My area does not currently have LTE yet and my iPhone 5 always connects as 4G. However, yesterday I put my phone into Airplane mode and then back out of it, and to my surprise my phone connected to LTE.
To see if it were just a fluke I ran speed tests and on LTE my speeds are extremely faster. Now for the catch; after my phone auto locks after being idl for a while, it is back on 4G.
Is this a case of they haven't officially rolled LTE out yet?
Speeds recorded: 4G LTE: 22.29 Mbps down / 5.09 Mbps up with 52ms 4G: 3.08 Mbps down / 1.79 Mbps up
In many cases you may notice that LTE will pop up in your area when the Network is testing the network. Prior to the launch in my area you would see it active sometimes for a few seconds to a few hours. You can always check the network maps online AT&T Network Maps
If LTE has launched in your area and you are having issues with connecting to the network, you should visit a Corporate AT&T store to have your SIM card changed and/or ensure your account is properly set up.
*I am an AT&T employee and the postings on this site are my own and don't necessarily represent AT&T's position, strategies or opinions.