectrum access scenario where cognitive terminal having multi-homing capability dynamically access frequency bands assigned to different radio access networks is considered. For this scenario, QoS-guaranteed loadbalancing dynamic spectrum access algorithm is proposed. For each cognitive terminal, this algorithm selects wireless access nodes to connect to. Also, it selects amount of data to transmit via each connection. Performance of the proposed dynamic spectrum access algorithm is compared to SINR-based and load-balancing vertical handover algorithms using simulation. It is shown that the proposed load-balancing dynamic spectrum access algorithm has considerable network capacity gain compared to both load-balancing and SINR-based vertical handover algorithms. Compared to load-balancing handover algorithm, this gain is equal to 10-40 % depending on traffic rate per cognitive terminal.