We are leaving Rome (FCO) and flying into Dulles (IAD; Washington DC) with a layover in Frankfort. When we land in Frankfort for our layover what do we need to do?? Grab luggage and clear customs or just go directly to our next gate for our flight to IAD??
You clear customs at Dulles and your luggage should be checked to there from FCO. You will have to pass through Schengen passport control to get your passport stamped as departing the Schengen Treaty Zone.
Also - when at Dulles, unless you are Global Entry, remember to use the very easy and quick "Mobile Passport Control" app to get yourself right through the long lines. Fill out everything before landing except don't "submit" until you are there in line. I have never waited more than 5-10 minutes to get a place in line at the passport Control desks.
As Sam said, you go thru passport control in Frankfurt. Just follow the signs, then on to your gate. US Customs will be in Washington DC, again just follow the signs.