As one of the candidate fourth-generation mobile communication systems, the IEEE 802.16 m-based WiMAX 2.0 system is required to provide up to 1 Gb/s peak transmission rate. The most efficient solution to achieve this challenging objective is to utilize wider channel bandwidth. Multicarrier is the technology to utilize wider bandwidth for parallel data transmission across multiple RF carriers, which is well agreed as one of the key technologies to satisfy ITU-R IMTAdvanced requirements. As the evolution of the IEEE 802.16 e-based WiMAX 1.0 system, IEEE 802.16 m specifies physical and MAC layers to enable multicarrier technology for the WiMAX 2.0 system. This can lead to more than 1 Gb/s peak transmission rate for low-mobility users and 100 Mb/s peak transmission rate for high-mobility users. By having the protocol structure with a common MAC entity to control transmission by multiple physical-layer connections over different RF carriers, the network operator can aggregate either contiguous or non-contiguous spectrum resources with higher deployment flexibility, user throughput, and spectrum efficiency. This article provides an overview of the multicarrier technology supported by the IEEE 802.16 m draft standard1 for WiMAX 2.0 system, including not only the general operation principle but also some details of physical layer and MAC layer support.