Samsung's Galaxy S9 and Galaxy S9+ U.S. models seem to have hit the FCC very recently as a set of new documents from the report show that the two devices listed as SM-G960U and SM-G965U have now arrived at the agency for testing. These two model numbers are already suggested to be the model numbers meant for the U.S. market as they match up with the model numbers for the U.S. models of the Galaxy S8 and Galaxy S8+ that were launched last year, which is a decent indicator as Samsung usually keeps these things the same when it launches a new model in its smartphone lineups.
Another piece of information that points to these being the U.S. versions of Samsung's 2018 flagship smartphones are the network frequencies which have been tested with these two phones. In the second screenshot below you can see a list of the tested LTE bands, which includes all of the LTE bands and other network frequencies for the U.S.' four major wireless carriers - T-Mobile, Verizon, AT&T, and Sprint. This includes LTE bands 2, 4, 5, 12, 13, 14, 17, 25, 26, 29, 30, 66, 71, and 41.
In the first image you can see where the FCC label is going to be located, although the diagram doesn't really give up any telling information about the device design, so this really does nothing but indicate where the FCC is placing its label and logo, which is going to be on the back of the device all the way at the bottom. While this is the first appearance at the FCC of the U.S. versions for the Galaxy S9 and Galaxy S9+, models for a different region showed up at the FCC back on December 28th sporting the model numbers SM-G960F and SM-G965F. More recently it was also reportedly confirmed that Samsung plans to unveil the Galaxy S9 and Galaxy S9+ at Mobile World Congress next month, so more versions of the two phones showing up at the FCC right about now seems to be good timing. Samsung's Galaxy S9 has been rumored to keep the single rear-facing camera sensor while the Galaxy S9+ is rumored to come with dual cameras on the back, while both are expected to come with Qualcomm's Snapdragon 845 CPU for the U.S. models.