After configuring the American Contractor Bid preferences and pressing Run, Estimating will create the American Contractor Bid.
Many of the features and functions of the American Contractor Bid are the same as a traditional Estimating Summary.
If the American Contractor Bid has any Change Orders associated with it, these reports will be displayed in the panel on the left of the screen.
When the American Contractor Bid is ready, using 
or File > Export to AC
command will export the Bid to the American Contractor program.