In this article, we investigate the plug-in electric vehicle (PEV) integrated smart grid for efficient system operation. Due to the stochastic characteristics of PEVs, the intermittent nature of renewable energy sources, and the heterogeneity of the devices, it is a great challenge to achieve system flexibility, reliability, and interoperability. To address these issues, we propose a two-tier SDN-based framework for the PEV integrated smart grid. The upper tier targets the primary feeder level to have a general view of the system, while the lower tier focuses on the secondary feeder level to achieve granular control of data and power operation. The framework is presented hierarchically, followed by a detailed explanation of the system operation in each tier. In particular, the integration of PEVs, which includes both PEV charging and V2G, is well illustrated in the SDNbased framework. Finally, we provide a case study to validate the emerging need for SDN deployment in the smart grid.