Same as Departures level, passengers of all flights arriving at Dulles International Airport, domestic or international, should go through TSA security screening upon their entry to the United States. The same rule applies even if you are connecting domestically or internationally.
Always be sure to have enough time between the flight, because sometimes security procedures can take a long time, depending on the weather or flight delay.
Passengers are supposed to go through a body scanner while their checked-in baggage and electronic devices are scanned separately. It is essential to comply with all the requirements of security agents and be honest while answering your questions.
As mentioned above, Dulles International Airport has three terminals. Terminal 1 is for departure – ticketing/ check-in; Terminal 2 arrivals level- baggage claim. And finally, Terminal 3 Ground transportation and parking
Customs and Border Protection
When reaching the United States, international passengers should go through an additional screening with Customs and Border Protection (CBP) agents, there is no re-entry so make sure to collect all of your luggage, while the passengers that are connecting to another flight need to re-heck their bags and go through TSA. You should always explain the reason for your stay and be honest with your answer also for immigration status.
After security checkpoints and clearing customs, passengers are welcomed to start their journey in D.CD.C.