International arriving passengers on United (and most of their Star Alliance partners at Dulles) who are making a connection through Dulles, and have their checked bags tagged for the connection, need to follow the TRANSFER sign for customs in the mid-field facility (C Concourse). After Passport Control you need to collect your checked bags.

If at that point you don't want to make the connection you have two choices about the checked bags. (1) After clearing the customs exit (where your blue customs form is collected) you can refuse to put your bags on the re-check belt - then take them through TSA security; into the C Concourse; and take the train to the Terminal building. (2) Before clearing the customs exit, stop at the United service counter in the baggage claim area; have your checked bags re-tagged for delivery to carousel 3 in the Terminal; after the customs exit drop the re-tagged bags on the re-check belt; go through TSA security; head for the Terminal and collect your bags on carousel 3. It might take 45 minutes for your bags to get to carousel 3 in the Terminal - and it will take you 20-30 minutes to get there yourself.

If you don't want to make the connection, it would be easiest if your checked bags were tagged only to Dulles. Then you would follow the signs for ARRIVALS; take the Mobile Lounge to IAB for customs; collect your bags; and leave the airport.