Methods and apparatus are disclosed for operating a multi-mode wireless communications device to select a radio access technology (RAT) requiring the lowest energy consumption by the device for a desired operating mode. An exemplary method comprises scanning a plurality of frequency bands to determine a set of available radio access technologies that support the desired operating mode, and evaluating, for each available RAT, RAT-specific system parameters and RAT-specific operating conditions. Based on the evaluation, the RAT requiring the lowest energy consumption by the wireless device for the desired operating mode is selected.