The US Cellular website did mention that the update will bring your respective device up to Android 5.1.1 Lollipop, where it will be baseband G920R4TYU2BOF7. You can also make the update via Samsung Kies should you decide to hook up your device to a computer or notebook. As for the Over The Air (OTA) update, it will be made available to those who would like to perform the update via the “traditional” method, that is, Settings -> About Device -> Software Update.
If you decide on the OTA route, do make sure that you are hooked up to a Wi-Fi network beforehand, so as not to eat into your data plan. Needles to say, you will also need a Google account before you continue, and the entire update will weight a few hundred MBs in size. There is no change log released for the updates however, but perhaps it will arrive later on.