Design of fully-integrated push-pull class E/Fodd power amplifier for NarrowBand Internet of Things. Cascode switch is utilized with source switching instead of gate switching to accommodate the high drain voltage stress. Proposed PA is implemented using a 40 nm CMOS process with a 3.3 V supply for the core and a 1.2 V supply for the driver stage. Post-layout simulations show that the PA achieves peak power added efficiency of 58.13 % at peak output power of 31.12 dBm for the target frequency band 824-849 MHz. It also achieves a linear performance for the non-constant envelope signal imposed by the Single Carrier Frequency Division Multiple Access with an average power added efficiency of 43.85 %.