The broadband service of 5G is already here and progressively the major Internet of Things (IoT) use cases are being addressed. Due to the diversity of the IoT application requirements, in addition to 5G, LTE-M (Long Term Evolution for Machines) and NB-IoT (Narrowband-IoT), two inherited 3GPP technologies based on 4G LTE, will continue to play a role in addressing the wide range of requirements. NB-IoT and LTE-M networks will coexist with 4G and 5G mobile networks and will benefit from all the security and privacy features of mobile networks, such as support for user identity confidentiality, entity authentication, data integrity and identification of mobile equipment. Despite commercial launches of LTE-M and NB-IoT networks that are available in several countries and reached more than 1.5 billion connections early in 2020, NB-IoT and LTE-M continue to evolve in terms of capabilities to address the massive aspect of IoT. Furthermore, 5G networks will be able to support the enormous amount of data that smart cities will generate, and will address many of the most promising IoT use cases, such as industrial automation and remote surgery that require ultra-low latency.