Contrary to the other answers here, from what I understand via Sony's answers to the question on the Amazon FAQ, all models of the Xperia 1 II are 5G compatibile. The reason it is said to not be 5G in the US is that it supports the sub-6GHz band of 5G, whereas US carriers tend to support the mmWav high frequency band. For example, if you bought the US model and brought it with you to Europe, where sub-6GHz is more of the standard, it would connect to that 5G network. Same goes for if/when US carriers begin to also roll out more extensive sub-6GHz services. Hope this helps.