Originally Posted by
sillypainter
The 75 dollar change applies to any change that occurs on your itinerary e.g. Class change or airline change in the 21 day window, outside of that window you can do unlimited changes (not sure about class change, but I think same applies for that) as long as the departure and return points are the same.
If have some sort of status with UA its even better
50/25/0/0$ change fee for Silver/Gold/plat/1K.