SAT Lawyer

The lounge will be most convenient for the international carrier departures at Terminal D (AF, AM, BA, BR, CA, EK, KE, KL, LH, NH, QR, SK, SQ, TA, TK, VB, 4O, and Y4), followed by international arrivals connecting onwards (all customs and immigrations exits just south of D for flight connections), followed by UA Terminal C-North flights, followed by UA Terminal E flights, followed by UA Terminal C-South flights, followed by UA regional Terminal B flights, followed by Terminal A flights (a limited number of additional UA regionals, AA, AC, DL, F9, and NK).

I'd say Terminal D, international arrivals, Terminal C-North, and Terminal E gates from E10 through E14 would be convenient, the others somewhat less so. But being airside and accessible by the above-ground train, it shouldn't be more than 15 minutes from any gate at IAH. Unlike many other airports, once you're airside, you can move freely from terminal to terminal at IAH without having to clear security again. From D, E, and C, you'd walk; from B and A, you'd take the above-ground train and walk. No terminal will be out of reach, but if you were connecting from a B gate to a B gate on UA Express, to give an extreme example, you'd chew up 15 minutes on each end of your lounge visit to enjoy it during your layover.