Originally Posted by
DataPlumber
It will be an easy connection. There is an airside shuttle bus (no need to reclear security) between your domestic arrival at T3 and BA at T5. This link has great detail
https://www.travelcodex.com/chicago-...-terminal-bus/
The only additional detail not in this article, is a 3 bus stop from the L concourse extension at gate L25
However, I also read that this was only running until the autumn (fall) - so not sure if that has been extended.
But there should be a BA bus as well?