Originally Posted by
Duke787
Yes all terminals are connected airside. The only time you have to reclear is if you are arriving on an international flight
This means you can access the TK/BA/AF/LH lounges even if flying in/out of C and D on United
Correct. Take the Aerotrain or the mobile lounges (aka moon buggies) between terminals; you can even walk in some cases. Ask the "airport ambassadors" when you get there - they will give you directions.