Checking in and departing from IAH:

Terminal C has the most reliably open Precheck and Premier Access security lanes. Consider checking in and clearing security in at Terminal C even if departing from another terminal.

There are no UA check-in counters in Terminal A, even though UA has a few flights that depart from Terminal A. Check in at Terminal B or C.

There is an underground, somewhat slow landside tram system (the Subway) that runs between the basement level of all terminals (plus the on-site Marriott hotel) outside of security. (The Subway was built by Disney and modeled after their PeopleMover ride. It's worth a look if you're into that sort of thing.)

Recommended practices for transiting IAH:

IAH is a huge airport, but all terminals are very conveniently connected by a very frequent, fast airside tram system (the Skyway) inside security. You can pretty much get from any point in the airport to any other point in the airport within about 15 minutes (with a combination of Skyway and a brisk walk) without reclearing security. UA publishes as low as a 35-minute minimum connect time (MCT) at IAH, and while you shouldn't dilly-dally, this is doable on a typical domestic-domestic connection. (It helps if your inbound is not delayed and you're seated towards the front of the plane, of course; your departure flight will be almost fully boarded by the time you get there, but you'll make it.)

Note that the higher-numbered C gates (C29-C45, aka "C South") are directly connected to the E terminal by a walkway. It is usually faster to walk from C South to E (especially the low E gates) than it is to take the train. Similarly, C North (C14-C27) are directly connected to the D terminal, though the Skyway is not really out of the way and is useful if going from a low C gate to a high D gate (C24 to D10, for example). Terminal A and Terminal B are not connected by any walkways, and you must use the Skyway to change to or from these terminals.

For international arrivals: after clearing customs, stay to the left of the baggage re-check belts and follow signs to exit to arrivals (like you're going to curbside). Once in the arrivals lobby, take the elevator or escalator up one floor to find a PreCheck checkpoint and a usually-less-crowded regular checkpoint. If you ignore this advice and proceed up the escalator behind the baggage re-check area, the transit security checkpoint there is often congested and does not have a separate PreCheck checkpoint.

While perhaps not usually recommended, in a pinch, with Global Entry, no checked bags, and PreCheck, it is possible to make a one-hour (or even slightly less) connection by following the above instructions specifically (on a good day, it can take less than 30 minutes from flight arrival to sitting in the Terminal E United Club, as one member reported in the thread). Without Global Entry and with checked luggage (which must be retrieved to go through customs and dropped back off after clearing customs), especially if you are a foreign resident, expect the immigration and customs process to take longer, so allow enough time accordingly. For UA-UA international-international connections (ITI), there is a special immigration line that usually moves pretty quickly, and your baggage will be checked through and does not need to be retrieved to go through customs. No need to collect checked luggage while transiting through IAH. [OneStop]

Again, do not follow signs for international connections up the escalator behind the baggage re-check area; exit to the arrivals waiting area and re-enter one floor above through normal airport security. A map follows for visual learners:

Terminal E arrivals level / departures level:



The marked elevator will spit you out literally directly in front of the PreCheck checkpoint.

Standard UA-UA MCT table for IAH:

Results from ExpertFlyer.comThere are lots of exceptions, though, and some specific flights have as low as a 35-minute MCT, which is doable as mentioned above. IAH is a very efficiently designed airport, and you should not worry about what appears to be an abnormally low connection time; if UA says your connection is valid, it is almost certainly doable within the allotted time (notwithstanding delays, of course, and standard advice regarding allowing longer connections for mission-critical travel or travel on separate tickets still stands).

Airport map, courtesy of United Airlines:
Map displays Star Alliance partners only; most non-Star Alliance airlines have domestic operations in Terminal A or international operations in Terminal D




Archive posts - Consolidated Connection time/logistics-Domestic & International at IAH [ARCHIVE]