UAX at IAH using both TA and TB. Beware!
 

I recently had a flight on UAX out of IAH. Virtually always Terminal B. That day the online status said "Gate A-8. Terminal A." So, I got dropped off by parking shuttle at TA only to find that there is no UA ticket counter in use at TA, only a sign saying to check in at Terminal B if checking bags, which I was.
So... I had to take the underground tram to TB to check my bag. I asked the agent about it and she said they have BEGGED the company to either staff their counter positions in TA OR clearly state on the website to check in at Terminal B.
Since I bat .100 at PREcheck I sometimes cut my arrival time at the airport a little short. I went ahead and cleared TSA at TB and took the secure AirTran (or whatever it's called) back to TA, getting there about five minutes before boarding. There happened to be a supervisor at the gate and I discussed it with him. He said that they are using TA while they undergoing Phase 2 of reconstruction at TB. He said that the confusion I faced has been a major problem and has been much discussed.

I was fortunate that I am pretty fit and know my way around IAH. What about some elderly couple or non-English speaking family who get dropped off at the advertized terminal, only to find there is no one there to help them?

It's bad enough to check in at B and be told you have to go to another terminal for your flight. But to show up at the assigned Terminal A, have to go back to B to check in, THEN return once more to Terminal A is just asinine. It's a bad situation and is entirely preventable. They could easily show in Flight Status "Check Bags in Terminal B before proceeding to Gate A-8" or some such language.

Thank you for the insight. You make some very valid points.