Mobile Worldwide Interoperability for Microwave Access (Mobile WiMAX) is a wireless access technology based on IEEE 802.16e standard. Mobile WiMAX supports mobility, high utilization of radio resources, beneficial Quality of Service (QoS) framework, and flexible centralized scheduling, which are offered by connection oriented MAC layer. Due to the architecture of MAC layer in mobile WiMAX, admission control, packet scheduling, handover, and load balancing mechanisms can be implemented in the MAC layer by vendors. In this paper, we explain two main features in MAC layer of Mobile WiMAX networks; handover and load balancing. Additionally, we investigate load balancing algorithms suggested in wireless and WiMAX networks to find out appropriate way of load balancing in mobile WiMAX networks.