Originally Posted by
PVDtoDEL
Since when does US operate BOS-SFO?
If you are connecting in BOS, then keep in mind that you need a terminal switch to get to either CO or UA.
Are both flights on a single PNR? Which carrier issued the ticket?
OP's post says that he is flying UA xBOS and knows that he has to switch terminals. He asks about interline bag check and checkpoint delays.