Will an unlocked phone from Europe work in the US?

I bought an iPhone from Greece which is unlocked.

I will be moving in the US for studies (4 years) in December.

Will my phone work?
Or do I have to buy a new one from a company there that also combines services?

SSP Bowl Dude2016-09-17T10:41:11Z

It will work for voice and texts. It may work for 2G data. It probably won't work for MMS, and 3G and 4G data.

You won't be able to use Verizon, Sprint or US Cellular.

Zein2016-09-17T10:24:41Z

Yes.