Transfer - Houston's George Bush Intercontinental Airport

  
To transfer from a domestic United Airlines flight to an international flight at Houston's 
George Bush Intercontinental Airport (IAH), you'll likely arrive in Terminal C, and can then
either walk or take the SkyTrain (landside automated people mover) to Terminal D/E, where
international flights depart. 

Here's a more detailed breakdown:

Arrival:

United Airlines primarily uses Terminal C for domestic arrivals and departures, and Terminal E
for international arrivals and long-haul international departures. 

Transfer Options:

Walking: You can walk from the north part of Terminal C to Terminal D. 

SkyTrain: Take the SkyTrain (landside automated people mover) from Terminal C to Terminal D/E.
 
International Processing:

After arriving at Terminal E, you'll proceed through Customs and Immigration to the Terminal E
international arrivals hall. 

Re-checking Bags:

If your bags are not checked through to your final destination, you'll need to re-check them at
the United re-check desk located in Terminal E. 

Security:

All international in-transit passengers will be subject to screening at the TSA security checkpoint
before proceeding into the secure area of their departing terminal.